AC voltage adjuster - how to do cheaply
 

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Are you kidding? Forget about it and forget about the voltage variation.

--
_______________________________
Joel, P.E.



"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Are you kidding? Forget about it and forget about the voltage variation.

--
_______________________________
Joel, P.E.



"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

In one radio station in which I worked, they had some regulating transformers
that
would give 118 vac out with 95-135 volts in. There were taps to run it off 220,
which
they did, with an input of + or - 20 volts for 230 out. There was one thing that
should
be noted is that they get very warm if running near the rated load. They also
used to
hum a bit.

Leanne

AC voltage adjuster - how to do cheaply
 

In one radio station in which I worked, they had some regulating transformers
that
would give 118 vac out with 95-135 volts in. There were taps to run it off 220,
which
they did, with an input of + or - 20 volts for 230 out. There was one thing that
should
be noted is that they get very warm if running near the rated load. They also
used to
hum a bit.

Leanne

AC voltage adjuster - how to do cheaply
 

google "AC line regulation"

Go from there.

Rufus



Panama wrote:
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

google "AC line regulation"

Go from there.

Rufus



Panama wrote:
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

I would not really worry about the voltage out as long as it is greater then
13.7vDC it should charge the batteries fine. You should be able to pick up
a used variac off ebay or get one new from fisher scientific. They
generally will supply from 0% to 120% of the input voltage. You should wire
a volt meter into the variac to see your output voltage before you plug the
charger into it. We use tons of them to regulate our furnaces at school so
they are straight forward to wire just keep in mind they supply a % of the
input voltage. So if you are overdriving the output and the input ramps up,
the output side may be more voltage then what the charger can tolerate.

good luck,
mark

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

I would not really worry about the voltage out as long as it is greater then
13.7vDC it should charge the batteries fine. You should be able to pick up
a used variac off ebay or get one new from fisher scientific. They
generally will supply from 0% to 120% of the input voltage. You should wire
a volt meter into the variac to see your output voltage before you plug the
charger into it. We use tons of them to regulate our furnaces at school so
they are straight forward to wire just keep in mind they supply a % of the
input voltage. So if you are overdriving the output and the input ramps up,
the output side may be more voltage then what the charger can tolerate.

good luck,
mark

AC voltage adjuster - how to do cheaply
 

I don't know if this qualifies as cheap enough but one way is to use a
variable autotransformer, a transformer with a variable tap. With
120VAC in you can output from 0130 VAC.
Here is a link to a 10amp unit all cased up and ready to plug in. If you
are handy you can get the transformer itself for a lot less.
http://www.tenma.com/070.html
BTW, 9 amps seems kinda high, I would expect a 40amp charger to draw
about half that on the line side.
The other thing to keep in mind is that these use a wiper to vary the
tap, I have no idea how long that would last on a boat.
RB
..


Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

I don't know if this qualifies as cheap enough but one way is to use a
variable autotransformer, a transformer with a variable tap. With
120VAC in you can output from 0130 VAC.
Here is a link to a 10amp unit all cased up and ready to plug in. If you
are handy you can get the transformer itself for a lot less.
http://www.tenma.com/070.html
BTW, 9 amps seems kinda high, I would expect a 40amp charger to draw
about half that on the line side.
The other thing to keep in mind is that these use a wiper to vary the
tap, I have no idea how long that would last on a boat.
RB
..


Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Panama wrote:

.....Any ideas or products. Preferably cheap and never needs replacement

like the 27 years old charger.

(No I'm really not going to replace the charger.)

Is it less expensive to continually buy new batteries after your old cheap
battery charger fries them?

Priorities, man!

DSK

AC voltage adjuster - how to do cheaply
 

Panama wrote:

.....Any ideas or products. Preferably cheap and never needs replacement

like the 27 years old charger.

(No I'm really not going to replace the charger.)

Is it less expensive to continually buy new batteries after your old cheap
battery charger fries them?

Priorities, man!

DSK

AC voltage adjuster - how to do cheaply
 

I also have used the regulating transformers at large commercial on shore
radio/computer installations. Sola was the brand we used, one on each leg of
3 phase shore power. Some critical units had small single phase
transformers mounted in the rack. They covered about 95-135 volts in for
constant output. However, they take several cycles of power change for the
change to be seen at the output. I got into trouble having a large UPS unit
feeding the transformers, as the transformer change was slower than the UPS
and we got into a voltage bucking problem. Ended up taking the transformers
out and just using the UPS. Do a web search for Sola line regulator
transformers (they are really a mag amp autotransformer device). E-bay has
them from time to time.

Doug K7ABX

"Leanne" wrote in message
...
In one radio station in which I worked, they had some regulating
transformers
that
would give 118 vac out with 95-135 volts in. There were taps to run it off
220,
which
they did, with an input of + or - 20 volts for 230 out. There was one
thing that
should
be noted is that they get very warm if running near the rated load. They
also
used to
hum a bit.

Leanne

AC voltage adjuster - how to do cheaply
 

I also have used the regulating transformers at large commercial on shore
radio/computer installations. Sola was the brand we used, one on each leg of
3 phase shore power. Some critical units had small single phase
transformers mounted in the rack. They covered about 95-135 volts in for
constant output. However, they take several cycles of power change for the
change to be seen at the output. I got into trouble having a large UPS unit
feeding the transformers, as the transformer change was slower than the UPS
and we got into a voltage bucking problem. Ended up taking the transformers
out and just using the UPS. Do a web search for Sola line regulator
transformers (they are really a mag amp autotransformer device). E-bay has
them from time to time.

Doug K7ABX

"Leanne" wrote in message
...
In one radio station in which I worked, they had some regulating
transformers
that
would give 118 vac out with 95-135 volts in. There were taps to run it off
220,
which
they did, with an input of + or - 20 volts for 230 out. There was one
thing that
should
be noted is that they get very warm if running near the rated load. They
also
used to
hum a bit.

Leanne

AC voltage adjuster - how to do cheaply
 

On Tue, 25 Nov 2003 22:14:36 GMT, "Doug K7ABX"
wrote (with possible editing):

I also have used the regulating transformers at large commercial on shore
radio/computer installations. Sola was the brand we used, one on each leg of
3 phase shore power. Some critical units had small single phase
transformers mounted in the rack. They covered about 95-135 volts in for
constant output. However, they take several cycles of power change for the
change to be seen at the output. I got into trouble having a large UPS unit
feeding the transformers, as the transformer change was slower than the UPS
and we got into a voltage bucking problem. Ended up taking the transformers
out and just using the UPS. Do a web search for Sola line regulator
transformers (they are really a mag amp autotransformer device). E-bay has
them from time to time.

Doug K7ABX

I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.
--

Larry
Email to rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

On Tue, 25 Nov 2003 22:14:36 GMT, "Doug K7ABX"
wrote (with possible editing):

I also have used the regulating transformers at large commercial on shore
radio/computer installations. Sola was the brand we used, one on each leg of
3 phase shore power. Some critical units had small single phase
transformers mounted in the rack. They covered about 95-135 volts in for
constant output. However, they take several cycles of power change for the
change to be seen at the output. I got into trouble having a large UPS unit
feeding the transformers, as the transformer change was slower than the UPS
and we got into a voltage bucking problem. Ended up taking the transformers
out and just using the UPS. Do a web search for Sola line regulator
transformers (they are really a mag amp autotransformer device). E-bay has
them from time to time.

Doug K7ABX

I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.
--

Larry
Email to rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

Throw out that charger and get a good one. Those kinds of
variations in line voltage should not affect the output. I've
seen line voltages from 105 to 128 in our travels and the
battery charger always maintains the proper voltages and
currents. By the time you get a way to control the line
voltage you can by a new charger that works properly.

Doug
s/v Callista

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Throw out that charger and get a good one. Those kinds of
variations in line voltage should not affect the output. I've
seen line voltages from 105 to 128 in our travels and the
battery charger always maintains the proper voltages and
currents. By the time you get a way to control the line
voltage you can by a new charger that works properly.

Doug
s/v Callista

"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Sounds like you need an "autotransformer".

Many Variacs are actually autotransformers, in that they accept 110V input,
and output from 0 to 130 volts AC. The principle works as such:

=======================
mmmmmmmmmmmmmmmm
| | ^
A B C

If you supply the inputs to wires A and B, and outputs on A and C, and C is
the adjustable portion of the Vairac. If the voltage from A - B is 110
Volts, when C is farther out on the transformer, you will see a higher
voltage from A - C (above 110 Volts). When it is inside of B you will
reduce the voltage (below 110 Volts).

My bench Variac actually inputs 110V, and outputs from 0 to 220V.

You can also do this with a multi-voltage transformer:

Do not care about Secondary
==========================
mmmmmmmmmmmmmmmmmm
| | | | |
A B C D E
100 110 120 130
This is a common multi-input voltage transformer used in international
equipment, having inputs of 100, 110, 120, 130 Volts. This will typically
be a low voltage transformer, but you really don't care about the secondary
side.

If you typically see from 100 to 130 volts and you want 110 volts, you would
hook up the output to A-C. and the input to:

100V A - B
110V A - C
120V A - D
130V A - E

With this setup, you will boost or decrease the voltage depending on where
you have the input.

You will need to find a transformer large enough to supply your peak
wattage, and remember that even if you normally draw 9A at 110V, in the 100
V boost configuration, your input current will be 9.9A.

Also autotransformers DO NOT isolate the secondary from the line, so
electrical shock is still possible.


"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

Sounds like you need an "autotransformer".

Many Variacs are actually autotransformers, in that they accept 110V input,
and output from 0 to 130 volts AC. The principle works as such:

=======================
mmmmmmmmmmmmmmmm
| | ^
A B C

If you supply the inputs to wires A and B, and outputs on A and C, and C is
the adjustable portion of the Vairac. If the voltage from A - B is 110
Volts, when C is farther out on the transformer, you will see a higher
voltage from A - C (above 110 Volts). When it is inside of B you will
reduce the voltage (below 110 Volts).

My bench Variac actually inputs 110V, and outputs from 0 to 220V.

You can also do this with a multi-voltage transformer:

Do not care about Secondary
==========================
mmmmmmmmmmmmmmmmmm
| | | | |
A B C D E
100 110 120 130
This is a common multi-input voltage transformer used in international
equipment, having inputs of 100, 110, 120, 130 Volts. This will typically
be a low voltage transformer, but you really don't care about the secondary
side.

If you typically see from 100 to 130 volts and you want 110 volts, you would
hook up the output to A-C. and the input to:

100V A - B
110V A - C
120V A - D
130V A - E

With this setup, you will boost or decrease the voltage depending on where
you have the input.

You will need to find a transformer large enough to supply your peak
wattage, and remember that even if you normally draw 9A at 110V, in the 100
V boost configuration, your input current will be 9.9A.

Also autotransformers DO NOT isolate the secondary from the line, so
electrical shock is still possible.


"Panama" wrote in message
...
I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

AC voltage adjuster - how to do cheaply
 

On Sun, 23 Nov 2003 16:43:03 -0800, Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

Seems like I answered this in another newsgroup, but if you missed it...

There are two types of auto-regulating transformers. The old kind uses a
swinging core. As the voltage varies, the core moves in and out to provide
a more or less constant voltage. I say "more or less" as they can seldom
act fast enough to block transients, those very short term spikes which can
damage electronic gear.

The second type are called "ferro-resonant" transformers. They work by
driving the core into saturation and operate in parallel with a
non-polarized capacitor to ensure that the output voltage always remains
the same. They offer a few advantages, the best being that they do not
transfer voltage transients (spikes).

Both are rated in volt-amps and both are available on the surplus market.

Good luck
--

Larry
email is rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

On Sun, 23 Nov 2003 16:43:03 -0800, Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

Seems like I answered this in another newsgroup, but if you missed it...

There are two types of auto-regulating transformers. The old kind uses a
swinging core. As the voltage varies, the core moves in and out to provide
a more or less constant voltage. I say "more or less" as they can seldom
act fast enough to block transients, those very short term spikes which can
damage electronic gear.

The second type are called "ferro-resonant" transformers. They work by
driving the core into saturation and operate in parallel with a
non-polarized capacitor to ensure that the output voltage always remains
the same. They offer a few advantages, the best being that they do not
transfer voltage transients (spikes).

Both are rated in volt-amps and both are available on the surplus market.

Good luck
--

Larry
email is rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

On Wed, 26 Nov 2003 14:28:34 GMT, L. M. Rappaport
wrote:


I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.

However, you can have problems when using a ferroresonant tranformer
or charger on a genset or other off-grid power sources, since the
ferroresonant transformer depends on the power frequency being very
close to 60 Hz. If the frequency shifts, the transformer output
voltage will also vary.





--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

AC voltage adjuster - how to do cheaply
 

On Wed, 26 Nov 2003 14:28:34 GMT, L. M. Rappaport
wrote:


I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.

However, you can have problems when using a ferroresonant tranformer
or charger on a genset or other off-grid power sources, since the
ferroresonant transformer depends on the power frequency being very
close to 60 Hz. If the frequency shifts, the transformer output
voltage will also vary.





--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

AC voltage adjuster - how to do cheaply
 

On Sat, 29 Nov 2003 12:02:41 -0800, Peter Bennett
wrote (with possible editing):

On Wed, 26 Nov 2003 14:28:34 GMT, L. M. Rappaport
wrote:


I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.

However, you can have problems when using a ferroresonant tranformer
or charger on a genset or other off-grid power sources, since the
ferroresonant transformer depends on the power frequency being very
close to 60 Hz. If the frequency shifts, the transformer output
voltage will also vary.

I haven't the experience, but you are probably correct. Resonance
would depend upon the "Q" of both the transformer and capacitor.
Another important consideration is that while ferroresonant
transformers might work for charging batteries, since they operate
using square waves (core saturation), they are usually not recommended
for running electronic equipment or anything sensitive to spikes.
Battery charging is ok, however, since the battery acts like a big
sink for spikes.
--

Larry
Email to rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

On Sat, 29 Nov 2003 12:02:41 -0800, Peter Bennett
wrote (with possible editing):

On Wed, 26 Nov 2003 14:28:34 GMT, L. M. Rappaport
wrote:


I think there are two kinds. One type uses a swinging core in the
transformer and works by adjusting the output voltage. The other uses
what is known as a "ferroresonant" transformer which works by
saturating the core at resonance with a non-polarized capacitor which
keeps the output steady regardless of input voltage swings. In a
marine environment, I'd opt for the latter as there are no moving
parts.

However, you can have problems when using a ferroresonant tranformer
or charger on a genset or other off-grid power sources, since the
ferroresonant transformer depends on the power frequency being very
close to 60 Hz. If the frequency shifts, the transformer output
voltage will also vary.

I haven't the experience, but you are probably correct. Resonance
would depend upon the "Q" of both the transformer and capacitor.
Another important consideration is that while ferroresonant
transformers might work for charging batteries, since they operate
using square waves (core saturation), they are usually not recommended
for running electronic equipment or anything sensitive to spikes.
Battery charging is ok, however, since the battery acts like a big
sink for spikes.
--

Larry
Email to rapp at lmr dot com

AC voltage adjuster - how to do cheaply
 

Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

AC voltage adjuster - how to do cheaply
 

Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

AC voltage adjuster - how to do cheaply
 

Terry wrote:

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

Terry writes further.
Transformers tend to be heavy (if this is of any concern on an
average boat?). A 'lighter' way than an auto transformer or
tapped transformer which carries the whole load (which is
apparently of the the order 40 amps x 12 volts = approx. 480
watts; that's about 500 VA) is to use a smaller transformer with
a low voltage output.
For example lets assume a suitable transformer of 120 volts input
with ten volts output. That small transformer is connected in
such a way that it's output 'opposes' the too high voltage coming
from the shore supply; viz. 128 volts minus the approx. ten volts
of the smaller transformer is; 128 - 10 = 118 volts (almost spot
on!).
You have to know what you are doing but it can and has been done.
The small transformer in the example given will only have handle
about 10/120 of the total power = less than one tenth of the
total wattage and can thus be more compact, cheaper and lighter.
But it must be done safely and connected the proper way with
appropriate fusing.
Cheers.

AC voltage adjuster - how to do cheaply
 

Terry wrote:

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

Terry writes further.
Transformers tend to be heavy (if this is of any concern on an
average boat?). A 'lighter' way than an auto transformer or
tapped transformer which carries the whole load (which is
apparently of the the order 40 amps x 12 volts = approx. 480
watts; that's about 500 VA) is to use a smaller transformer with
a low voltage output.
For example lets assume a suitable transformer of 120 volts input
with ten volts output. That small transformer is connected in
such a way that it's output 'opposes' the too high voltage coming
from the shore supply; viz. 128 volts minus the approx. ten volts
of the smaller transformer is; 128 - 10 = 118 volts (almost spot
on!).
You have to know what you are doing but it can and has been done.
The small transformer in the example given will only have handle
about 10/120 of the total power = less than one tenth of the
total wattage and can thus be more compact, cheaper and lighter.
But it must be done safely and connected the proper way with
appropriate fusing.
Cheers.

AC voltage adjuster - how to do cheaply
 

yeh, you're missing something. I pull into marina 1 in town 1 - AC -
105V - charger puts out say 14.3 V - go to marina 2 in town 2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town 3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary from town
to town.


On Sun, 30 Nov 2003 21:33:42 -0330, Terry
wrote:

Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

AC voltage adjuster - how to do cheaply
 

yeh, you're missing something. I pull into marina 1 in town 1 - AC -
105V - charger puts out say 14.3 V - go to marina 2 in town 2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town 3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary from town
to town.


On Sun, 30 Nov 2003 21:33:42 -0330, Terry
wrote:

Panama wrote:

I have a 40 amp battery charger that has a 5 position switch to select
the battery charging voltage. Works great. Allows steps from about
13.2 to 17 volts. Prob done by a multi-tap transformer?

Trouble is - AC voltages in Mexico can be as high as 128-130 VAC and
other places can be as low as 105 VAC. The charger reacts by changing
the battery charging voltage up or down - a little but enough to vary
the DC amps that get to the batteries. I'm not going to replace the
charger.

I'm looking for a cheap variac/scr/triac something gizmo that I can
wire into the AC line to the charger and make the effective voltage
(RMS value?) go up or down by +/- 10% or so. The AC in is about max 9
amps. It could even be a big wired wound variable resistor I suppose.
Then I can set the AC line voltage to what my genset puts out and use
the charger at it's max 40 amps all the time.

Any ideas or products. Preferably cheap and never needs replacement
like the 27 years old charger.

(No I'm really not going to replace the charger.)

The specified/allowed 'Voltage variation' plus/minus varies (pun
intended!) a little from country to country and region to region.
E.g. North America, Europe, etc.
In some places it may be plus and minus ten (10) per cent. In
another area it may be, say, minus 6% to plus 10%. If in Mexico
the voltage is occasionally up to 128/130 on a supply that is
supposed to be 117/120 volts; that's around 9% to 11% high. i.e.
acceptable? If you are monitoring it anyway why worry? Is in
danger of burning out. i so tap it down to the next lower
ampere/voltage output setting?
Or am I missing something?

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
yeh, you're missing something. I pull into marina 1 in town 1 -
AC -
105V - charger puts out say 14.3 V - go to marina 2 in town
2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town
3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V
and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to
the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary
from town
to town.


I think we went through this before. It is not cheap, but take a
look at:

http://www.sola-hevi-duty.com/produc...ning/Index.htm

Leanne

AC voltage adjuster - how to do cheaply
 

"Panama" wrote in message
...
yeh, you're missing something. I pull into marina 1 in town 1 -
AC -
105V - charger puts out say 14.3 V - go to marina 2 in town
2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town
3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V
and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to
the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary
from town
to town.


I think we went through this before. It is not cheap, but take a
look at:

http://www.sola-hevi-duty.com/produc...ning/Index.htm

Leanne

AC voltage adjuster - how to do cheaply
 

On Fri, 05 Dec 2003 22:07:27 -0800, Panama
wrote:

yeh, you're missing something. I pull into marina 1 in town 1 - AC -
105V - charger puts out say 14.3 V - go to marina 2 in town 2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town 3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary from town
to town.

You could use a variable autotransformer (one trade name is "Variac")
- cost US$200 - 300

However, despite your statement that you won't replace the charger, I
would strongly suggest installing a modern charger, such as the
Xantrex TrueCharge 40+ - they're around US$400, and have the advantage
that they are "install and forget" - they'll work from 90 to 135 volts
with no attention on your part, and will be much kinder to your
batteries than your old charger, even if you do remember to adjust the
Variac correctly.



--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

AC voltage adjuster - how to do cheaply
 

On Fri, 05 Dec 2003 22:07:27 -0800, Panama
wrote:

yeh, you're missing something. I pull into marina 1 in town 1 - AC -
105V - charger puts out say 14.3 V - go to marina 2 in town 2 - AC is
114 V - charger puts out 14.4 V - now go to marina 3 in town 3 - AC is
130 V - charger puts out 14.7 V . So my genset puts out 120 V and the
charger does 14.5 V - all the 14 v voltages are regulated but
dependent on AC input voltage - I'd like to adjust the AC to the same
120 V no matter what town/marina I'm in - then I get the same
charging. The AC voltages are constant in each town but vary from town
to town.

You could use a variable autotransformer (one trade name is "Variac")
- cost US$200 - 300

However, despite your statement that you won't replace the charger, I
would strongly suggest installing a modern charger, such as the
Xantrex TrueCharge 40+ - they're around US$400, and have the advantage
that they are "install and forget" - they'll work from 90 to 135 volts
with no attention on your part, and will be much kinder to your
batteries than your old charger, even if you do remember to adjust the
Variac correctly.



--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

AC voltage adjuster - how to do cheaply
 

Let me explain why I won't install a new charger to solve this
irritation - it's not really a problem - a minor irritation.

I have 2 of these chargers - provides 80 amps of capacity and
redundancy (but never needed). They've been in use for 27 years -
since the boat was built - have never failed - never even hiccupped.
Not even the knob or meter has broken. I've had Heart and Trace
inverters (both bought by Xantrex) - fail - repairs cost more than
they were worth to repair. Not really junk - just not really good
stuff.

I've had my present Trojan 6V's for almost 7 years. Still fine. I had
Surette 8D's for 8 years before that. I treat stuff I own to
intellingent maintenance.

I don't need a "set and forget" boat - or items that break every 18
months. And lots of modern "marine" gear is really "marina" gear.



On Sat, 06 Dec 2003 11:42:33 -0800, Peter Bennett
wrote:

On Fri, 05 Dec 2003 22:07:27 -0800, Panama
wrote:


You could use a variable autotransformer (one trade name is "Variac")
- cost US$200 - 300

However, despite your statement that you won't replace the charger, I
would strongly suggest installing a modern charger, such as the
Xantrex TrueCharge 40+ - they're around US$400, and have the advantage
that they are "install and forget" - they'll work from 90 to 135 volts
with no attention on your part, and will be much kinder to your
batteries than your old charger, even if you do remember to adjust the
Variac correctly.