vic wilkinson wrote in
:

to manufacture isolators they must be ce approved & pass many
application tests. They must be able to withstand dc currents (not just
ac currents) & must have heatsinks capable of withstanding high
temperatures for prolonged time (not milliseconds as you state!)


The European Union's Electromagnetic Compatibility (EMC) Directive
89/336/EEC outlines the requirements for electrical apparatus to control
interference by establishing 'essential requirements' for all electrical
goods.
"The electrical apparatus shall be so constructed that:
a) The electromagnetic disturbance it generates does not exceed a
level allowing radio and telecommunications equipment and other apparatus
to operate as intended.
b) The apparatus has an adequate level of intrinsic immunity to
electromagnetic disturbance enabling the device to operate as intended."

The European Union's harmonized EMC Standards provide guidelines and limits
for testing and include descriptions of test layout and methods, as well as
defined maximum permissible limits of electro-magnetic emission and
immunity levels.

Shouldn't be a problem getting 4 diodes to pass an EMC test that don't
conduct in normal use, eh?

50A not enough DC current? It's a RECTIFIER, after all... There's a 100A
version for a few bucks more. Let's face it, your product is just 4 diodes
on a heatsink. I'd bet my $8 bridge on a heat sink makes the same heat as
your 4 diodes on a heatsink. The bridge is made for 50A continuous DC
current (or 100A if you insist we use the bigger bridge). It will still
cost under $15 with a big heat sink if we leave out the "marine" logo
stickers.

The 50A bridge on our boat has tripped many a breaker using the aluminum
breaker panel as a heat sink with some heat sink compound between them. It
hardly gets warm. I'll send UL a shorted bridge rectifier to see if I can
get it certified for USA.

Where's all this DC current coming from, just for information? God, I
can't imagine what 50A DC to the marina ground can do to your boat if all
this DC current were flowing for more than a few minutes. It'd eat the
prop right off the shaft!

"Larry W4CSC" wrote in message
...
vic wilkinson wrote in
:

to manufacture isolators they must be ce approved & pass many
application tests. They must be able to withstand dc currents (not just
ac currents) & must have heatsinks capable of withstanding high
temperatures for prolonged time (not milliseconds as you state!)


The European Union's Electromagnetic Compatibility (EMC) Directive
89/336/EEC outlines the requirements for electrical apparatus to control
interference by establishing 'essential requirements' for all electrical
goods.

snip

Shouldn't be a problem getting 4 diodes to pass an EMC test that don't
conduct in normal use, eh?

The EMC part is not the problem, you are allowed to test that yourself, if
you have the equipment. But since this device is part of the mains circuit,
other tests will have to be conducted which you are not allowed to do
yourself, you have to hire a notified body for that. And that costs.

Meindert