"Roger Long" wrote in news:46b66da5$0$8977
:

http://home.maine.rr.com/rlma/MOB.htm

"I also found this nifty little light. Press or hold the switch and it
strobes. Press it again and it can be used as a steady flashlight. Twelve
bucks. The tiny little module (see insert) will weigh almost nothing on
the pole and is all ready to be wired to batteries in the bottom and a
switch. The light module weights less than the quarter next to it and is
bright enough to light up a room."

I copied this paragraph from your webpage......

Notice how you have to HOLD the switch CLOSED to get it to go into
strobing mode? What happens when the switch gets a little old and
holding it down results in a noisy connection is the IC keeps seeing
intermittent presses, not a steady-state hold down for X seconds. One
little intermittent interruption when your finger moves is enough to
reset the timer that's trying to time down into strobe mode. It's a
stupid design with such cheap switches.

Clip a jumper wire across the reed switch and see if it doesn't start
strobing reliably. If so, it's the reed, even though it will read fine
on an ohmmeter which cannot see the pulsing probably going on.

I bought a whole bunch of these little 3 really bright yellow LED
"Emergency Flashers" from a flea market dealer. He wanted $1 each, but
sold me the whole box for $10, what was left. I've given all of them
away except what I wanted to keep. The button in it is unreliable in
this same way. It's a rubber switch pressing on the circuit board pads.
Its sequence is a little different than yours. One press gets a "steady
on" light, which is an optical illusion because the LEDs are actually
switching on and off at a very fast rate, 50% duty cycle, to save
batteries. Press it again and the flash rate goes to about 2 per second
at full power. Press it again and SOMETIMES the damned things will turn
off....SOMETIMES...(c;

The correct term for your observation is called "contact bounce" and has
plagued data engineers since before ICs were invented. Most ICs that are
forced to interface with humans have a timer circuit at each interface
point that takes input, then refuses to take more input until the timer
has timed out, several milliseconds, to keep the cheap, noisy switch from
giving it 500 button pushes with each finger push. It's called a
"debouncer", obviously. Your little light's debouncer isn't timed long
enough, now that the switch is crap.

ICs are way too fast for their own good....(c;



Larry
--
Democrats are raising taxes on oil companies by $16,000,000,000.
Oil companies don't pay taxes, just like every other company.
Consumers pay all taxes, corporate and individual.
What's the price of a gallon of regular going to go to to pay $16B more?