It seems to me you should fugettaboutit re. the relay. Make sure the input signal lead to the counter is debounced - then it will respond to only the first excursion of the "bounce" envelope no matter where it comes from. Also, probabl'd be a good idea to check bypass caps on distribution leads within the counter.
Debounce relay for counter
Apr 11, 2007
23 Replies
I know, it was just the first that came to mind...been a while, if I need a value for a component, I look at the package, it's faster than figuring it out.
the simplest way is to either use a monostable vibrator circuit set to about
I agree. An RC like this might work better, and it's pretty simple to try:
100K ___ to COUNTER TO CONTACT o-|___|---+---------o | --- --- 0.1uF | | === GNDThis is based on some assumptions about what is inside the counter. If it doesn't count reliably, you may have to reduce the 100K.
OTOH, here's a simple circu\it that should do the trick and will operate for a very long time from a battery (shelf life, almost): and will operate up to one operation every couple of seconds. If you need to go faster, reduce the 0.1uF proportionally.
(view with fixed-width font such as Courier)
VCC + | .-. +--------- 100 | | | | | | | | + '-' | ### 100uF/10V +---------------+ --- | | | .-. | === 1M | | | GND | | | '-' 1M | CONTACT | ___ |\ ___ o--------+--|___|--+----| >O- -|___|-o TO COUNTER | | |/ | o --- | 1K |=|> --- | | o 0.1uF | === 1/6 74HC14 or 1/4 4093 | | GND | === === GND GND
For Vcc up to about 5V-6V, you can use a 74HC14:
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For higher Vcc, you can use a 4093 (connect A/B inputs together)
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Ground all unused *inputs*, leave all unused outputs open. Use a similar Vcc to the counter itself (or even the same battery if you can tap into it).
The main issue with this sort of circuit is that it doesn't put much current through the contacts, but if they're bashing into each other enough it won't matter. This is also the case with the battery powered counter itself.
You *could* use something like a single gate in this package (rather than a DIP) and avoid 'wasting' the extra gates, but it might get a little hairy soldering to the 'pins' (those are mm, not inches) Hey, GD&T.
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Best regards,
Best regards, Spehro Pefhany
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