I am new here. I know a good deal about regular voltage circuits, but little about electronic circuits. I need some of you electronic nerds out there to help me out. Here's what I am trying to do and the answer will be simple to you, so I'd appreciate it if you could give me some insight: I have a power circuit - 24 volts a/c. This circuit is not always energized, but only periodically. In the power circuit is a normally closed swiitch that opens periodically. The switch is before the load. What I need to know or create is a side circuit that bridges the switch. When the switch opens the side circucit would receive the 24 volt power. I need for this event to be counted on a small LCD or electromechanical totalizer or some other electronic combo that only you know about. It needs to be only 3 digits and resettable. It needs to be able to take temperatures of 20 - 120 degrees F. It will not be exposed to moisture, except humidity. The size needs to be no larger than a pack or two of cigerettes. It must be inexpensive and fairly resistant to minor vibration. What set up do I need to accomplish this task? I am thanking you in advance for your help! Thanks, Mike
detection / counter circuit
Oct 28, 2006
2 Replies
How often would this be activiated? You can use this to charge a couple of batteries to power a micro with a LCD counter.
This should work:
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This is what your description sounds like:
| 24 VAC --------------o | o---------------+ ----- | NC Switch * | LOAD | 24 VAC Return ---------------------------+
- (when you push the button, it breaks the circuit)
And what you want is, when the switch is switched, you want your counter to increment.
That's not hard at all - get a "double-throw" switch - when it's in position 1, it connects terminal C to A, and when it's in position 2, it connectes terminal C to B. ("C" stands for "common".) So,
SPDT Sw. o---------------+ 24 VAC --------------o / | o---+ | | | COUNTER | | LOAD | | 24 VAC Return --------------+-----------+
There are mechanical counters that are activated by solenoids - it shouldn't take too much googling to come up with something.
Good Luck! Rich
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