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need circuit to convert from constant to momentary contact on "off" and "on"

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waynedude

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Hi! I have a situation where I have a light dimmer that operates with two momentary contact switches. Each switch has two functions based on how long they are engaged. Tap function, and hold function.
Tap the top switch and the dimmer fades to on. Tap the bottom switch and the dimmer fades to off. Holding either of those switches goes into the second mode, dimming or brightening the light.

I am trying to create a circuit using a standard 120V switch, which will only trigger the tap function. (actually using an astronomical timer, but that has no bearing on the circuit). In other words, feed in a constant 120V, and it will result in a momentary contact of the "ON" microswitch (turning the dimmer on). When the switch is turned off, removing the 120V, the "OFF" microswitch will get a momentary contact.

So a constant on input will trigger an impulse ON contact, and turning that constant input off will trigger an impulse on another contact, resulting in the light turning off.

If you are wondering why I am going through all this, instead of just using the switch to turn the light on and off; The dimmer is actually an RF transmitter. Triggering the on on the transmitter, is the same as if you tapped the paddle on the remote dimmer to on. Same for the off function. I am using an intermatic astronomical timer to remotely turn on the dimmer at dusk, and turn it off at a preset time. The timer will not effect the manual operation of the dimmer, or the pre-set brightness. It can also be programmed to turn on a number of dimmers throughout the house (just by linking the remote to multiple dimmers).

I anybody can help with a simple relay based circuit that could trigger this response, it would be greatly appreciated! Thanks in advance! :)
 

waynedude

New Member
Hmm, Thanks guys. The idea of a time delay relay set would work fine, but cost a fortune (relatively, as they are around $58 each and would require 2).

The second response looks like it would work as the logic circuit if it drove a couple relays. In actuality, I could achieve the on and off pulse and simplify by just driving two short timer circuits on either side of a SPDT relay (powering each circuit on either on or off of the coil). I was thinking of a capacitor and resister in parallel put in series with a relay coil as the timer circuit. I could just duplicate this on both sides of the primary relay contacts. It would require a line voltage relay, and a couple of low voltage relays, capacitors, resisters and a power supply.

Let me know what you think of this idea..
 
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