Newby needs help with switching

Thread Starter

SteveB2108

Joined Jun 10, 2009
3
Hi, I hope I don't appear too dumb but I can't work out a solution to this (simple) problem.

What I have is a mini 433MHz transmitter that I want to install in a panic button box. The panic button is a latching button (press in to turn on and twist to turn off) but the transmitter requires a momentary voltage to send a "turn me on" signal to the transmitter and a separate momentary voltage (on another pin) to send a "turn me off" signal to the transmitter when the latching button is released. So, there are 3 pins on the transmitter. One is common.

I plan to use a 9V battery as the power source. The 433MHz transmitter will work betweeen 3v and 12v. Preferably I want to avoid draining the battery if the latching switch is left on.

Any help with this design would be most appreciated. I am new to electronics so the more detail the better.:)

Thanks
 

hobbyist

Joined Aug 10, 2008
892
A oneshot multivibrator circuit, one for each of the 2 input pins, could be used.

If the panic switch is a single pole double throw type.
 

Bernard

Joined Aug 7, 2008
5,784
Mostly speculation: Switch A,B,C; AC normally closed, when pressed mechanically latches to AB, in closing sends a +, 1ms pulse[ depending on input Z of transmitter] to ON transm. When switch is releaced, a pulse is sent to OFF transm. If momentary = 1ms, might work. To disable transm. if switch is not released the lower ckt added. Time delay, R5-C willcause a +pulse ORd with origional OFF pulse to shut off transm. When C charges to zenor diode break down V , sensitive gate SCR 2N5060 is triggered, The charge on C is dumped across R7,R8,& R9, giving a + pulse to transm.R5 should be as large as possible but still able to trigger SCR, as the delay cycle will continue untill SW is resft, battery drain is then R2 in parallel with R5 for a leak of around 5μA. It's a start at least.
Some possible values: R1,R4, R8,R9 100k; R5 1-2M; R6 2X R5; R7 220Ω; C, about 1 μF/sec.[ 10μF ]., diodes 1N914 etc., un-labled cap another .01. R2,RR3 10M.
 

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koen

Joined Jun 10, 2009
1
Gibberish removed by moderator.

Strongly suggested that the OP make replies in a more acceptable fashion.
 
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Thread Starter

SteveB2108

Joined Jun 10, 2009
3
Bernard said "To disable transm. if switch is not released the lower ckt added."

I am not sure I understand the 2nd circuit. The 1st one seems simple enough but what would happen if the switch is not released?

If the 2nd circuit is used, how does it connect to the switch?

Thanks for the help.
 

Bernard

Joined Aug 7, 2008
5,784
We need to know what the panic button looks like electronically. how does it deliver pulses to the transmitter, then maybe we can find a solution for the latch I was just speculatong on what it might look like.
 
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