Momentary Startup/Shutdown Controller

SiGmA_X · 10-08-2003, 07:43 PM

I am looking for a controller to give power to my inverter when toggled via a momentary switch, not a toggle switch. The reason for wanting a momentary is so I can use momentary switches on the dash as well as the accessory ‘switch’ (Which is momentary) on my car alarm. Is there some sort of simple circuit that will allow power to run and be killed based on momentary switches? Or could someone help me make one? I can do all the soldering and whatnot, but I don’t know much about what parts to use

Thanks.

Ricky327 · 10-09-2003, 10:38 PM

I dont know how much you know about electronics but you can design one using a D-type flip-flop wired up for your needs. A typical D-type is the TTL 74LS74, theres 2 in a package, +5V supply.

The input is the "CLK" connected to your momentary switch. The output "not Q" is fed back to input "D". You can take any output "Q" or "not Q". The output changes when a transition is made from Low-High from your switch. Wire up your switch with a pull-down resistor such as it provide a "high" when pressed. You also need to clean the spikes from the switch by adding a debouncer, just a small capacitor.

Thats it, hope that helps

SiGmA_X · 10-09-2003, 10:55 PM

I could prob wire it. I'll stop by an electronics parts wearhouse this weekend to see what they have for it

Thanks!

bgoodman · 10-09-2003, 11:09 PM

http://aaroncake.net/circuits/touch.htm ?

SiGmA_X · 10-09-2003, 11:46 PM

Thats what I need

But can it use +12V instead of +9V input? :-\

Ricky327 · 10-09-2003, 11:56 PM

Yup, CMOS can take 15 Volts. Just be careful with them they can get damaged easily by statics.

http://www.fairchildsemi.com/ds/CD/CD4011BC.pdf

You need to modify the input so that it take "voltage" rather than "touch"

I dont think thats the circuit you are looking for. What it does is provide a "pulse" for a second when the pads are touched, it doesnt stay "Low" or stay "High". From what you said you needed a "toggle" type switch triggered by a momentary push button switch.

SiGmA_X · 10-10-2003, 12:33 AM

What you said in the last part From what you said you needed a "toggle" type switch triggered by a momentary push button switch is what I need! Any ideas? That is fully what I need!

Ricky327 · 10-10-2003, 12:51 AM

http://www.doctronics.co.uk/4013.htm

Thats a CMOS version of the D type flip-flop. As on my post #2, I mentioned how it can be connected as a toggle flip-flop. Just connect your debounced switch at the "CLK". S and R can be tied to 0V.