• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

help! need to modify a bistable flip-flop circuit....

Status
Not open for further replies.

xxplorer

New Member
I am working on a special project that requires a circuit that does the following:

1) activated by a single momentary switch

2) causes a 12v light to turn on when initially pressed and stay on, until pressed again, to turn it off (need a +12v output), until pressed again

3) each time the switch is pressed, also provide a momentary ground signal to a device.

ie press button, light goes on & momentary -12v pulse, wait until button pressed again, turn light off & pulse again a momentary -12v pulse, wait for next button push

4) add a DIP switch or option jumper that will allow the circuit (when power is initially supplied) to simulate pushing the button once (or not) (causing the light to go on and give a momentary -12v pulse).

Any help will be greatly appreciated. I am a hobbyist with minimal design experience, but i can build a circuit and solder.

I found a bistable flip-flop circuit that might seem to work, but i was wondering if anyone had a better idea.

the light is 2.5w 12 volt. the momentary pulse should be about 1 sec in duration.

thank you in advance for ANY help.

ps the circuit i found was below, on the left, to accomplish the light on/off. however, there are other circuits i know i could use. can anyone help?

thanks

 

xxplorer

New Member
followup

i built the circuit as is on the left. i am having several issues:

#1) when energized (before the button is pressed, but when connected to the 12 v supply), the light sometimes turns on before the button is pressed, so that when the button is pressed, it turns off instead of on.

how can i make it so that each and every time the +12v source is applied to the circuit, that the light stays off until the button is pressed the first time ( or after some delay, a circuit simulates pressing the button, causing the light to turn on and providing a momentary pulse)?

would a MOSFET toggle switch solve some if not all the problems (ie initial state off, etc.)?

thanks
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top