Hi, am trying to design ON/OFF switching circuit using the same push-button,

[nyame]

Hi, am trying to design ON/OFF switching circuit using the same push-button, i tried using the circuit attached below but it does not work, will appreciate any help. thanks

[Vtile]

magic search word is "TOGGLE".

[Wimberleytech]

Hi, am trying to design ON/OFF switching circuit using the same push-button, i tried using the circuit attached below but it does not work, will appreciate any help. thanks

A D flip flop with Qbar tied to D.  Resistor pullup on clock. Push button from clock to ground.  To address switch bounce, RC delay from Qbar to D.

[tautech]

First 'toggle switch 555' hit on Google:
http://www.zen22142.zen.co.uk/Circuits/Switching/555toggle.htm

[malagas_on_fire]

 What about a transistored one?

http://danyk.cz/zap-vyp_en.html

[MarkF]

[spec]

UPDATE#1  2018_12_05 (simpler circuit)

Hi nyame

The 555 timer is a good chip but it is not really suitable for some applications. As a result of this, the other members have given simpler and better circuits. But if you must use a 555, attached is schematic for a 555 toggle circuit for you.

When the circuit first powers on, the output will be set to 0V, and the LED will be off. The first time you press and release the switch, the 555 will toggle and the LED will illuminate. The next press and release and the 555 will toggle again and the LED will go out...and so on.

The circuit has built-in switch denouncing so you will not get multiple toggles each time you press and release the switch.

If you press and hold the switch the 555 will oscillate. C3 defines the switch denounce inhibit. C3 also defines the frequency of oscillation when the switch is held on. You can experiment with different values of C3 to tune the circuit to your liking.

Notice that the 555  Q output is not involved in the toggle function, so the Q output can be used as you wish.

For a low current, low voltage role like this, the switch should have gold contacts, or other contact material suitable for low level signal switching.

[spec]

What about a transistored one?

http://danyk.cz/zap-vyp_en.html

This is a clever circuit: so simple. I didn't realise at first that it automatically powers up in the off state and caters for switch bounce.

If you hold the switch on, I think this circuit will oscillate too.

[Zero999]

Here's a version which includes a timer and can be connected in series with the load.  It's not possible to make this circuit with an indefinite on time, as C3 keeps Tr1 on and there's a limit to how much charge it can hold.