Looking for an IC component. Toggle switch with momentary on and off buttons.

Thread Starter

B25Mitch

Joined Mar 13, 2015
2
I'm not sure if this even exists, but I'd love to find it, preferably as an integrated circuit, as small as possible.

A switch that connects or interrupts a separate circuit, controlled by 2 dedicated buttons, 'on' and 'off', both momentary, but once pressed, the connection maintains state. IE: you push the 'on' button, the circuit stays connected until you press the 'off' button. Load through the chip will be minimal, just enough to trigger a separate transistor.

Attached is my wonderful MS Paint diagram of what I'm looking for.
 

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#12

Joined Nov 30, 2010
18,210
There are many ways known to do this. Most of them use a single button. One standard chip is called a flip-flop. Do you really want 2 buttons or did you just assume you would need two buttons?
 

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Marcus2012

Joined Feb 22, 2015
390
Hi

A 555 Bistable setup would do this well if I understand you correctly. Here is a guide with the switches you describe, the 555 output can then be connected to a transistor used to switch your control circuit of whatever device you wish. The 555 will maintain an output pulse from when one switch is momentarily pressed until a reset switch is momentarily pressed.

555 Timer operating modes Go down to Bistable

555 Timer IC
 

Reloadron

Joined Jan 15, 2015
5,667
I drew another diagram better illustrating my design. I need multiple of these chips, each with their own ON button, but a communal OFF button to reset them all to off.
There are a number of ways to go about this. Since I haven't a clue what you are switching I'll give you a generic suggestion. I would go to the store and buy a pile of D Flip Flops. They can be for example CD4013 or any of a few others. In the store you find them between the carrots and tomatoes. The CD4013 I mentioned has two D flip flops per chip. So if you want ten you use 5 chips. Each flip flop is triggered On with a single clock pulse which can be from a simple push button switch. All the resets are tied so a single reset button will reset (turn off) all of the flip flop outputs. There is not much need for any external components depending on what you want to turn On and Off. If you want a circuit I'll come up with one, there isn't much to it really.

Also the 555 in a bistable mode is another viable option and would likely take the same space as using D flip flops. I would just string out a pile of 556 (dual 555 chips). They can be had in the potato section of the store.

Again, you need to describe in some detail exactly what your goal is with this.

Ron
 

absf

Joined Dec 29, 2010
1,948
If you're able to get 74xx279 quad RS flip flop, here's a simple circuit that will give you 4 outputs with a common reset button. RL1 to RL4 can be relays or LEDs for light current use. If you need more current replace the transistors with logic level MOSFETs.

Allen
toggle sw with on_off button.PNG
 

Roderick Young

Joined Feb 22, 2015
408
This will seem like overkill, but you might consider using a PICAXE 08M2 (about $3). It's an 8-pin DIP, and needs only two external resistors, no external timing components, no external pullups, and touchpad sensors are built-in if you want them, meaning you might not even need switches. If you go that route, then the behavior becomes a matter of software. Not only could you implement the ON/OFF scheme you mentioned, you could even have it turn off automatically in an hour if there is no activity, or turn on only when you tap out "We Will Rock You" on the buttons and turn off only when both are held down for 4 seconds.
 

shortbus

Joined Sep 30, 2009
8,042
It can also be done with a CD4066 or 74HC4066 chip. Doing it with one momentary on button and one momentary off button that is, no flip flop needed. By connecting the 4066 like a 'latching relay'.
 

crutschow

Joined Mar 14, 2008
25,632
I want the next button pressed to turn off or reset the last button pressed.
You should start a new thread for your question instead of reviving this old thread.

That's commonly called a Radio Push-button Circuit.
The buttons can be pushed in any sequence with only the last button pressed becoming active.

Below is the LTspice simulation of such a circuit using NAND gate latches.

1571671538097.png

And here's one using an octal D-Flipflop IC:
(The output LEDs are optional).

1571672224924.png
 
Last edited:

ericgibbs

Joined Jan 29, 2010
11,073
hi @crutschow
I tried to Create a New Thread for this TS, but at the moment I do not have that feature.
As soon as this is corrected, I will Create a new Thread and attach your post# 12.

Eric
 
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