What is the name of this switch type?

[John61CT]

Like a rear-window defrost button: push once ON, push again OFF

If left ON when upstream power is cut, then next time that power returns the switch state always reverts to (starts out as) OFF.

Besides the terminology for googling, links to some examples would be great.

More generally, if anyone can recommend a good quality, inexpensive online source (most importantly with a comprehensive range) of switch types, I'd greatly appreciate it.

I want to be able to create a customized 12V distribution panel, with all my load switches in one spot. Ideally with a unified design, not looking hodge-podge.

An Aussie example of the general idea: http://www.dukes4x4andcamping.com/panels

 

[Trebor English]

It is an input to the computer.  The computer sees when you push, momentary contact.  The front computer tells the back computer to turn on or off the heat.  The light in the switch or guage cluster is controlled by the front computer.

That's the way it works on my 1999 Ford Windstar.

 

[Optimistic Paranoid]

I think the key word here is "latching".  You are looking for a SPST Push On Push Off latching switch.  Not all that common, most push button switches are momentary on.

 

[John61CT]

It is an input to the computer.

Well that's not good
Hope I can find a mechanical way.

I think the key word here is "latching".  You are looking for a SPST Push On Push Off latching switch.  Not all that common, most push button switches are momentary on.

But I want the State to revert to OFF when the switch is powered down.

I think Latching means no power keeps the state whatever it was.

 

[Trebor English]

You could get a similar result easily.  Could you go for two push buttons, one for on, one for off?  Use a relay.  Have the coil supplied from the relay switch.  It will revert to off with no power.  Have a normally off momentary on push button also apply 12 volts to the coil.  Push the button to turn it on.  Once it comes on the relay's switch will hold it on.  To turn it off have the second switch be normally on momentary off in series with the coil.  When you push the off button the relay coil current stops, the relay switch opens and it is off.  You wanted one push button with revert to off.  This gives revert to off.  The holding current in the relay could be low with a small relay.  A trick to reduce the current is to put a resistor in the coil power circuit when powered by the relay switch but full 12 volts from the push button.  Relays require less current to hold, more current to pull in the moving switch part, maybe half

 

[John61CT]

Well yes, for one view of the word "easy"

In fact just the ON would be OK, off could just be the (upstream) power getting cut.

 

[DannyB1954]

On mobile Reefers we used to use a momentary contact switch to toggle a relay. The switch gives momentary power to move the 2 terminal relay. Once energized, the relay gets power to stay energized through the second set of contacts inside the relay. When that circuit either loses power or a ground, the relay flips back and will not re energize on it's own.
Not hard to do. You can power the second set of contacts through an accessory terminal, so when you shut off the vehicle, the relay will drop out. You would need a second nc momentary switch in the relay coil circuit if you wanted to shut down the circuit without turning off the vehicle.

 

[DannyB1954]

The reason we used a two contact relay was because a smaller fuse could be used to protect the coil circuit, And a larger fuse to protect the load.

 

[DLTooley]

Household switches are cheap and as being designed for 120v bombproof at 12v. I would use a 12v fuse block.

 

[Zizzer_Zazzer_Zuz]

Household switches are cheap and as being designed for 120v bombproof at 12v. I would use a 12v fuse block.

I was wondering about that. Can you just use a wall switch wired to DC? + to + and - to - and done or is there more to it?

Here's another question. I have a switch plate with a switch and a wall socket outlet. Can you wire this to turn on and off the power outlet? For instance I have a rice cooker that you must unplug from AC when it's done cooking. Could I wire AC from my inverter to the switch, then to the outlet so that when the rice is done cooking I can just use the switch to cut juice to the rice cooker?

What about wall switches for running DC LED lights?

I can get light switches at my local Habitat Restore for dirt.

 

[highdesertranger]

Z it depends, the switch must be rated for the load of the rice cooker or the largest load you might ever plug into the socket. highdesertranger

 

[Trebor English]

Switches typically have different current ratings for DC and AC.  The DC rating is lower.  An AC circuit actually turns off 120 times per second in US and Canada, 100 in the rest of the world.

 

[DannyB1954]

I was wondering about that. Can you just use a wall switch wired to DC? + to + and - to - and done or is there more to it?

Here's another question. I have a switch plate with a switch and a wall socket outlet. Can you wire this to turn on and off the power outlet? For instance I have a rice cooker that you must unplug from AC when it's done cooking. Could I wire AC from my inverter to the switch, then to the outlet so that when the rice is done cooking I can just use the switch to cut juice to the rice cooker?

What about wall switches for running DC LED lights?

I can get light switches at my local Habitat Restore for dirt.

On DC circuits that use high current only use switches rated for DC.  The ac switch would have a tendency to arc across the contacts more than the DC switch when turning off under a load. 

You can use an AC switch on an AC circuit. The output of the inverter is ac.  So no problem using the switched outlet. 

The LED lights use such low current that I don't think arcing is an issue.

 

[DLTooley]

Make sure you don't confuse yourself and connect 120v ac to your 12v circuit!

 

[tx2sturgis]

You CAN use a standard household lightswitch for controlling a DC circuit, but its not the best solution. 

You should de-rate the current ratings, and realize it may go intermittent sooner or later, since cheap and especially used/reclaimed switches may be nearing end-of-life, and most do not have self-wiping contacts.

 

[MrNoodly]

Any of these?

https://www.mcmaster.com/#standard-push-button-pilot-switches/=180ltq7

 

[tx2sturgis]

Like a rear-window defrost button: push once ON, push again OFF

If left ON when upstream power is cut, then next time that power returns the switch state always reverts to (starts out as) OFF.

What you are looking for is called 'soft-latching' and most of those require some type of either a relay or a solid state controller circuit...

I found a few items googling around but I dont really know what you are trying to control, or how many you might need.

If you need a bank of them, you might want to look into a micro computer like an arduino or similar. Those things are full of possibilities but are beyond my experience so you would need to so some research to know if one or several might work for you.