Which relay for a button?
Hello, I would like to install a starry sky projector in my car, which I control via a button that leads to a relay, which then controls the projector. What kind of relay do I need?
The button should open the relay with one click and close it with another (on / off).
I saw there are several variants? Thanks in advance.
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Well, with 12V you can actually leave out the relay and just use a switch.
A "latching button" like that.
Lg
This is really the best solution.
With relays you need two buttons, one for on, the other for off.
There are also impulse relays for 12V control voltage.
Yes, the self-retaining mechanism would have to be reactivated somehow. There are probably solutions for that by now, though. I've been out of the loop for a while now.
Yes, that's what I meant
As soon as I'm sitting at my PC, I create a circuit diagram. It's difficult to do this on a smartphone.
The other way around: the button holds the relay (as in the drawing). Why should you bridge a switch (button)?
The "on" button is bridged by a holding contact of the relay. The "open" button is connected in series with it. It opens when pressed.
In a car, you can also link it to the ignition. Ignition off = relay without power = off.
Yes, it's self-locking . Otherwise, the relay would immediately drop out after releasing the first button.
One button to close, the other to open (interrupt the supply)
If you only have one button, you must use a latching switch ("Eltako").
Of course it must have 12 V control voltage.
But why use multiple components when a normal switch is sufficient?
The button would be original and even have an OEM-matching slot. What about a step-by-step relay?
My answer.
Relays are used when the voltage to be switched (eg, 230V~) needs to be switched from a location that allows contact. This location could be the bathtub.
That probably isn't the case for your application. The 12V of a car battery is safe.
Relays are used when the current to be switched is very high and a simple switch isn't suitable. The length of the wires to a switch also plays a role. A starry sky projector shouldn't require currents exceeding 10A (which would be 120W at 12V).
I've made a design for you. When S1 is activated, the relay is energized. The holding contact continues to supply voltage even when S1 is opened again. As soon as S2 is pressed, the current flow through the relay winding is interrupted, and the relay opens.
But that is just the function of a simple toggle switch.