Circuit break controlling two devices at the same time, with same button

Thread Starter

martinsson93

Joined Nov 4, 2021
71
Hi!

I would like some tips regarding how to control power to two of my devices with help from just one circuit break.

One of the devices are a power bank which have one red and one black cable from it (so that shouldn't be so hard) and the other device are an amplifier which gets it's power from the power bank, but also has a on/off button which I would like to remove or somehow also control with the circuit break.

The thing that I want to achieve is that both the power bank and the amplifier will start when I turn the circuit break on and that they'll turn off when I turn the circuit break off. There is already a button for on/off on the amplifier so I guess I'll have to remove that and solder wires to some kind of circuit break instead?

The power bank has 5 V supply.

What kind of circuit break can I use for this?
 

Thread Starter

martinsson93

Joined Nov 4, 2021
71
Connection v.2 .jpg

I'm not completely happy about what switch to use yet. The configuration should be as the image attached. Should I use 4 pins or 6 pins? Or something different?
Like I said before I would like the swith to control both the power coming from the power bank, which is later connected to other things that need the power, and the on/off button on the amplifier.
Can someone help me with how to connect everything in the best way? Thank you!
 

djsfantasi

Joined Apr 11, 2010
8,256
You’ll need a DPDT switch. Maybe, I’ll explain later.

The common contacts of the switch will connect to the power bank.

One set of contacts will connect to just the amplifier. The second set connects to all devices (including the amplifier) with one detail. You’ll need a diode between the positive lead and the amplifier, to prevent back feeding when only the amplifier is selected. Assuming the amplifier can operate with a 0.2 to 0.7 voltage drop due to the diode you select.

Secondly, you likely only need a SPDT switch and just connect all the devices to a common ground.

And lastly, a SPDT center-off switch will give you a power off option.
 

Thread Starter

martinsson93

Joined Nov 4, 2021
71
Thank you for your reply @djsfantasi!

I'm still a bit confused since you mension 3 different types that might work. Which one do you think would be best to try with?
I'm not sure that the amplifier can operate with a drop in voltage.

I have to be able to turn everything off with the swith and then turn everything on with "the other side" off the switch.
So there only have to be two options, either everything is off or everything is on.

I already bought a DPST but later realised it didn't work at all how I thought it would.
Thank you!
 

djsfantasi

Joined Apr 11, 2010
8,256
I'm still a bit confused since you mension 3 different types that might work. Which one do you think would be best to try with?
I have to be able to turn everything off with the swith and then turn everything on with "the other side" off the switch.
I just re-read your question. Seems I misunderstood the problem. I thought you wanted to switch either one device or that device plus the amplifier. That being said, all of these options aren’t correct. [/QUOTE]

I already bought a DPST but later realised it didn't work at all how I thought it would.
Not sure why, because that should have worked. Perhaps you wired it to the wrong terminals. Two of them make a simple SPST switch. The other two makes another. The other contacts should not show any connectivity.

One thing that is not clear is the power requirements of the amplifier. What voltage does it require? And what’s the current requirements? These hold for your other device(s) too.

When choosing a switch, there are three parameters which need to be matched to its use. Is the power AC or DC? What is its curreht rating. And the type, SPST, DPST, DPDT, etc..
 

Thread Starter

martinsson93

Joined Nov 4, 2021
71
Okay I see. Thank you for taking your time.

The thing is that I'm not sure how to connect the wires to the DPST switch. Would you mind draw for me how to connect everything to the 4 pins?
The DPST that I have, have a LED which requires 12 V, which I realised that I don't have since my power supply is 5 V. So maybe the switching function would work if I connect it correctly, but that the light won't be on?

The amplifier requires 5V, not sure about the current requirements, but I know that it works with the power supply that I have. The other devices also needs 5V. The power from the power bank is DC.
Thank you once again! I really apprechiate it!
 

djsfantasi

Joined Apr 11, 2010
8,256
It’s hard to tell. That’s not a proper schematic so difficult to read.

With your additional clarification. You don’t need a complex switch. A SPST or simple on/off switch is all that’s necessary. I’ll draw it out later when I get home (celebrating Christmas with my daughter’s family now). My point earlier about using a common ground DOES apply now that I know everything is powered by 5V

I’m also assuming that the amplifier has some sort of jack for its power… Am I correct?

Also, with respect to the existing switch, you can leave it alone. Just don’t use it. Tape it closed if necessary. Or assuming that it only has two wires and two terminals going to it, you could solder a wire jumper between the terminals. The switch would still be there but would be incapable of doing anything.

Don’t fret about this, but since you only need a SPST switch, an SPST, DPST, SPDT, DPDT, or almost ANY switch would work. If you learned the standard symbols used for a proper electronics schematic, you’d see quickly why I said this. So don’t go out and buy any more switches. You have what you need!

There is a page on AllAboutCircuits which shows the symbols used in schematics for (manual) switches. Not the symbol for an SPST and then note that you can find the components of that symbol in all of the other (except push button or momentary) switch symbols.

That’s all I can say for now. I’ll get back to you in a few hours.

Do your homework and we’ll chat later!
 

Thread Starter

martinsson93

Joined Nov 4, 2021
71
It feels like a simple thing, but I can't figure it out, it's how to wire everything to the 4 pins that I find hard. But everything is hard when you do it for the first time I guess. Thank you for being my teacher!

This is the switch that I have FYI: https://se.rs-online.com/web/p/rocker-switches/4685380

I can solder a jump wire for the on/off button on the amplifier, that's a good point!
And yes, the amplifier has a jack for the 5 V power.

I've read the page and are going to read a little bit more, doing my homework while I'm waiting for you reply.
Have a good christmas!
 

Thread Starter

martinsson93

Joined Nov 4, 2021
71
Thank you!

I understand your image, but I feel so stupid because I don't understand how to connect the wires to the pins on the switch? Am I only going to use two of them? Not all four?
 
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