Question from a newbie about switches

General project discussion / help
Did you make a robotic coffee pot which implements HTCPCP and decafs unauthorized users? Show it off here!

Moderator: phalanx

Post Reply
SysProg
Posts: 2
Joined: Thu Nov 09, 2017 4:25 pm

Question from a newbie about switches

Post by SysProg » Thu Nov 09, 2017 4:31 pm

I am working on a project to add a police lightbar and other lights to a military humvee for my local Police Department to use in inclement weather. The humvee is 24V system with 2 large 12V batteries in series. Some of the equipment is 12V and some is 24V. To prevent draining the batteries I would like to install one master switch that will disable all of the added gear when in the open position and control two circuits, one 12V and one 24V. So, when in closed position the 12V and 24V equipment will have power to them.

What type of switch do I need to buy? I would prefer a toggle switch with a built in LED.


Harley

User avatar
DanV
Posts: 376
Joined: Sat Apr 25, 2015 9:29 am

Re: Question from a newbie about switches

Post by DanV » Fri Nov 10, 2017 7:50 am

You need a DPST - double pole (one pole for 12VDC and one pole for 24VDC) single throw (meaning you can connect or not connect) lighted rocker switch.
You can also use DPDT - double pole double throw - meaning that you can connect your pole to one circuit when the switch is switched one way and connect to a different circuit when switched to the other way.

Amazon has at least one:
https://www.amazon.com/Lighted-Rocker-S ... B007PB7JDI

SysProg
Posts: 2
Joined: Thu Nov 09, 2017 4:25 pm

Re: Question from a newbie about switches

Post by SysProg » Sat Nov 11, 2017 7:29 am

Danv,

Thank you! Since I want to use a lighted rocker switch, do I connect a ground wire to the middle terminal(s) or will it light up when toggled to the on (Closed) position?

I am assuming that I connect the 12V power source to one side of the switch (bottom or top terminal) and the 12V output to the same side (other non-middle terminal), correct?

Harley

Omgitskillah
Posts: 9
Joined: Tue Nov 28, 2017 11:33 am

Re: Question from a newbie about switches

Post by Omgitskillah » Tue Dec 05, 2017 8:34 pm

Hi Harley,
To help out Danv, if using a DPST, connect the common line to your circuit and eitger of the poles to 12V or 24V.

If using a DPDT, the connection is still the same but the switch will have 3 stops when toggled instead of two. The middle (often) stop is for off and either side is 12V or 24V respectively.

Either way you will not need GND. The switch should be high side. Meaning it should cut power to the circuit.

All the best!

Killah

Post Reply