View Full Version : Stupid SPDT throw question...

03-14-2012, 04:05 AM
this should be totally obvious to most people who dont even have the fantest idea about electronics but when it comes to switches im totally dumb unless i have one in front of me with a power source and light. Im looking for a way to have an off and switch between a wall power supply and a custom built dc to dc regulator via a simple two pin connector, i drew this up as a simple example it seems right to me but im just not sure for some reason,


Mike Green
03-14-2012, 04:30 AM
Your diagram will work if you have the right sort of switch. There are 3 position toggle switches where there's a center-off position. That will do what you want. Other toggle switches have two positions where you'll connect your circuit to the connector in one position and to the wall power supply in the other position with no real off position. That's not what you want.

03-14-2012, 06:59 AM
Personally I would use a DPDT switch, either ON - ON or ON - OFF - ON, depending on the way power is to be applied.
For the simple reason that I do not trust wallwart adapters, especially when the current draw becomes critical. I would use this setup: