Analog Multiplexer - NEED HELP! =D

[ghty56]

Hi guys,

I have a power supply that can only take positive voltages but I would like it to be able to take negative voltages. To achieve this normally, I have to manually take out the positive and negative pins and put them on the negative/positive input terminals on the power supply respectively.

I would like to have this done automatically using some sort of analog multiplexer where it takes the two positive/negative pins as inputs and has two outputs that go into the positive/negative terminals of the power supply. Ideally, a signal from the PC would provide the switch (high/low).

I'm more of a software guy so my electronics knowledge is a little basic.

I figure I would need some sort of analog multiplexer with tristate. I also am a little worried of the potential voltage loss that may occur in the multiplexer circuitry.

Since you guys are way more pro than me with this sort of thing, I was wondering if somebody could please give me advice on how to approach this?

Thanks in advance!

 

[Nigel Goodwin]

It's really unclear what you're wanting to do?, but if it's just swap the positive and negative wires over, a DPDT relay is all you need for electrical control, or a DPDT switch for mechanical control.

 

[Speakerguy]

I agree with Nigel.

You need a DPDT switch (or relay) with On-Off-On action. Look for something under Toggle Switches at Digikey.

 

[ghty56]

No you guys are right, a relay is what I need.

I'm thinking of using two single pole SSR controlled via the parallel port. I'll let you know how things go, thanks!