Power Supply Pin-out help needed. Pics included!

[Treydogg77]

I bought a Altec-Lansing ACS340 Computer Speaker Set. I need the pin out for the odd ball power input. I know it requires 12v 8ma and was going hard wire the board but, I don't know which side is positive and negative. I've got a DVM whats the best way to find the + and - with it? Pics of the board are below.


Thanks for any help!

 

[(*steve*)]

My guess is that it's an AC , centre tapped input, probably far more likely to be 800mA or 1.8A than 8mA.

There's almost always something written near the power connector


OK, it's 13VAC 4A -- and it's centre tapped. look here.

 

[Treydogg77]

Thanks Steve! Please bear with me im a newbie... I've checked all kinds of websites but all of them are sold out. I have a handful of power supplies I check them for the correct voltage. Whats centre tapped and how can I tell which pin is positive and negative?


Thanks for helping me out!

 

[(*steve*)]

There is no positive or negative.

the wires leading to the rectifying diodes are the two "ends" of the AC supply from a transformer (and can go either way around). The centre tap goes to the connection on the board that looks different, i.e connects to a large area of copper.

 

[Treydogg77]

So I just need to solder the 2 wires from the power supply to each main input pins on the board and shes good to go?

 

[(*steve*)]

NO, there are *three* wires.

This device requires a centre tapped 13VAC power source.

 

[Treydogg77]

Steve, sorry man im confused. Are you trying to say the centre tap is like a remote wire? The board needs 2 Positives and 1 negative to operate?

 

[Resqueline]

A 13V center tapped transformer has three wires, all with power, two "hot" (6.5V) and one "neutral" (0V). It would be rectified to + & - 8V, for a total of 16V.

Now, looking at your unclear pictures, & Googling the power supply, it seems to me they're not center tapped, only plain two-wire 13V 4A (52VA) units.