cant figure out what kind of power supply i need

Thread Starter

Angryanimal

Joined Sep 21, 2019
3
hi, i dont know if im posting this in the right place, but i want to buy a diy amplifier board but i cant for the life of me figure out what kind of power supply i need. it has 2 ac inputs and the product page says (i've attached a picture) that you can use a dc power supply or a dual ac power supply, but it specifies that you need to use a three prong one, but i really don't know which power supplies they're talking about. i assumed you can just ad a ground or attach minus to ground and plus to one of the ac inputs? please help. oh and by the way the chip is TDA72941626466111352.png
 

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BobTPH

Joined Jun 5, 2013
4,032
You need either a center tapped transformer or a bipolar DC power supply.

A center tapped transformer will be marked something like 24V CT or 12-0-12V. They are the same thing. The point is it has to have a center tap and two equal voltage of opposite polarity with respect to the center tap.

Here is an example:

24V center tapped transformer

A dual DC supply will have two outputs of the same voltage, like this one:

dual 12V supply

These are just to illustrate, I am not recommending either of these.

Bob
 

Thread Starter

Angryanimal

Joined Sep 21, 2019
3
You need either a center tapped transformer or a bipolar DC power supply.

A center tapped transformer will be marked something like 24V CT or 12-0-12V. They are the same thing. The point is it has to have a center tap and two equal voltage of opposite polarity with respect to the center tap.

Here is an example:

24V center tapped transformer

A dual DC supply will have two outputs of the same voltage, like this one:

dual 12V supply

These are just to illustrate, I am not recommending either of these.

Bob
Thanks a bunch for the reply. will this bipolar power supply work? its 24V and 1.6A, also would you recommend me to build one on my own like ronsimpson showed in his circuit?
 

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Dodgydave

Joined Jun 22, 2012
10,085
Thanks a bunch for the reply. will this bipolar power supply work? its 24V and 1.6A, also would you recommend me to build one on my own like ronsimpson showed in his circuit?
Yes that will do , but you need to link the two Grounds together, it's a bit over the top for an audio amp, a simple center tapped transformer as posted in #3 will do .

Here are a selection of transformers that will do , the bigger the Va rating is better.

https://cpc.farnell.com/search/prl/results?st=25v transformer&sort=P_PRICE
 
Last edited:

LowQCab

Joined Nov 6, 2012
1,308
That ~1.5-Amp Switching-Supply will not supply enough Current for a ~70-Watt-RMS Amplifier.

Here is a Power Supply for a
2-Channel, ~70-Watts RMS, 100-Watts Peak, per Channel, Power Supply ...........
If You plan on using all this Power,
install 10-Capacitors, and get 2 quiet Cooling Fans for the Chips.
.
.
.
Amplifier Power Supply 1 Flat .png
 
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