Hi,
Just want to ask for an explanation why my amplifier overheats when using transformer with 22VAC / 3A and when I use 26VAC / 5A the amplifier is cool.
My amp can go up to 300W. 😕
Just want to ask for an explanation why my amplifier overheats when using transformer with 22VAC / 3A and when I use 26VAC / 5A the amplifier is cool.
My amp can go up to 300W. 😕
Insufficient info. What voltage range is it designed for? What are the controller / driver / output chips? What is the overheating part?
My first guess would be switching losses from insufficient gate drive.
My first guess would be switching losses from insufficient gate drive.
Im using TDA8950. Voltage rail range is 12V - 40V. The overheating parts are the bulk caps for the power supply, the IC, and the output filter which is never
encountered when I use higher rating transformer as mentioned before.
I would check for bus pumping at lower supply voltages.
Capacitors shouldn't get warm unless the ripple current is too high or supply volts are too high. Bus pumping can pump up the supply rails.
I found I can get quite a few class d amps to bus pump on low frequencies.
Capacitors shouldn't get warm unless the ripple current is too high or supply volts are too high. Bus pumping can pump up the supply rails.
I found I can get quite a few class d amps to bus pump on low frequencies.
My supply is in full-bridge config and as i researched "bus pumping" can occur on half-bridge amps.
Is this an amp you built, or is this a "board amp" that you purchased? I ask because my experience with some of the Class D amps has shown me that:
A.) There are many fakes, and
B.) Even if that's not the problem, some of the more reputable companies even have moved production to facilities where board production leads to sloppy dip soldering.
For example, I recently had a batch of TDA7492. One board would work. The next not. The next work, but not with 4ohm load only 8ohm, next fine again, etc...
So, there's that....
A.) There are many fakes, and
B.) Even if that's not the problem, some of the more reputable companies even have moved production to facilities where board production leads to sloppy dip soldering.
For example, I recently had a batch of TDA7492. One board would work. The next not. The next work, but not with 4ohm load only 8ohm, next fine again, etc...
So, there's that....
I built it my own. I found the solution - layout problem between IC pins and voltage rails. Thank you for the insights. 🙂
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