How to modify the circuit

質問

Hi!

Once check the following link:

http://www.electronicshub.org/150-watt-power-amplifier-circuit/

By using the circuit present in this post, we can build 150w power amplifier circuit. I want to build 220w power amplifier circuit. Can anybody suggest me what are the required changes to be done to this circuit? I want to do build this circuit on next week.

Thanks,
Sudheer.

回答No.1

xpopo

Hi! Sudheer.

I have checked the sckematic on the "http://www.electronicshub.org/150-watt-power-amplifier-circuit/". And, I find it seems not working.

The schematic seems just an idea but not tested in the real world. It has several problems for the proper behavior as followds:

1) There is no biasing circuite for the base of Q3. There exist no DC path to the base of Q3.

2) The circuit for setting the idle current for having AB class drive does not work as expected.
The diodes of D1 and D2 cannot work for setting the optimum idling current for SEPP output stage.

3) Frequency characteristics of this amplifier is appeared not to be optimum for audio play-back.
The value of the capacitor C4 should be around 100uF to get the lowest band at about 20Hz.

So that, I made some modifications on that schematics and I up-loaded the modified schematics on "http://yahoo.jp/box/g5mxbH".
The power supply should be increased to +/-60V. And other modified points are indicated on that up-loaded schematics.

And please take a look on the Bill of Materials, "http://yahoo.jp/box/8a7Efk".

That's all. I hope you can get the good results.