How to Bias voltage Testing of Power transistor

[hifiramr]

Hi I just want to know basic tutorial how to do BIAS testing of power transistor on my diy power amplifier assembled board how to measure it do we need two multimeter for it please guide me.Very new to DIY

 

[Fantastic]

You probably mean you want to know " how to set the bias current in the power output transistors" !
Do a Google search and you will come up with numerous notes on this. They will be much longer and descriptive than writing messages on a forum post !
You haven't even given a circuit diagram to get instructions.

You need something to turn the bias preset and one multimeter.

Since you say you know nothing, you NEED to READ what's on the Net and how to protect your amp from blowing up by doing something wrong. They recommend resistors on your supply lines and light bulbs on the mains line of the transformer ! Please Google and get a ton of information.

 

[sachu888]

My sincere advice,please don't do it if you know nothing.Mains voltage are lethal
Please google and ask manufacturer or kit vendor for detailed instructions.

Regards,
Sachin

 

[omishra]

Agree with Sachin. Please get in touch with kit manufacturer. Bias setting depend on circuit and part values. Also before powering up, you need to set basic stuff which is usually small or no bias. Then set bias according to manufacturers recommendations.
Otherwise on first power on itself, you may risk overheating and destruction of power transistor.

 

[diesel engine]

I dont want to discourage you. In electronics, especially in audio, people always learn by breaking something. If you are ready for that, go ahead. But I would like to advice to start from something inexpensive. First of all, find all tech details about the amp you can. find the safe maximum bias currunt. connect a multimeter across one of the emitter resistors. try adjusting the bias using the pot. actual bisa current is measured viltage divided by the resistance. And read some basic text, learn the basics. Play it safe. Respect the mains electric line. Happy DIYing.