Circuit Modification

[BillionPower]

Has anyone Used Transistors to replace STK0039 Tip35 & 36 Tip41 & 42 2 diodes and 47 ohm and 470 ohm resistors. Can someone look at this Mod and see if This can work and what other modifications needed.

Thanks

[Cybergent]

Here you find the datasheet of the STK0039 and the internal circuitry.

http://www.datadart.com/al/sanyo/Stk00.pdf


Hello! to Jamaica. I´ve been there 4 times.

[Tube_Dude]

Originally posted by BillionPower
Can someone look at this Mod and see if This can work and what other modifications needed.

Thanks

Hi Billlion Power!

Yes ...your modification will work!

You must take care of the thermal tracking of the output transistors and put a pot for adjusting the bias...i prefer to use a transistor as VBE for traking, but the diodes can work if you put them in thermal contact with the output transistors.


So ...turn on your soldering iron...



PS:Maybe the compensation need some fine tuning......

[millwood]

I would put a 0.47-1uf cap parallel to R4 to reduce switching distortion.

[Duo]

Wouldn't it be even more effective to put the cap across the whol diode network?(right from base to base?)

I'm not perfetly sure on this one, but I've done and seen it before with good results. Any opinions?

[Tube_Dude]

Originally posted by Duo
Wouldn't it be even more effective to put the cap across the whol diode network?(right from base to base?)

I'm not perfetly sure on this one, but I've done and seen it before with good results. Any opinions?

Yes!!! ..It's allways a good design pratice to put a capacitor across the biasing network!

[Duo]

thx for your confirmation , I figured that was logical..

[BillionPower]

Thanks guys for your Contribution.

[Duo]

your welcome

[BillionPower]

I did the modification and it worked like a charm. bias -/+ 0.56v.