having problems with DOZ, help request

Status
Not open for further replies.
Hi,

I've build one channel of the DOZ, and am stuck with some problems which somehow i can't seem to identify.

Ok.. setup is as follows:

I'm using one transformer per channel, output is 24V(34V after rectification), 3 Amp.(the transformer has only 2 leads on the secondary)

Facts: Voltage across 1ohm resistor is ~1.75V(drawing 1.75 A) nomatter what I change in VR1 and VR2.
I am using a 10R 17W resistor after the power supply capacitors and it gets bloody hot(and I mean... HOT).
Voltage across emitter and collector of output transistors is very low ~5V, again, nomatter what I change in the variable resistors.
The output is obviously very distorted.

Now, the odd thing, I tryed using a 24-0-24 transformer, connecting the 0 to circuit ground, and not connecting the DC - of the rectification bridge, and VR1/VR2 seems to work, which probably means all connections are correct(I checked the circuit 6 times).

Is there any problem in using one transformer per channel? I really am lost here, if anyone has a suggestion, It'd be most appreciated.

Thanks,

Tiago
 
Status
Not open for further replies.