ground Zero, gzua 1.1000

[trean27]

I had a picture in Phone. But can measure the resistor off board later.

 

[Perry Babin]

How high does the rail voltage go as you increase the 12v DC input voltage?

 

[trean27]

11v =52v
12v =56v
13v=60.8v
14v= 65.5v

 

[Perry Babin]

I don't think you've reached the regulated voltage at 14v.

What's the DC voltage on terminals 1 and 2 of the TL494 at 14v in?

 

[trean27]

Pin1. 2.12v
Pin2. 2.95

 

[Perry Babin]

I think the regulation is more like a limiter in this amp. The regulation will begin when those two voltage reach the same value. I think that would be at about ±80v.

What is the DC working voltage for the rail caps?

 

[trean27]

I dont know if i Follow. The capacitor is 80v max. And at 14 volt i got 65.5 v rail to rail.

 

[Perry Babin]

I wouldn't expect to see any regulation with the voltages expected at the B+ terminals. The regulation may simply be to protect the capacitors. In the other diagram, the calculated regulator voltage is about 99.5v and the amp uses 100v caps.

 

[trean27]

This amp uses 80v.

 

[Perry Babin]

Is there still a question as to the function of the regulator circuit?

 

[trean27]

Thanks for the help.