Philips radio BCA628A (Algemeen)

door Pandu Rajan , 25.04.2022, 07:32 (943 dagen geleden)

Dear friends
I am in the process of restoring the above set. After completing the restoration and applying power following readings have been noted: The set is working properly with all the valves in position. The rectifier valve is AZ41.

1. Incoming voltage - 226V A.C.
2. Secondary transformer voltage - 275-0-275
3. filament voltage ( 4V) - 4.41V A.C.
4. Filament voltage ) 6.3V) - 4.68V
5. Voltage at C1 - 322V
6. Voltage at C2 - 299V

I am unable to understand why there is such high voltage at C1? The transformer is original and all the connections are also original. As per the schematic the voltage at C1 should be 260V and at C2 -235V for an incoming voltage of 220V. The set is similar to BCA645A. The schematic for BCA645A is in the site. In most of the set which I have restored for a 260V/255V d.c. voltage at C1 the secondary transformer voltage is 235 -0-235V or 230-0-230V. But in this set the secondary transformer voltage itself is very high. I have measured the current in the secondary winding going to AZ41 pin 2 is 22ma on load.

Kindly advise.

Regards
Rajan