Janus regulator troubleshooting

[CoolJazz]

Hi,

I'm building my first PS, the Janus regulator from Jim Broskie.
I only attached the 6.3v heater fillaments to the pcb.
On first power-up, after a minute or so, one cap, C11, started to bulge and vent. C12 seems ok.

I'm sure the cap's orientation is correct and I don't know how to proceed from here.

Any help/suggestions?

tnx

 

[nigelwright7557]

Hi,

On first power-up, after a minute or so, one cap, C11, started to bulge and vent. C12 seems ok.

Any help/suggestions?

tnx

Either wrong orinetation or wrong voltage across the cap.
What is the input voltage and what voltage are the caps ?

 

[leadbelly]

My 1st guess would be that you grounded the heater circuit in more than 1 place, which is a common mistake for newcomers. Could you perhaps outline the different connections you made from the board to your circuit? Measured voltages and component values would help as well.

 

[CoolJazz]

The 6.3vac (measure 6.5) filaments are connected to pads A and B.
C11 is a 10000uf 16v cap, C12 is the same.

The pcb is not grounded anywhere, it's sitting on my table, not connected to anything but the transformer's 6.3vac filaments

 

[CoolJazz]

Ok, I just put a new cap in and measured the voltages.
Voltage across C12 is 7vdc but the voltage across C11 is -7vdc.
C11 blew again after some time.
Does that mean the cap's orientation is wrong or can it be something else?

tnx for the help