On Friday, March 4, 2016 at 7:31:55 AM UTC-5, Phil Allison wrote:
wrote:

Here is the Schematic: http://komkris4000.webs.com/lk150%20schematic.gif

It is eating the 150uF @ 75V filter caps - I replaced the OEMs first with 75V, 105F caps, they lasted about 20 hours. Then 100V, they lasted about 30 hours. The manifestation is increased HUMMmm, and the caps start to swell.


** That schem looks wrong.

No way 75V electros should be fed from a 100V AC winding.

75uF @ 150V is more like it.

Is the secondary tapping really 100V rms ?

The hand written " -31 " is wrong too, should be more like -45V.


.... Phil

Phil:

I think you are right. In any case, the diode *was* in backwards - it is in a silly little brass shield grounded to the chassis - looks like a bit of brass tubing with a soldered on lead that covers the diode (1N4007 now, replacing a wrong-way 1N4004). I will check voltages with the existing slightly swollen caps for now, then replace them with appropriate voltage and capacity units - but no less than 180V at this point. As for testing purposes, I will be right there and with an eye on the current meter, I have no worries about a few minutes with bad caps.

Peter Wieck
Melrose Park, PA