01-08-2020, 08:15 AM
(This post was last modified: 01-08-2020, 08:20 AM by Mike Watterson.)
Here is a scan from my own R&TVS.
So I snipped out C25, 100uF. This set uses too few or badly placed earth tags, so the wires snake around each other making unsoldering even more difficult than usual.
It started at 1mA, on a 6V supply, and rose to over 2.5mA before I lost interest. My electrolytic caps are now all old so I have the replacement 100uF 16V on 10V for a while. Current quickly dropped to under 0.1mA. I'll check does it actually have capacitance. So the original would have been over-running the 3V4 output valve filaments as well as under-running the other three.
The mains supply and power switching is a no-win on this other than using a shaver transformer (2kV or 4kV isolation and 20W power limit, most have a special core design and/or a thermistor on the primary side. ). If the neutral is to chassis and live to the rectifier, then EVERYTHING including the chassis can be live when the power is off, as it's the mains connection to chassis that's switched.
So I snipped out C25, 100uF. This set uses too few or badly placed earth tags, so the wires snake around each other making unsoldering even more difficult than usual.
It started at 1mA, on a 6V supply, and rose to over 2.5mA before I lost interest. My electrolytic caps are now all old so I have the replacement 100uF 16V on 10V for a while. Current quickly dropped to under 0.1mA. I'll check does it actually have capacitance. So the original would have been over-running the 3V4 output valve filaments as well as under-running the other three.
The mains supply and power switching is a no-win on this other than using a shaver transformer (2kV or 4kV isolation and 20W power limit, most have a special core design and/or a thermistor on the primary side. ). If the neutral is to chassis and live to the rectifier, then EVERYTHING including the chassis can be live when the power is off, as it's the mains connection to chassis that's switched.
