13-02-2020, 09:30 AM
Thank you Frank.
These monitors are actually pretty tough. My only casualty so far is a diode as mentioned in post #18. I'm not convinced this failed due to my experiments. It's hard to see how it could have been run outside its ratings. To minimise risk to silicon and wound components I've kept the supply voltages down as far as possible during most of the work. The worst that's happened has been a bit of discharge from the EHT probe to the dag on the CRT. Just a matter of careful positioning.
There have been times when the line scan has been going crazy but it's not killed anything.
The only thing that's worrying me slightly is how hot the back panel is getting. It's the heatsink for all the power transistors incuding my additional darlington. I've just run up an unmodified 625 version to see how hot that gets. Might end up moving the darlington to the bottom panel.
These monitors are actually pretty tough. My only casualty so far is a diode as mentioned in post #18. I'm not convinced this failed due to my experiments. It's hard to see how it could have been run outside its ratings. To minimise risk to silicon and wound components I've kept the supply voltages down as far as possible during most of the work. The worst that's happened has been a bit of discharge from the EHT probe to the dag on the CRT. Just a matter of careful positioning.
There have been times when the line scan has been going crazy but it's not killed anything.
The only thing that's worrying me slightly is how hot the back panel is getting. It's the heatsink for all the power transistors incuding my additional darlington. I've just run up an unmodified 625 version to see how hot that gets. Might end up moving the darlington to the bottom panel.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
