Quote:
Originally Posted by Argus25
Also, I guess for the CRT types where there is a resistive connection between the internal dag and the gun electrode structures, the stored bulb charge should self dissipate as there is a complete discharge pathway with the power off.
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That'll depend on the time constant formed by the CRT capacitance and internal resistors - I've no data on that, but they will be using large value resistances to minimise dissipation. So if you unplug the tube base socket very soon after switching off, then the CRT might not have discharged - leaving "CV" (see Sony extract) at a high potential, potentially
As I say, I much prefer to not take chances - it's practically zero effort to discharge (then strap a lead there to stop it charging up again), so why waste time analysing it when there's probably more pressing matters to think about?
Quote:
Originally Posted by Argus25
PS: What is a typical value current sense resistor for the application, also are they a physically large part ?
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They vary hugely depending on the design of the set - I'd hate to generalise. Beam currents are usually limited to a couple of milliamps or thereabouts, so you pick the resistor according to the voltage swing you need elsewhere. You might choose to tie the resistor to a rail rather than ground - it'll still do the same job. Or you might incorporate potential dividers and perhaps zener diodes. My knowledge on these things mostly come from Television Magazine - as a kid I used to love reading all the in-depth reports on new sets, even though I didn't understand most of it at first! I definitely recommend dipping into some back-issues if you're interested in the sorts of sets we saw other here (which might well have been very similar to what was sold over there - I don't know?):
https://www.americanradiohistory.com...n_Magazine.htm
As to the size of them, see earlier comment: they're only handling a few milliamps...