1 Sep
1999
1 Sep
'99
11:13 a.m.
Tony,
At 07:08 PM 9/1/99 +0100, you wrote:
It should be now. Let me know how many chars/line you're getting.
But they both hurt! Color TVs use ~25kV and if I remember right most
B/W sets use ~18 to 20 kV depending on the CRT size.
Yeap, unless they've changed in the last couple of years.
At 09:56 PM 8/31/99 -0700, Don wrote:
[Could you please limit your line length to something sane, like 80
characters max]
And I being more cowardly like to power down and let sit for a while and
make the adjustment 'cold'. Then power up and see how you did. Repeat if
necessary.
That's the smart way to do it! That CRT
high voltage sure hurts! But
Colour is a lot worse than monochrome...
But to rotate the yoke, you're not working very near the EHT. The only
thing you have to worry about is the 1kV-ish pulses on the horizontal
deflection coils.
Unless the HV arcs. I've seen it happen more than once. Even 1000
volts isn't pleasant!
beware that the CRT can act like a capacitor and
store charges for a LONG
time. I used to take new CRTS out of the shipping boxs where they had been
sitting for a year or more and they would still bite me! Also most
monitors and TVs have a hot chassis and one side of the AC line is
connected directly to the frame. So unplug them before touching it and
Not really.
TVs : Certainly in Europe, almost all modern TVs have an isolated
chassis. Mainly because all our TVs have a 'SCART socket' which carries
line-level audio, composite video, RGB, etc. It's a lot easier to isolate
the PSU (most TVs have an SMPSU anyway) than to isolate the dozen or so
signals on that socket. I can't comment on US-TVs, though -- are they
really still hot-chassis?
Monitors : For much the same reason (it's hard to isolate a composite
video signal, at least without mangling it), almost all monitors have
an isolated chassis. Having worked on dozens of monitors from just about
every manufacturer, I've come across exactly _1_ that had a hot chassis -
the 110V version of the TRS-80 model 1 monitor. Every other monitor has
been isolated.
I've only worked on a few monitors so I'm not an expert but why take a
chance? The TRS model I monitor was a modified TV. It and others like it
would almost certainly have a hot chassis.
I don't think finding a hot-chassis is much of a worry here.
Then you're lucky!
Joe