HV probes, & flyback measuring.

There are lots of good HV probe styles available. I kinda like a probe with a built-in analog meter, just because it is simple to use, and doesn't require a separate meter, although I have and use the types that plug into a DMM too.

See the FAQ section about flyback/IHVT testing. One important test is an inductor ringer, which can check for shorted turns. There are several tests/checks to be done to analyze the quality of flybacks. Some Sencore testers have a variable horizontal drive signal that can be used to drive the primary of the transformer (out-of-circuit), for a relative output test.

Cheers WB ............

In our shop we prefer using a stand alone instrument for measuring the CRT high voltage.

We are now finding that investing in to anything to do with servicing CRT equipment is becoming more limited and less feasable as time goes on. The cost of the flat panel TV sets and monitors are dropping every month. At the same time, manufactures are not interested in having the burden of having parts distributions for the CRT models.

As for the LCD and plasma devices, these are mostly serviced at the modular level. For servicing, they usualy require dedicated tools and service information.

Wild Bill wrote:

I use a Fluke HV probe that plugs into my multimeter. I think it's rated

James Sweet wrote in news:AQyPh.2780$5x6.2567@trndny02:

More likely 50KV.

Just checked and it's 40KV, at any rate it goes higher than I've ever had to measure.

James Sweet wrote in news:nJIPh.1685$hI4.1050@trndny08:

let's hope you don't encounter any CRT anodes at 40KV.....unless you're wearing your lead undershorts! ;-)

From the look of the thing I suspect it could safely go much higher. Not to say one should routinely abuse something, but Fluke is well known for using conservative ratings with lots of safety margin.

James Sweet wrote in news:QBTPh.336$yL1.332@trndny04:

I was thinking of X-ray generation at voltages above ~25KV,not the safety of the probe.

I've come across TVs and monitors with 35KV anodes, mostly projection or very high resolution.

I saw on a website once they were trying to generate xrays with a CRT, even up as high as 60KV or so there was not a measurable amount due to the leaded glass. A few rectifier tubes though did generate enough xrays to take a few pictures.