TVs Monitor EHT Voltages etc

[CAWORK]

While I agree that TV repairs etc are complex and are not a DIY job, I would like to point out one or two things.

When doing a TV servicing course some years back, my lecturer claimed that the EHT could give a very nasty jolt and burn. However the current is very low in microamps and there have not been very many deaths at all from EHT shocks, and that during TV servicing the mains power supply voltage of 230v is more dangerous. I am pointing this out since some members on here have before said a little different.

The lecturer himself has had much experience in the TV trade before and also knows (regarding other kinds of things) what TVs have been known to be capable of.

Any comments etc?

 

[breezer]

your lecturer is right.

did you know?

many years ago when tvs were first "common" and had varnsih for insulation a tv repair man was killed by the HT

 

[ultrascan]

Back in the mid 30s and early 40s , the EHT was derived from a mains Transformer.
This was capableof deliviring a very high voltage at 50Hz or DC depending on which end you decide was a good idea to poke at the time.
at around 8000 volts.

very much Killing Power.
As Sets developed, High frequency EHT generators were used, and operated at around 10.250 Khz, now 15.625 Khz. This provided High voltage at a low current.
It is classed as RF. (radio Frequency)Yes it will tingle a bit. and yes it can brn a bit.
but is not likely to kill you. dispite that with monochrome receivers, the eht would be around 15000v, and for colour, about 25000v.
the trick was to hold a large sheet of metal tightly with both hands, and draw an arc from the final anode connector. however I do not recommend you try this at home.

A microwave oven operates at around 5000v falling to 2500v when the magnatron has started up.and a hefty charge can be stored in the capacitor even if the unit has been powered down for a long time.
The power generated is mains derived and will Kill. if not treated with respect. so if you do not know or understand how and why it works.
Leave it to the experts, and don't even think of taking the lid off.
A funeral costs a lot more than a repair bill!
Take care, ultrascan