[EDIT] My real question here is: can a magnetron from a microwave oven be used to output low power microwaves? If so, how can I achieve this? If not, what is a source for low power microwaves? In this context, low power means that I don't intend to output microwaves that are dangerous to a human being.
[/EDIT]
Is it feasible/reasonable to drive a microwave oven magnetron from a CCFL backlight driver? From what I've seen, the voltage produced by the CCFL driver should be in the ballpark what a magnetron accepts.
I want to use the radiation for measurements, so I don't need the high power a megnetron would typically produce and a lower power rating makes this feel much safer.
Best Answer
If you can somehow get 4KV out of a CCFL driver it should work. I don't think so!
A magnetron doesn't start conducting until about 3.9KV, then it conducts heavily like a 4000V Zener.
The safest way to do it would be to make a power supply by pulsing a car ignition coil, arranged so it puts out a negative voltage to the cathode. You will need something like a scope soldering iron transformer for the filament, which takes 3.3V & about 11A.
If you want a smooth output, you will need a capacitor rated at more than 4KV and a string of at least 5 1N4007 diodes as well.
The other option is a 7.5KV neon sign transformer and a bridge of 4 strings of at least 5 1N4007s. Neon sign transformers are rated at o/c voltage & s/c current, &, as far as I was able to find out, a 30mA transformer produces about 26mA at a tube voltage of 1/2 the transformer o/c voltage, so it will give you about 24.4 mA rms (about 22mA av) at 4KV. Magnetrons normally run at about 300mA, so it will produce about 1/14 of the normal output power. Keep it away from your eyes though. Check out this advice by Neil_UK on Magnetron, and Microwave - Electrical Engineering Stack to someone else contemplating using a magnetron outside of the oven. It will not only give you a good laugh with his sense of humour, it is very good advice.