Microwave capacitor question.

[sm0ky2]

Yes, but this capacitor has a small capacity 0.90 Uf

Leo48

"microwaves" have a very tiny wavelength, the one used for this capacitor has the wavelength of 12cm
When you compare this to the diameter of the water molecule, (0.275nm)
you can see this hits on a multiple of the 6 & 1/6th resonant node.

The excitation frequency of the water molecule, that we use for cooking food, is (approx.) 2.45 Ghz (2,450 Mhz)

this means that the capacitor is charging and discharging at a rate of 2,450 million times per second.
when you flip the DC switch on this cap, it will reach maximum capacity before the rest of your circuit even finishes turning "on".... the large plate size allows for a high voltage to be stored, but there is very little "quantity" stored inside.

you can consider the "farad rating" to be like the size of a swimming pool.
Say the pool has 1,000 Gallons in it.
If "current" was the amount of water flowing out, you could drain the pool at 10 gallons per second for 100 secs.
Or you could drain the pool at 100 gallons per second for 10 secs.
etc.
So, using this capacitor, theres only a tiny bit of "current" you can pull from it, at whatever voltage you charge it to.

solution? add more caps in parallel.

[leo48]

 
No no the capacitor present in microwave ovens A blend is used to straighten the HT diode
and doubling the voltage of 2100V AC adapter to power the magnetron at 4200V dc
negative, and 3.5V 10A per filament ignition.

Leo48

[Paul-R]

Bear in mind that it probably has a 1megohm resistor connected across the terminals, situated just under the top casing.

It might be possible to drill it out by drilling a few mm into the unit between the terminals. (Connect a multimeter across the terminals until the value drops to nil). Also, the unit may be full of oil and so, it may be a messy process.

If you have a few of them, maybe from your local recycling centre, you could chop up one to see what's going on. They look well made.

[massive]

shake the cap , you will hear the oil inside . all the info is written on the cap . it charges and discharges at the supply frequency , either 50hz or 60hz .
MW oven uses a Villard circuit

[sm0ky2]

No no the capacitor present in microwave ovens A blend is used to straighten the HT diode
and doubling the voltage of 2100V AC adapter to power the magnetron at 4200V dc
negative, and 3.5V 10A per filament ignition.

Leo48

so the 2.45 Ghz is actually a magnetic response??
I never looked at the circuit boards in these things, I usually just throw them away when I strip the magnets out....

I always assumed they were doing it with IC chips or transistors and then sending 2.45 Ghz through the magnetron....