HV from Newer Microwave Oven Inverter 

Great demonstration-thanks

Nice vid! Minor correction: soft switching IGBTs converters operate in zero current switching (ZCS), because their turn off loss is much greater than their turn on loss; MOSFETs prefer operating in ZVS mode, opposite of IGBTs.

Great! Thanks

These look neat! I kinda doubt it is a standard flyback converter. It uses a single ended switch so I suspect class E amplifier like those HFSSTC's. The circuit may not be as simple as that since the output needs to be regulated but that may be what it is

Excellent video. I have a Panasonic NN-SN686S microwave with the same inverter. I picked it up cheap new since it was broken with the dreaded H97 code. I confirmed the problem was with the inverter (and not the magnetron) by swapping it with a working inverter. I then tried to troubleshoot the inverter itself: 1. Applying (with care), live 120V to the board (connector CN702), I was able to verify that the bridge rectifier (DB701) is working along with the zener diodes, filtering caps, and resistor trees to give good low voltage, low ripple rectified current (checked on a voltmeter and scope) 2. I removed the IGBT (Q701/H30R1103) and verified that it is working by testing resistance across the various G/C/E combinations along with doing a diode check testing both polarities across C-E, both with and without the gate charged -- it works 3. I tested the 2 opto-couplers (EC702, EC703) in circuit by applying a voltage across their inputs and checking the output... 4. I tested the choke and both the primary/secondary of the HV coils and they are low resistance - so intact 5. I tested the 2 HV rectifiers attached to the coils and showed they work (though they required about 6-7 volts to forward bias them) 6. I removed and tested the 2 HV capacitors (C701 and C702) and they tested to spec on my capacitance meter (0.28uF and 4.5uF), respectively 7. I tested in circuit, D703 and D704, they worked 8. I inspected the circuit board for cracks, burns, etc. -- there were none 9. I examined the remaining low voltage caps for any signs of burning or bursting - they all looked fine 10. I reflowed the controller IC, just in case... I put it all back together... no smoke... ran for about 6-7 seconds (fan light) but no heating and then H97 again... Given that not much else to go wrong, I'm thinking maybe the "mystery" controller chip was DOA... but no easy way for me to prove it Any other suggestions on what to troubleshoot? Jeff

Taught me a lot, TA!

Excellent video thanks....

I heard some noise coming from inverter board while working my Panasonic micro wave... And also micro wave doesn't working properly sometimes showing H97error code..what you think sir?..

6v filament 3amp secondary for magnatron connects to HV winding, 2 diode, 2 cap voltage tripleler.

for hv hentusiast, transformer are still used in microwave,inverters are only used in inverter microwaves but there are still some lower quality microwaves that still use mots

I've used a non contact voltage meter near the output that suggests a big voltage exists on an inverter microwave. But a second used maggy still not getting heating. Either I've got a faulty 2nd mag. Or the output is high but not at the right voltage. Edit: yep 2nd bad Maggy from supplier. They are sending another. Luckily I could confirm in identical working microwave

Very good explanation thankyou very much I want to know in have national 42 liter inverter oven but after changing 3 new magnetrons but dint work timer panel is inverter also I changed but nothing happen if 3 signal wires disconet unit turns off after few seconds then what will be the fault can u explain pls from India mumbai city waiting for your reply sir

sir my Smart inverter microwave LG wen power switch plug in show on display penal COOL or Fan on butt not heat pl exp me

Valor de la R701 por favor y si la puedo sustituir por otra mas comun

Found this video after attempting this very thing. Im using a signal generator with the exact output but having no luck..

Excellent video. My Panasonic inverter Microwave blows fuse while sitting idle. Sometimes after one hour and sometimes after one or few days while door stays closed. I checked all parts are ok and the microwave works good while fuse is not blown. Please give your comments. Thanks,

The leads do arc I disconnected The magnetron in one stand well back 😯

Why would they use a voltage doubler? Just use a higher voltage transformer. Seems silly to add components and complexity when the solution is very simple.

How high can the pwm duty cycle be? Not really familiar with pwm

Can this be converted into a battery nickel pole piece spot welder?

Can this work for the fractal woodburner machine?

hi, how’s can Chack the, HV-30-100MM

First the replacement of old NSTs, Now this replacement of MOTs, what's next???!! Electronic Pole Distribution Transformers???? , I better stock up on MOTs soon,

Explain with wering diagram please

So what can I use this for. I have a 13 year old son I'm looking to do some projects with. I tore up a microwave to find this inverter instead of transformer. Anything simple. We were going to make a power supply with the transformer, I wanted to show and explain it to him.

DAMNIT!!!!!!!! why would they replace the stud transformer!?

Looks like the motors they used on bottom plate spinner that are good power supplies when they are spun with 4 v it gets to 100 v on the plate spinner anyway. Without the gears in it. Just magnet. /induction coil. Not 2000 watts but plate spinner getting 100v from 4 volts spinning motor! Free electricity5.48 in looks like copper £ is too much. So little copper 2000 plus watts

Never buy this Panasonic inverter units, the do suck...mine died after only 4 months and almost no use, the inverter part is as costly as a new microwave

I bought 20 of these dam things today, for the solitary purpose of scavenging the diodes and about cried when saw they took the mots out. Bastards... the old folks were right and we should have listened back in the 80s. I don't care about heat, I care about scary, crazy, and possibly irresponsible hacking to achieve deadly power. So what I have to add a gd function generator to my tesla coil now?