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microwave oven inverter P.S. revisited
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microwave oven inverter P.S. revisited
On Sep 12, 9:49*pm, Grumpy The Mule wrote:
wrote : Yeah, I was planning on using pretty much the whole input section to the PC power supply. The one I am looking at I think I can cut out the whole circuit with a coping saw and mount it on some standoffs. This would put the rectifiers and caps on a seperate little chassis and I wont have to shoehorn in the 'lytics on to the inverter board. I was noticing that the schematic for the 120VAC uwave inverters is pretty much the same as the 240VAC inverter. I was expecting mains input to be different. What I was expecting was a voltage doubler on the 120VAC board since the 240VAC board used a bridge. This would mean that the inverter section is designed to run off of anything from 150VDC to 300VDC . I need to take a closer look at just what are the differences in the 120 and 240 inverters. Jimmie Jimmie Frankenstein style construction. *Hopefully you'll be tempted to shout "IT'S ALIVE!" but without the arcs and sparks. A 2:1 input range is a piece of cake for a flyback. *An 8:1 range isn't unheard of in commodity products. *Not being strictly bounded by the transformer (coupled inductor) turns ratio can be handy! There need not be any differences in the power components. The control parameters important to operation of the oven might need adjustment though. That said, optimization for each range could save a few coins. Make a million ovens or two and it adds up.- Hide quoted text - - Show quoted text - I went through the parts list for each power supply and their are some different part #s for the 120vac compared to the 240vac unit and the wiring is a little different. Grumpy, did you want a detailed schematic or did I already give you one? Send me an email and I will get one to you. There are part#s for everything. Maybe you could order just the transformer if you wanted. Jimmie |
microwave oven inverter P.S. revisited
Thanks for the schematic Jimmie.
The description of the inverter circuit translated by google says it's both variable frequency pulse and width modulated er... I think. This Could be critical conduction control. I couldn't find any mention of the flyback topology but my Portuguese consists of only a dozen or so words that I learned while living on the east coast and five of those are unseemly. ------------------------------------------------------------- This Power Supply Reversing receives the 120v or 220v 60Hz AC and provides the entry for the 4000 Vdc the magnetron tube, before performing the same function made by the processor and high-capacitor and diode, high. .. The entry of tension AC120V or 220V 60Hz is retificada immediately to a voltage DC. .. Voltage DC This will feed a device IGBT switching required. This device will chavear On and off for 20 to 40 kHz PWM (Pulse Wide Modulation) the sign of the microprocessor in the DPC. .. This microprocessor commands the processor high voltage to amplify and until 2000Vac 3Vac about by the processor. .. Then a circuit of half wave rectifier folder, which consists of a diode and high voltage capacitors, generate 4000V required for the magnetron. .. The output of the magnetron is always monitored by the current output of the processor internally reverse the circuit. |
microwave oven inverter P.S. revisited
On Sep 14, 5:56*pm, Grumpy The Mule wrote:
Thanks for the schematic Jimmie. The description of the inverter circuit translated by google says it's both variable frequency pulse and width modulated er... I think. *This Could be critical conduction control. I couldn't find any mention of the flyback topology but my Portuguese consists of only a dozen or so words that I learned while living on the east coast and five of those are unseemly. ------------------------------------------------------------- This Power Supply Reversing receives the 120v or 220v 60Hz AC and provides the entry for the 4000 Vdc the magnetron tube, before performing the same function made by the processor and high-capacitor and diode, high. . The entry of tension AC120V or 220V 60Hz is retificada immediately to a voltage DC. . Voltage DC This will feed a device IGBT switching required. This device will chavear On and off for 20 to 40 kHz PWM (Pulse Wide Modulation) the sign of the microprocessor in the DPC. . This microprocessor commands the processor high voltage to amplify and until 2000Vac 3Vac about by the processor. . Then a circuit of half wave rectifier folder, which consists of a diode and high voltage capacitors, generate 4000V required for the magnetron. . The output of the magnetron is always monitored by the current output of the processor internally reverse the circuit. This thing seems to be regulated primarily by the input CURRENT which would be the same as power and David Smith said in his discription. I think the answer to using it as a power supply is to turn it into a VOLTAGE regulated power supply by taking a voltage sample off of the HV transformer, possible by adding a couple of turns coil to the transformer, and replacing the input from the current transformer with this one. Naturally the inpit to IINDO may have to be suitably modified also. I cant remember now where I saw it refered to as a.flyback circuit but it said "FLYBACK" no trouble with translation. I will look for it tonight. Jimmie |
microwave oven inverter P.S. revisited
On Sep 15, 12:57*am, wrote:
On Sep 14, 5:56*pm, Grumpy The Mule wrote: Thanks for the schematic Jimmie. The description of the inverter circuit translated by google says it's both variable frequency pulse and width modulated er... I think. *This Could be critical conduction control. I couldn't find any mention of the flyback topology but my Portuguese consists of only a dozen or so words that I learned while living on the east coast and five of those are unseemly. ------------------------------------------------------------- This Power Supply Reversing receives the 120v or 220v 60Hz AC and provides the entry for the 4000 Vdc the magnetron tube, before performing the same function made by the processor and high-capacitor and diode, high. . The entry of tension AC120V or 220V 60Hz is retificada immediately to a voltage DC. . Voltage DC This will feed a device IGBT switching required. This device will chavear On and off for 20 to 40 kHz PWM (Pulse Wide Modulation) the sign of the microprocessor in the DPC. . This microprocessor commands the processor high voltage to amplify and until 2000Vac 3Vac about by the processor. . Then a circuit of half wave rectifier folder, which consists of a diode and high voltage capacitors, generate 4000V required for the magnetron. . The output of the magnetron is always monitored by the current output of the processor internally reverse the circuit. This thing seems to be regulated primarily by the input CURRENT which would be the same as power and David Smith said in his discription. I think the answer to using it as a power supply is to turn it into a VOLTAGE regulated power supply by taking a voltage sample off of the HV transformer, possible by adding a couple of turns coil to the transformer, and replacing the input from the current transformer with this one. Naturally the inpit to IINDO may have to be suitably modified also. I cant remember now where I saw it refered to as a.flyback circuit but it said "FLYBACK" no trouble with translation. I will look for it tonight. Jimmie- Hide quoted text - - Show quoted text - While brows varios inverter circuits I began to wonder how difficult would it be to convert a pulse width modulated power supply into a power supply /AM modulator. Could this be as simple as appling audio on the feedback path between the output and the PWM circuit. Just an idle thought. Jimmie |
microwave oven inverter P.S. revisited
|
microwave oven inverter P.S. revisited
On Sep 15, 12:57*pm, Highland Ham wrote:
wrote: snip This thing seems to be regulated primarily by the input CURRENT which would be the same as power and David Smith said in his discription. I think the answer to using it as a power supply is to turn it into a VOLTAGE regulated power supply by taking a voltage sample off of the HV transformer, possible by adding a couple of turns coil to the transformer, and replacing the input from the current transformer with this one. Naturally the inpit to IINDO may have to be suitably modified also. ========================================== You might consider taking a voltage sample by 'tapping' a low DC voltage fraction from the HV output ,putting that into an opamp with adjustable output. You can see how this is done in an article *in QEX-July.August 1999 ,pages 50-55. 'A regulated 2400 V power supply ' by VE6AXW Frank *GM0CSZ / KN6WH Thanks Frank, but I dont have QEX or access Jimmie |
microwave oven inverter P.S. revisited
steve H wrote:
wrote: On Sep 15, 12:57 pm, Highland Ham wrote: wrote: snip This thing seems to be regulated primarily by the input CURRENT which would be the same as power and David Smith said in his discription. I think the answer to using it as a power supply is to turn it into a VOLTAGE regulated power supply by taking a voltage sample off of the HV transformer, possible by adding a couple of turns coil to the transformer, and replacing the input from the current transformer with this one. Naturally the inpit to IINDO may have to be suitably modified also. ========================================== You might consider taking a voltage sample by 'tapping' a low DC voltage fraction from the HV output ,putting that into an opamp with adjustable output. You can see how this is done in an article in QEX-July.August 1999 ,pages 50-55. 'A regulated 2400 V power supply ' by VE6AXW Frank GM0CSZ / KN6WH ============================================== Thanks Frank, but I dont have QEX or access Jimmie ====================================== http://www.realhamradio.com/hvreg.pdf for a schematic. hth Steve H ================================= Indeed ,that's the one. Tnx Steve for the interesting URL Frank GM0CSZ / KN6WH |
microwave oven inverter P.S. revisited
On Sep 15, 3:03*pm, Highland Ham wrote:
steve H wrote: wrote: On Sep 15, 12:57 pm, Highland Ham wrote: wrote: snip This thing seems to be regulated primarily by the input CURRENT which would be the same as power and David Smith said in his discription. I think the answer to using it as a power supply is to turn it into a VOLTAGE regulated power supply by taking a voltage sample off of the HV transformer, possible by adding a couple of turns coil to the transformer, and replacing the input from the current transformer with this one. Naturally the inpit to IINDO may have to be suitably modified also. ========================================== You might consider taking a voltage sample by 'tapping' a low DC voltage fraction from the HV output ,putting that into an opamp with adjustable output. You can see how this is done in an article *in QEX-July.August 1999 ,pages 50-55. 'A regulated 2400 V power supply ' by VE6AXW Frank *GM0CSZ / KN6WH ============================================== Thanks Frank, but I dont have QEX or access Jimmie ======================================http://www.realhamradio.com/hvreg.pdf for a schematic. hth Steve H ================================= Indeed ,that's the one. *Tnx Steve for the interesting URL Frank * GM0CSZ / KN6WH- Hide quoted text - - Show quoted text - Is there any more info on the circuit besides the schematic? This looks like something I could build and I probably already have most of the parts. I see it uses SCRs for switching. I guess there is no problem with latchup. I built a 400Hz inverter one time and it seemed to work for a while until one day it latched up on me and smoked. I had been using it to power some selsyn motors. Someone plugged a soldering iron into the inverter and I think it was a little too much load. I guess that is what I get for not labeling my outlets. Jimmie |
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