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Re: [Amps] High Voltage Switching Supply (Bob D.)

To: Victor Rosenthal 4X6GP <>,
Subject: Re: [Amps] High Voltage Switching Supply (Bob D.)
From: A J <>
Date: Wed, 6 Mar 2024 13:21:42 -0500
List-post: <>
I was given two Lambda 202A-3KV-POS-PFC I have no idea what they came out of.

Have not had the opportunity to test them. I posted the specs of what the manufacturer rated them. Which seems would be fine for many applications.

No idea of they will even work in an amp or what the output looks like or how loud the fans are.

I have seen these on ebay for ~150.00

Something like this might be what you are looking for.




Input Voltage Range[AC]         

180 to 254VAC

Input Frequency Range   

47 to 63Hz

Rated Output Voltage[DC]        


Output Voltage Range[DC]        

0 to 3000V

Average Capacitor Charging Power        


Peak Capacitor Charging Power   


Charge Current  


Continuous DC Current   


Continuous DC Power     




Power Factor    



85% Typ.

On 3/5/24 12:20, Victor Rosenthal 4X6GP wrote:
I don't know if it's been mentioned yet, but a 'feature' of any supply for a microwave oven is that it is designed for a short duty cycle.  A "1500-watt" supply will not provide 1500 watts for amplifying compressed SSB, CW, or digital transmissions over a period of time of more than a few minutes. You would have to derate it and probably provide cooling.

73, Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5

On 05/03/2024 17:09, Bob D. wrote:
Hi Steve,

"Well, there's no free lunch... Although these inverters present an
interesting idea, this particular one uses a flyback transformer to
generate the HV, which is unregulated and so varies between 2200 and as
much as 6 kV, the youtube author said at one point in his first video."

The supplies are tightly regulated.They are regulated for power via current sensing on the AC mains side of things. Something like 2% per one article.
It's what makes that type oven so nice in the kitchen. The one in my
kitchen can thaw from the freezer without cooking!
It will melt butter without popping. Best thing is the "sensor reheat"
mode, It steams vegetables perfectly.

I am not an EE and welcome any assistance in understanding this thing.

I think the small IGBT heatsink is possible because the flyback topology
allows for switching at zero current(voltage).

So far I've gathered that:
The cook power setting signal is PWM 220Hz(per the referenced videos) with
no indication as to delay or hysterisis, if any, in response;
220Hz will limit the minimum response time of any voltage regulation
feedback scheme.

My thoughts are: That a minimum load and enough capacitance will allow me
to repurpose the cook power setting and hopefully hold voltage to within
There is minimal filtering on DC feeding the inverter so 20 uFd should be
adequate for filtering the 120Hz feed through; If the power control
feedback response
is no more than a cycle or so at 220 Hz, the 20uf will be adequate; My
first task in learning if this will work is to measure the response time of
the power feedback loop;
If the existing control loop is too slow, an impractical amount of
capacitance may be required for ham amplifier regulation.

73, -bob ah7i

Not knowing specs for the black box regulator, I'm doubtful there us any
approach to learning if this will work aside from cut and try.
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