Higher frequency

Thread Starter

Hellerx44

Joined Apr 6, 2021
11
Hi
How can i get high voltage high frequency power supply. I have zvs drive with flyback transformer. The maximum what I'm getting is 50kv and 21kHz , im fine with voltage ,but the frequency not too much i need in mega hertz. Any help. Thanks
 

ronsimpson

Joined Oct 7, 2019
2,535
The maximum what I'm getting is 50kv and 21kHz
Post your schematic and all the data you have on the transformer and magnetics. How much current!
What HV diodes, what transistor? What is the peak voltage and current on the transistors?
For decades I designed CRT monitors and TV sets. We made some very large monitors; some were very unusual. HV often was in the 35 to 40kv. The switching frequency for the monitors got to 120khz using junction transistors. Now I am working with much much faster transistors and diodes now. I have some 1700V IGBTs running but they are slow maybe 100khz is pushing them. I also have some HV SiC transistors that are much faster. Mostly I am working with GaN transistors rated for 650V & 1200V. They require some special thinking.

21khz is just above TV frequencies. You probably will need to rebuild the transformer to get to 100khz. Maybe you are not using a transformer, and then the diodes are critical.

RonSimpson
 

Thread Starter

Hellerx44

Joined Apr 6, 2021
11
21khz is just above TV frequencies. You probably will need to rebuild the transformer to get to 100khz. Maybe you are not using a transformer, and then the diodes are critical.

RonSimpson
[/QUOTE]
Im just using zvs drive with a transformer, 30v 15 amp attached picture
 

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Papabravo

Joined Feb 24, 2006
19,595
Not failing, but for better functionality, and better results. For my particals accelerator project.
I meant that the existing selection of components is failing to meet the needs and requirements of your project. I did not mean that any componets you are using are actually failing to perform their specified function after being placed in service.
 

ronsimpson

Joined Oct 7, 2019
2,535
I don't have enough information.
That flyback transformer is probably designed for VGA 31.5khz. I don't really know which version you have.
Do you have the schematic of the red board in the photo?
edited----
Why do you want to run faster?
 

Janis59

Joined Aug 21, 2017
1,537
In most cases the ferrite core is the weakest element determining the max frequency. When it becomes overstepped, the voltage decreases. Thus, You have measured that your ferrite is designed for 21 kHz max. :) :)

Just take the better core (or organize coreless (air-core) transformer what easily allows to get anything between 3 and 6 MHz. But at more over those frequency starts problems about too slow power MOSFETs, however having few solutions up to 50...100 MHz. Over that freq may add the price some 3 zeros and take off some 3 zeros from power.
 
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