Dear Friends,
For a long time, I'm thinking to regulate the B+ voltage of mine vaccum tube amplifier.
I found many solutions but this is able to 400v ~ 350v in the input. I need a regulator to put on input 500v and in the output 400v.
I passed some time searching for some transistors which can put 800v or more on Vce. But It is very difficult to found.
Anybody have a solution to this?
Best Regards,
Felipe
For a long time, I'm thinking to regulate the B+ voltage of mine vaccum tube amplifier.
I found many solutions but this is able to 400v ~ 350v in the input. I need a regulator to put on input 500v and in the output 400v.
I passed some time searching for some transistors which can put 800v or more on Vce. But It is very difficult to found.
Anybody have a solution to this?
Best Regards,
Felipe
Re: high volt reg
High voltage MOSFETs are not very hard to find. Maybe use two along with an opamp circuit for control?
Microwave ovens are not regulated, except the really fancy ones with continuous power control, but those regulate with high frequency PWM on the primary side just like modern power supplies.eatitdean said:
High voltage MOSFETs are not very hard to find. Maybe use two along with an opamp circuit for control?
A horizontal drive transistor is rated for high voltages, but they're optimized for switching.mod_evil said:
Have a resistor from drain to gate to bias the MOSFET on, a zener diode from gate to source to limit bias voltage, then the drain of another MOSFET connects to the gate of the first through a resistor. The second MOSFET is connected to an opamp that compares the voltage from a voltage divider on the output to a reference.
Interestingly enough, a similar circuit was designed by some HVAC engineers in the drive circuit for a piezoelectric expansion valve, which requires a varying bias voltage of up to hundreds of volts, although practically no current. From what I could remember, there was a small high voltage MOSFET, a small high voltage bipolar transistor, along with lots of resistors and a diode or two in the high voltage circuit. There was also a low voltage opamp for closing the loop and it accepts a signal from a DAC to allow digital control of the output voltage.
Star,
It can be simple... We needn't DAC. We can make a simple regulator. But the problem with the simple is the High Voltage.
How the Op-Amp can compare high voltages and correct it? Your idea is so good, but I think the Operational Amplifier isn't able to this high voltages.
I'm searching... And I see this schematic.
See this:
http://www.duncanamps.com/technical/mosfet.html
How can I change the ouput voltage in this regulator? Can this regulator able to have in the output 350v or 300v?
Best Regards,
Felipe Navarro
It can be simple... We needn't DAC. We can make a simple regulator. But the problem with the simple is the High Voltage.
How the Op-Amp can compare high voltages and correct it? Your idea is so good, but I think the Operational Amplifier isn't able to this high voltages.
I'm searching... And I see this schematic.
See this:
http://www.duncanamps.com/technical/mosfet.html
How can I change the ouput voltage in this regulator? Can this regulator able to have in the output 350v or 300v?
Best Regards,
Felipe Navarro
mod_evil said:
An externally hosted image should be here but it was not working when we last tested it.
I'll guess the picture only is an example becasuse 7805 is very unsuitable to use like this. For instance it doesn't like zero load!
IGBT has high Vce, Checked anyone?
What about this tube super regulator?
IGBT has high Vce, Checked anyone?
What about this tube super regulator?
Dear Peranders and Star
I'm not thinking to use a Tube Regulator Circuit like the "Tube Super Regulator", because this is will be more 3 heathers to power up. And We can make a simple circuit to regulate this.
About the Star882 regulator circuit, I think in place of 7805 we can put a REF01 or another good reference of voltage.
About the IBGT, I never used one before. Do you have any idea to use a IBGT here?
Best Regards,
Felipe Navarro
I'm not thinking to use a Tube Regulator Circuit like the "Tube Super Regulator", because this is will be more 3 heathers to power up. And We can make a simple circuit to regulate this.
About the Star882 regulator circuit, I think in place of 7805 we can put a REF01 or another good reference of voltage.
About the IBGT, I never used one before. Do you have any idea to use a IBGT here?
Best Regards,
Felipe Navarro
Hi Mod_evil,
Check out the "Swenson" regulator on my web page. To make a long story short several years ago I started down a path that led to a high performance high voltage CCS. John Swenson developed a HV regulator by adding an error amplifier to the CCS core turning it into a nice linear regulator. A couple of weeks ago I built up the regulator circuit and ran some performance tests. Based on the tests some circuit values were changed to maximize performance. I also added some protection circuitry and a current limit stage.
Gary
Gary P's DIY page
Check out the "Swenson" regulator on my web page. To make a long story short several years ago I started down a path that led to a high performance high voltage CCS. John Swenson developed a HV regulator by adding an error amplifier to the CCS core turning it into a nice linear regulator. A couple of weeks ago I built up the regulator circuit and ran some performance tests. Based on the tests some circuit values were changed to maximize performance. I also added some protection circuitry and a current limit stage.
Gary
Gary P's DIY page
Dear Friends,
Today I'm seeing on my deposit and I have many 2sc3678. This is a High Voltage NPN transistor.
Do they have any idea to use this?
Dear Gary,
I looked on your website the Swenson Regulator, I think its very good. I looked on farnell for FQAF11N90 and LND150. No matchs.
Can I use another High Voltage Mosfet? Do you know a more commom?
Best Regards,
Felipe Navarro
Today I'm seeing on my deposit and I have many 2sc3678. This is a High Voltage NPN transistor.
Do they have any idea to use this?
Dear Gary,
I looked on your website the Swenson Regulator, I think its very good. I looked on farnell for FQAF11N90 and LND150. No matchs.
Can I use another High Voltage Mosfet? Do you know a more commom?
Best Regards,
Felipe Navarro
Hi Felipe,
For the pass element (Q2) just about any MOSFET that meets the voltage, current, and power requirements should work. The value of R15 may need to be changed for the best compromise of performance and circuit stability.
The SuperTex LND150 is a unique part and has no cross reference that I'm aware of.
Gary
For the pass element (Q2) just about any MOSFET that meets the voltage, current, and power requirements should work. The value of R15 may need to be changed for the best compromise of performance and circuit stability.
The SuperTex LND150 is a unique part and has no cross reference that I'm aware of.
Gary
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