1200V amplifier

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People,

I want to build a sor of amplifier which can make 0 to 1200V output out of 0 to 5V input (may also be inverted).

It has to be a lineair control. It also has to be in SMD. Many transistors or FETs can't go further than Vce and Vbe of 200/300V, so I have to make something which can handle the 1200V.

Anyone has an idea?! Thanks!

Martijn;)
 
good luck finding SMD resistors for KV operations. KV transformers are also special beasts -- once you go over 600V the wire and between-layer insulation becomes quite specialized and expensive. I don't know what the situation is on that side of the Atlantic, over here HV transformers are relatively easy to obtain from military surplus outlets and ham radio flea-markets.

in fact, one of the easiest ways of implementing this design is to regulate the primary side of a transformer, picking up the error signal from the secondary side -- think of it as a linear supply using switching power control loop principles. instead of controlling the duty cycle of a switch, control the amplitude of a primary side amplifier -- you can opto-couple the feedback control just as in a SMPS.
 
jackinnj said:
good luck finding SMD resistors for KV operations. KV transformers are also special beasts -- once you go over 600V the wire and between-layer insulation becomes quite specialized and expensive. I don't know what the situation is on that side of the Atlantic, over here HV transformers are relatively easy to obtain from military surplus outlets and ham radio flea-markets.

in fact, one of the easiest ways of implementing this design is to regulate the primary side of a transformer, picking up the error signal from the secondary side -- think of it as a linear supply using switching power control loop principles. instead of controlling the duty cycle of a switch, control the amplitude of a primary side amplifier -- you can opto-couple the feedback control just as in a SMPS.



An easy way would be using a standard audio power amp and have it drive a step-up transformer that can handle the voltage levels. That gives you galvanic isolation, low price (an LM3886 would be great for this) and level control.

Jan Didden
 
janneman said:
Just thought of something: this 1200V is that peak-to-peak or RMS or what? if it is p-p and balanced you can use a tube power amp and take the output from the primary of the output xformer.

Jan Didden

that's what we used "in my youth" when doing Electron Spin Resonance experiments -- seems like a shame to have used a McIntosh amplifier, but what the heck, the U.S. Navy was paying for it.
 
jackinnj said:


that's what we used "in my youth" when doing Electron Spin Resonance experiments -- seems like a shame to have used a McIntosh amplifier, but what the heck, the U.S. Navy was paying for it.

My dissertation work involved the use of B&K 4003s to measure infrared spectra. For some reason or other, those mikes never seemd to be around unless I was physically in the lab.

Why was the Navy doing ESR?
 
My dissertation work involved the use of B&K 4003s to measure infrared spectra.

How do you measure heat waves with a microphone? Infrasound would be more to the liking of those mics. We hung some 4006's in the chimney of a factory to measure the spectra for sound control. Didn't last long... And don't try to measure at -50°C with B&K stuff, the preamps have a heater that put out enough heat for a room (well, out measuring chamber anyway). Had to disconnect that. First class stuff that B&K gear.
 
It's actually a pretty nifty technique. You modulate the incident light, then the material surface alternately heats and cools, causing the boundary layer of air (or other gas) to expand and contract. That produces sound.

The advantage is that you can get absorption spectra from "difficult" samples, things that are tough to measure via transmission or reflection.

The B&K mikes are wonderful. Not that I would have ever stooped so low as to commandeer them when I wanted to record something...
 
SY said:


My dissertation work involved the use of B&K 4003s to measure infrared spectra. For some reason or other, those mikes never seemd to be around unless I was physically in the lab.

Why was the Navy doing ESR?

It had to do with super-conductivity of copper-gold alloys, the Navy had a research institute which farmed out projects. Working in physics research convinced me that there were more fun things to do in life.
 
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Joined 2012
People,

I want to build a sor of amplifier which can make 0 to 1200V output out of 0 to 5V input (may also be inverted).

It has to be a lineair control. It also has to be in SMD. Many transistors or FETs can't go further than Vce and Vbe of 200/300V, so I have to make something which can handle the 1200V.

Anyone has an idea?! Thanks!

Martijn;)

You might search for electrostatic headphone amplifer circuits. Cant use smd at high voltage.
 
I do not know what about the SMD-mounted amplifier, but in such an amplifier circuit for 1500 - 2000 watts I have. It is only necessary to take good kandensatory on the power supply and very powerful diode bridges. I think that the power amplifier does not make sense to make a pulsed power supply due to strong fluctuations at maximum capacity. This amplifier ripple current at full power for about 10 - 15 amps. With such a supply voltage and currents of these seems to me that the surface mount assembly, it is not realistic at least.
An externally hosted image should be here but it was not working when we last tested it.
 
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