Very High Voltage Amp Output Stage

rtarbell · 11th May 2006, 04:41 AM

I have seen a couple of companies online that produce very high voltage amplifiers (on the order of +/- 1kV output swing).

One such company is Trek Inc.

www.Trekinc.com

In their brochure, they give a block diagram as to how their product works, and if I may summarize it, the output stage is a bunch of cascoded mosfets (with a very high voltage bipolar supply) with each mosfet gate driven from an optoisolator.

==> I thought optoisolators were nonlinear; how can an output stage be driven from an optoisolator with the signal integrity still preserved?

djk · 11th May 2006, 07:27 AM

What use is it for you?

Their biggest model can only put out 400mA at ±1KV.

"Large Signal Bandwidth (2% Distortion)
DC to greater than 2.5 kHz."

"Small Signal Bandwidth (-3dB)
DC to greater than 20 kHz."

Model 30/20A
High-Voltage Amplifier

I use an AR Inc unit at work that can do ±15KV, but at only 3.5mA

There are some class D amps with IGBTs that can do ±1KV at several KW, maybe that's what you need?

powerbecker · 11th May 2006, 07:56 PM

snip: rtarbell
==> I thought optoisolators were nonlinear; how can an output stage be driven from an optoisolator with the signal integrity still preserved?

Simply use feedback!
More serious is that they are noisy!

snip: djk
Their biggest model can only put out 400mA at ±1KV.

Trek is THE company for high voltage amps:
http://www.trekinc.com/products/+5kV.asp
http://www.trekinc.com/products/5-80.asp
for example!

Regards
Heinz!

gerhard · 11th May 2006, 09:48 PM

Quote:

Originally posted by powerbecker
snip: rtarbell
==> I thought optoisolators were nonlinear; how can an output stage be driven from an optoisolator with the signal integrity still preserved?

Simply use feedback!

That moves the problem from the forward to the feedback path only.

regards, Gerhard

Eva · 11th May 2006, 09:52 PM

Check out size and weight of model 5/80 (the one from second link)

powerbecker · 11th May 2006, 11:07 PM

[QUOTE]Originally posted by gerhard
[B]

That moves the problem from the forward to the feedback path only.

No, because the FB-path is DC-coupled the whole amp get much more linear, but the noise is still there.

Regards
Heinz!

gerhard · 11th May 2006, 11:25 PM

Quote:

Originally posted by powerbecker

No, because the FB-path is DC-coupled the whole amp get much more linear, but the noise is still there.
[/B]

If a dc connection is ok for the feedback path, why do you
need an opto coupler for the forward path in the first place?

regards, Gerhard

powerbecker · 11th May 2006, 11:47 PM

Quote:

Originally posted by gerhard

If a dc connection is ok for the feedback path, why do you
need an opto coupler for the forward path in the first place?

regards, Gerhard

Gerhard,

I don´t need it but they use it

On the other hand if noise is not the issue I think also that this is a simple way to steer a long chain of c 1200V N-igbts/mosfets EQUALLY at high slewrate!

Regards
Heinz!

CBS240 · 12th May 2006, 12:18 AM

electrocuted by the output of an audio amp....what a way to check out, eh?

Just hope it's a tune you like

rtarbell · 13th May 2006, 05:02 AM

I know that these high voltage amps are not exactly audio quality, I was just wondering how to drive an output stage using optoisolators. How would they be connected?

11th May 2006, 04:41 AM	#1
rtarbell diyAudio Member Join Date: Sep 2005	Very High Voltage Amp Output Stage I have seen a couple of companies online that produce very high voltage amplifiers (on the order of +/- 1kV output swing). One such company is Trek Inc. www.Trekinc.com In their brochure, they give a block diagram as to how their product works, and if I may summarize it, the output stage is a bunch of cascoded mosfets (with a very high voltage bipolar supply) with each mosfet gate driven from an optoisolator. ==> I thought optoisolators were nonlinear; how can an output stage be driven from an optoisolator with the signal integrity still preserved?

11th May 2006, 09:52 PM	#5
Eva diyAudio Member Join Date: Oct 2003 Location: Near the sea	Check out size and weight of model 5/80 (the one from second link) __________________ I use to feel like the small child in The Emperor's New Clothes tale

12th May 2006, 12:18 AM	#9
CBS240 diyAudio Member Join Date: Aug 2005 Location: K-town	electrocuted by the output of an audio amp....what a way to check out, eh? Just hope it's a tune you like __________________ All the trouble I've ever been in started out as fun......

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
output stage with high impedance	alex0	Solid State	54	1st November 2011 05:40 AM
Differential output stage: cap voltage?	Klimon	Tubes / Valves	2	23rd May 2009 11:44 PM
Tube output stage for voltage DAC ?	mgm31	Digital Source	9	5th February 2008 08:22 AM
Which high power CCS for output stage?	andyjevans	Tubes / Valves	12	24th November 2005 11:45 AM
High voltage transistors for VAS stage	rtarbell	Parts	4	15th November 2005 12:13 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

11th May 2006, 07:27 AM	#2
djk diyAudio Member Join Date: Feb 2001 Location: USA	What use is it for you? Their biggest model can only put out 400mA at ±1KV. "Large Signal Bandwidth (2% Distortion) DC to greater than 2.5 kHz." "Small Signal Bandwidth (-3dB) DC to greater than 20 kHz." Model 30/20A High-Voltage Amplifier I use an AR Inc unit at work that can do ±15KV, but at only 3.5mA There are some class D amps with IGBTs that can do ±1KV at several KW, maybe that's what you need?

11th May 2006, 07:56 PM	#3
powerbecker diyAudio Member Join Date: Dec 2004 Location: Berlin	snip: rtarbell ==> I thought optoisolators were nonlinear; how can an output stage be driven from an optoisolator with the signal integrity still preserved? Simply use feedback! More serious is that they are noisy! snip: djk Their biggest model can only put out 400mA at ±1KV. Trek is THE company for high voltage amps: http://www.trekinc.com/products/+5kV.asp http://www.trekinc.com/products/5-80.asp for example! Regards Heinz!

11th May 2006, 11:07 PM	#6
powerbecker diyAudio Member Join Date: Dec 2004 Location: Berlin	[QUOTE]Originally posted by gerhard [B] That moves the problem from the forward to the feedback path only. No, because the FB-path is DC-coupled the whole amp get much more linear, but the noise is still there. Regards Heinz!

13th May 2006, 05:02 AM	#10
rtarbell diyAudio Member Join Date: Sep 2005	I know that these high voltage amps are not exactly audio quality, I was just wondering how to drive an output stage using optoisolators. How would they be connected?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read