[Amps] Source wanted for HV switch-mode power supply

[Alex]

One caveat, though!

In the original design, with no feedback, it was easy to add a filter to the
output.

With a closed loop system care is needed: the additional filter introduces
an additional pole which can create instability if not properly compensated!

Besides, I wouldn't go higher than about 100 kHz: it's not easy to find fast
rectifiers for that kind of voltage and they should be expensive! In my
opinion about 50-75 kHz should be high enough and much easier to build too.

Alex

 

  _____  

From: Paul Decker [mailto:kg7hf at comcast.net] 
Sent: Thursday, May 21, 2009 5:13 PM
To: Alex Eban
Cc: amps at contesting.com; KD7QAE
Subject: Re: [Amps] Source wanted for HV switch-mode power supply

 

The addition of a control loop would be helpful with the output filter
capacitors, since it will compensate dynamically for the 120Hz ripple on the
output, thus reducing the capacitance requirements on the output side.

>> Agreed.   The feedback likely isn't required, and since the output is at
200Khz, square wave, less output capacitance is required than a conventional
60/50 Hz design.  Simply increas the output capacitence, or even use a small
PI output filter.   Actually, the PI output filter for W9QQ's design was
mentioned in a follow on correction to the original article.

 

Paul Decker (KG7HF)


----- Original Message -----
From: "Alex Eban" <alexeban at gmail.com>
To: "Paul Decker" <kg7hf at comcast.net>, "KD7QAE" <KD7QAE at ARRL.NET>
Cc: amps at contesting.com
Sent: Thursday, May 21, 2009 5:11:51 AM GMT -05:00 US/Canada Eastern
Subject: RE: [Amps] Source wanted for HV switch-mode power supply

The addition of a control loop would be helpful with the output filter
capacitors, since it will compensate dynamically for the 120Hz ripple on the
output, thus reducing the capacitance requirements on the output side.
Ale        4Z5KS