I'll try to furnish some information on the feedback subject:
Timm didn't provide any because it's not needed. I worked for a few years at
Tadiran electronics on the GRC-106 SSB radio. It had a SMPMS power supply
providing 2400 VDC from the 28 VDC primary power and it didn't have any
control loop either. That one operated at about 500 Hz.
Provided the transformer has a reasonable internal resistance, dynamic
regulation is more dependent on the output capacitance than anything else.
The benefit of switchers is that the transformer is based on about
6volts/turn: this gives a primary of about 2x40 turns and a secondary of
about 400 turns. It all amounts to very much shorter wires than in a
conventional power supply, so the droop should be much less than with a
conventional transformer.
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
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Paul Decker
Sent: Wednesday, May 20, 2009 11:27 PM
To: KD7QAE
Cc: amps@contesting.com
Subject: Re: [Amps] Source wanted for HV switch-mode power supply
Hi Tomm ,
Actually, it is funny you say that. I wanted to redraw the schematic into
my schematic program so it could do autoroute and pcb layout. When I did, I
found that my pcb layout was limited to 100 pads, which forced me to break
the schematic up into individual boards, so that work is already done ;)
The original pwm module is about 1"x1", it goes to a signal amplifier board,
which goes to the h-bridge. My H-Bridge board is a bit weird on the layout
because I used some leftover heat sinks and kept the leftover parts
placement. After the HV transformer there is the HV rectifier board.
Tim's original design doesn't provide any feedback but that could easily be
added and the little pwm module be replaced to allow for a feedback control
of some type. For me, the HV transformer was the hardest part and I'm
still not convinced I like what I have implemented, it may get some changes.
As far as a kit, who knows, but I'll try to put design files up on my web
page this weekend and if people want them, they can pull them from there.
73 for now,
Paul, kg7hf
----- Original Message -----
From: "KD7QAE" <KD7QAE@ ARRL .NET>
To: "Paul Decker" kg7hf@comcast.net
Once you get it working, it would be straight forward to lay out a few
PC boards so others could do what amounts to a kit build.
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|