On Sep 15, 3:03*pm, Highland Ham wrote:
steve H wrote:
wrote:
On Sep 15, 12:57 pm, Highland Ham wrote:
wrote:

snip This thing seems to be regulated primarily by the input
CURRENT which
would be the same as power and David Smith said in his discription. I
think the answer to using it as a power supply is to turn it into a
VOLTAGE regulated power supply by taking a voltage sample off of the
HV transformer, possible by adding a couple of turns coil to the
transformer, and replacing the input from the current transformer with
this one. Naturally the inpit to IINDO may have to be suitably
modified also.
==========================================
You might consider taking a voltage sample by 'tapping' a low DC voltage
fraction from the HV output ,putting that into an opamp with adjustable
output.

You can see how this is done in an article *in QEX-July.August 1999
,pages 50-55. 'A regulated 2400 V power supply ' by VE6AXW

Frank *GM0CSZ / KN6WH

============================================== Thanks Frank, but I dont have QEX or access

Jimmie

======================================http://www.realhamradio.com/hvreg.pdf

for a schematic.

hth

Steve H

=================================
Indeed ,that's the one. *Tnx Steve for the interesting URL

Frank * GM0CSZ / KN6WH- Hide quoted text -

- Show quoted text -


Is there any more info on the circuit besides the schematic?

This looks like something I could build and I probably already have
most of the parts.


I see it uses SCRs for switching. I guess there is no problem with
latchup. I built a 400Hz inverter one time and it seemed to work for a
while until one day it latched up on me and smoked. I had been using
it to power some selsyn motors. Someone plugged a soldering iron into
the inverter and I think it was a little too much load. I guess that
is what I get for not labeling my outlets.

Jimmie

The designer of this power supply did something very wrong.
Using the safety/chassis ground as a power connection to
run 120V loads is dangerous. If you need to power 120V
loads run a neutral line or use a 240/120 transformer.

Safety ground should only be connected to the chassis,
faraday screens and Y-rated capacitors.

Neutral and safety ground eventually tie together so
it seems like an OK thing. It's not. It's a violation
of the NEC, any applicable safety standards and might
on the off chance cause serious injury or death.


==============http://www.realhamradio.com/hvreg.pdf

On Sep 21, 10:03*am, Grumpy The Mule wrote:
The designer of this power supply did something very wrong.
Using the safety/chassis ground as a power connection to
run 120V loads is dangerous. *If you need to power 120V
loads run a neutral line or use a 240/120 transformer.

Safety ground should only be connected to the chassis,
faraday screens and Y-rated capacitors.

Neutral and safety ground eventually tie together so
it seems like an OK thing. *It's not. *It's a violation
of the NEC, any applicable safety standards and might
on the off chance cause serious injury or death.



==============http://www.realhamradio.com/hvreg.pdf- Hide quoted text -

- Show quoted text -

Yeah its a fool killer, Did you notice how they develop the Vcc.
Im sure under the conditions
its designed to be used its safe enough but if you get enough
hams tinkering with it someone might get killed.
David Smith kind of backed out of the project because of this.

I got sidetracked on this project a bit remodeling my bathrooms
but while prowling through my storage shed(junk box) I came across an
old SMPS, it s rated 48 volts at 50 amps. I was going to build a
big FET amp around it but never did. The output of it is just
rectifiers and filters connected to the transformer. There
is a second winding that is rectified and appears to develop
feedback voltage. I was thinking of building a step up transformer
and connecting it back to back with the transformer on
this power supply. I was also having thoughts of just replacing the
transformer with one designed for HV.

On Sep 21, 10:03*am, Grumpy The Mule wrote:
The designer of this power supply did something very wrong.
Using the safety/chassis ground as a power connection to
run 120V loads is dangerous. *If you need to power 120V
loads run a neutral line or use a 240/120 transformer.

Safety ground should only be connected to the chassis,
faraday screens and Y-rated capacitors.

Neutral and safety ground eventually tie together so
it seems like an OK thing. *It's not. *It's a violation
of the NEC, any applicable safety standards and might
on the off chance cause serious injury or death.



==============http://www.realhamradio.com/hvreg.pdf- Hide quoted text -

- Show quoted text -

I never saw where the neutral and ground tied together. The closest
thing I could see was on the HV side of the transformer where one side
is tied to ground. This is OK. I did find in another service manual
where it warned about not having the mounting screws to the power
supply fastened tightly while servicing. Thats almost funny. Probably
a good idea to use this on a GFCI circuit.

Anyway I came across some 120/240 to 240/480 volt 2KVA transformers I
had. This got me thinking that it may be at lot of fun building a
switcher when you had 600VDC at a few amps to switch. Coming up with a
transformer may be fun.

Jimmie

I meant in this design...
http://www.realhamradio.com/hvreg.pdf

A safety ground connection is used for
120V loads because there's no neutral
taken from the AC line connection.

They should have used a four pole connector
and run a neutral as well as ground to the
power supply.

The ground and neutral are tied together
at your service entry.

You could connect two 120/240 transformers with
the primaries in parallel and the secondaries in
series. Then you'd have 480AC source which makes
a decent input to a doubler for about 1200VDC output.

There's nothing wrong with blood and thunder supplies
except the weight and the stored energy. If the parts
are available the cost factor might win out.


I never saw where the neutral and ground tied together. The closest
thing I could see was on the HV side of the transformer where one side
is tied to ground. This is OK. I did find in another service manual
where it warned about not having the mounting screws to the power
supply fastened tightly while servicing. Thats almost funny. Probably
a good idea to use this on a GFCI circuit.

Anyway I came across some 120/240 to 240/480 volt 2KVA transformers I
had. This got me thinking that it may be at lot of fun building a
switcher when you had 600VDC at a few amps to switch. Coming up with a
transformer may be fun.

Jimmie

On Sep 25, 7:38*pm, Grumpy The Mule wrote:
I meant in this design...http://www.realhamradio.com/hvreg.pdf

A safety ground connection is used for
120V loads because there's no neutral
taken from the AC line connection.

They should have used a four pole connector
and run a neutral as well as ground to the
power supply.

The ground and neutral are tied together
at your service entry.

You could connect two 120/240 transformers with
the primaries in parallel and the secondaries in
series. *Then you'd have 480AC source which makes
a decent input to a doubler for about 1200VDC output.

There's nothing wrong with blood and thunder supplies
except the weight and the stored energy. *If the parts
are available the cost factor might win out.



I never saw where the neutral and ground tied together. The closest
thing I could see was on the HV side of the transformer where one side
is tied to ground. This is OK. I did find in another service manual
where it warned about not having the mounting screws to the power
supply fastened tightly while servicing. Thats almost funny. Probably
a good idea to use this on a GFCI circuit.

Anyway I came across some 120/240 to 240/480 volt 2KVA transformers I
had. This got me thinking that it may be at lot of fun building a
switcher when you had 600VDC at a few amps to switch. Coming up with a
transformer may be fun.

Jimmie- Hide quoted text -

- Show quoted text -

I agree, I understand the commercial version of this has been
redesigned hopefully addressing some of the issues you mentioned.

I had given some thought to using the transformers as you discribe but
for right now my purpose is to learn abut and build a switching power
supply.

Jimmie