Maker Pro
Login Join Maker Pro
Or sign in with

Menu

Connect With Us

Network

Maker Pro

Power Supply Help and Advice Sought!

S

SME

Dear Group,

I have schematic that I found on the web it was designed for US 120V mains.
What
do I need to do to convert it for UK 240V?

Also the two capacitors C1,C2 200V 4700uf are very expensive is there anyway
to get the same effect by using smaller cheaper ones ie in parallel or
serial ?

I attempted to draw the schematic with text characters but it looked like a
mess!
Please follow the link below to view the schematic.

http://paragon.chill.net/

Thanks For Your Help.
Steve
 
T

tempus fugit

What is it a power supply for? Looking at it, I can't see how it would
deliver the voltages it's suggesting. Also, is that supposed to be connected
to 350v at the top, or the voltage measured there?
 
C

Chris Oates

tempus fugit said:
What is it a power supply for? Looking at it, I can't see how it would
deliver the voltages it's suggesting. Also, is that supposed to be connected
to 350v at the top, or the voltage measured there?
Click to expand...

I think he's trying to make a voltage doubler
by copying the C values from a very low voltage
circuit - C is massively too big
 
S

SME

Yeah that's exactly what I am trying to achieve but I am beginning to think
that maybe 350VDC is a little to large.
I am also concerned with the hazard as believe it or not I do value my life!
;-)

I have a thread running on sci.electronics.design that is a little more
mature than this so it may be worth taking a look there!

Thanks for your replies thus far...

Steve.
 
D

Dimitrij Klingbeil

SME said:
I have schematic that I found on the web it was designed for US 120V mains.
What
do I need to do to convert it for UK 240V?

Also the two capacitors C1,C2 200V 4700uf are very expensive is there anyway
to get the same effect by using smaller cheaper ones ie in parallel or
serial ?

I attempted to draw the schematic with text characters but it looked like a
mess!
Please follow the link below to view the schematic.

http://paragon.chill.net/
Click to expand...

To convert your device from 120 to 240V operation you need to remove the
connection between the 'central tap' of the 2 capacitors and NEUT, i.e. NEUT
will only be connected to the rectifier, but no longer to the caps. That's
all. The caps' central connection will no longer be used. This was a common
design in AT power supplies some years ago, there was a 120/240V swich that
allowed 120V operation when closed and 240V when open. Many nowadays' PS
adjust themselves to the voltage automatically, but that's another story.
The caps will be expensive indeed, but everything depends on whether you
really need that thing to deliver 7.5A (or this like). If only 2A or so is
needed, use smaller caps. Note that if the device is to be operated from
ONLY 240V and does not need the ability to be switched back to 120V, you
need only one cap (2.4mFx400V in this case). Values like 4.7mF (or even
2.4mF at high voltages) are best obtained from multiple caps in parallel. In
any case, could you please tell us what this is gonna be used in, it will
make your situation a lot easier for us to analyze.

Dimitrij
 
R

Ross Mac

SME said:
Dear Group,

I have schematic that I found on the web it was designed for US 120V mains.
What
do I need to do to convert it for UK 240V?

Also the two capacitors C1,C2 200V 4700uf are very expensive is there anyway
to get the same effect by using smaller cheaper ones ie in parallel or
serial ?

I attempted to draw the schematic with text characters but it looked like a
mess!
Please follow the link below to view the schematic.

http://paragon.chill.net/

Thanks For Your Help.
Steve
Click to expand...
I agree with Chris, that's a typical voltage doubler circuit. If you want
"that" circuit you will need a 2:1 stepdown xformer....An additional expen$e
! Have you tried electronic surplus? You might find a deal there on all the
parts... Here is a place I use.... http://www.alltronics.com ... If you
buy the caps there be sure to check the date codes. Call them with a parts
list. The xformer will have to be around 2.5 to 3 KVA dependant on how much
of that 20 amps you really need and make sure to fuse it. If you can't find
the parts there try a google search...good luck on your project...Ross
 
S

SME

Dimitrij thanks very much for your reply...

Take a look at the following links this is where I got the schematic from
but this was only a small part of it.
This should explain what I am enquiring about better than I could here ;-)
You may also wish to take a look at the group sci.electronics.design as
there is a duplicate thread running there that has had a little more
replies.

http://dave.golfbuddys.com/hvguy/new/2500Wheater.htm
http://dave.golfbuddys.com/hvguy/new/2500Wheater_2.htm

Thanks Again,
Steve.
 
R

Ross Mac

SME said:
Dimitrij thanks very much for your reply...

Take a look at the following links this is where I got the schematic from
but this was only a small part of it.
This should explain what I am enquiring about better than I could here ;-)
You may also wish to take a look at the group sci.electronics.design as
there is a duplicate thread running there that has had a little more
replies.

http://dave.golfbuddys.com/hvguy/new/2500Wheater.htm
http://dave.golfbuddys.com/hvguy/new/2500Wheater_2.htm

Thanks Again,
Steve.

parallel.
Click to expand...
Cross post it next time!!
 
S

SME

Sorry to sound a little dumb but is cross posting achieved by sending it to
both groups at the same time?
ie
Newsgroups sci.electronics.basics;sci.electronics.design
Regards
Steve.
 
R

Ross Mac

SME said:
Sorry to sound a little dumb but is cross posting achieved by sending it to
both groups at the same time?
ie
Newsgroups sci.electronics.basics;sci.electronics.design
Regards
Steve.


parallel nowadays'
Click to expand...
Yes...just post it to the groups you would like a response from...this way
the posts go everyone and eliminates duplication.....Ross
 
You must log in or register to reply here.

Similar threads

D
Power supply help for air purifier
2
Replies
32
Views
2K
diode
D
M
Maytronics Power Supply not work. Help please.
Replies
2
Views
692
martrader17
M
T
15 pin Sub-D power supply/control help
Replies
6
Views
1K
(*steve*)
(*steve*)
V
help with eprom programmer power supply.
Replies
4
Views
699
vari21
V
K
Help Identifying a transformer and it's use from a PC power supply
Replies
10
Views
1K
ColKlonk
C
Top