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24-30v dc power supply schematic

C

chas

Jan 1, 1970
0
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
.. . . in advance to one and all. . .thanks. .. chas.
 
R

Rick

Jan 1, 1970
0
John Fields said:
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.

---
View using a fixed-pitch font:


+-[BFD>]----------+-->OUT+
MAINS>-----+ +-+ |
BFT | | +-[<BFD]-+--------|-->OUT-
\ P||S | |
R||E +-[BFC+]-+
I||C | |
| | +-[<BFD]-+ |
MAINS>-----+ +-+ |
+-[BFD>]----------+

BFT:
http://www.signaltransformer.com/sites/all/pdf/Rectifiers.pdf

BFC:
http://www.cde.com/catalogs/CGS.pdf

BFD:
http://www.vishay.com/docs/88612/gbpc12.pdf

For high current designs a full wave using a center tap transformer is more
efficient, it makes better use of the iron in the transformer and you only
have one diode drop.

http://www.hammondmfg.com/pdf/5c007.pdf
 
J

Jamie

Jan 1, 1970
0
chas said:
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.

Let me get this correct here, you'd be happy with a 24V AC or
20v DC supply?


Jamie
 
C

chas

Jan 1, 1970
0
120 v AC imput and either 24 or 30 v DC output. Need higher output amps for
the furnace.
******************************************
 
C

chas

Jan 1, 1970
0
I'm at a loss on how to view this.
************************************
John Fields said:
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.

---
View using a fixed-pitch font:


+-[BFD>]----------+-->OUT+
MAINS>-----+ +-+ |
BFT | | +-[<BFD]-+--------|-->OUT-
\ P||S | |
R||E +-[BFC+]-+
I||C | |
| | +-[<BFD]-+ |
MAINS>-----+ +-+ |
+-[BFD>]----------+

BFT:
http://www.signaltransformer.com/sites/all/pdf/Rectifiers.pdf

BFC:
http://www.cde.com/catalogs/CGS.pdf

BFD:
http://www.vishay.com/docs/88612/gbpc12.pdf
 
C

Cydrome Leader

Jan 1, 1970
0
chas said:
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.

you're going to make an induction furnace, but need help with the brute
force power supply?

a plain bridge rectifier and some giant caps is probably fine for what you
need. something around 20VAC from the transformer will be about right.
 
P

P E Schoen

Jan 1, 1970
0
"chas" wrote in message
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.

Since you only need about 300 watts you might be able to use the 12 VDC from
a couple of old computer power supplies, in series. A 400W supply usually
has 12V at 15 amps or more. You may even be able to hack it to get what you
need with one unit, and if you can use the frequency of the supply for the
induction furnace, you may be able to tap off before the output rectifier
and use it directly on your induction coil.
http://www.mpja.com/Dual-250Watt-Reundant-Computer-Power-Supply/productinfo/17094+PS/
(12V 14A, $10)
http://www.mpja.com/650Watt-ATX-Echo-Star-Computer-Power-Supply/productinfo/17980+PS/
(12V 22A, $16)

You can also get single output switching power supplies for 15 amps or more:
http://www.mpja.com/12V-17A-Phihong-Power-Supply/productinfo/18091+PS/ ($15)

Paul
 
J

Jamie

Jan 1, 1970
0
P said:
"chas" wrote in message


Since you only need about 300 watts you might be able to use the 12 VDC
from a couple of old computer power supplies, in series. A 400W supply
usually has 12V at 15 amps or more. You may even be able to hack it to
get what you need with one unit, and if you can use the frequency of the
supply for the induction furnace, you may be able to tap off before the
output rectifier and use it directly on your induction coil.
http://www.mpja.com/Dual-250Watt-Reundant-Computer-Power-Supply/productinfo/17094+PS/
(12V 14A, $10)
http://www.mpja.com/650Watt-ATX-Echo-Star-Computer-Power-Supply/productinfo/17980+PS/
(12V 22A, $16)

You can also get single output switching power supplies for 15 amps or
more:
http://www.mpja.com/12V-17A-Phihong-Power-Supply/productinfo/18091+PS/
($15)

Paul
actually, I was thinking he could gets his hands on a 24 volt charger
from an auto parts store.

I have a large garage charger I gutted out and made a heavy duty 13.8
volt supply to test run 12 volt auto equipment.. I got large caps in
there filling the hole and a soft start. N channel power mosfets sinking
the (-) side output through an inductor to switch mode regulate it.

Works a treat, the caps are in 2 stages, one set before the switch and
another set after.

I figure even if it fets shorted, the full output isn't that much
higher, some equipment should handle it. ;)

Jamie
 
L

Les Cargill

Jan 1, 1970
0
John said:
John Fields said:
I need a schematic for a non regulated 24 or 20v dc power supply.
I will be running high amps (15?) for a homebuilt induction furnace.
. . . in advance to one and all. . .thanks. .. chas.


---
View using a fixed-pitch font:


+-[BFD>]----------+-->OUT+
MAINS>-----+ +-+ |
BFT | | +-[<BFD]-+--------|-->OUT-
\ P||S | |
R||E +-[BFC+]-+
I||C | |
| | +-[<BFD]-+ |
MAINS>-----+ +-+ |
+-[BFD>]----------+

BFT:
http://www.signaltransformer.com/sites/all/pdf/Rectifiers.pdf

BFC:
http://www.cde.com/catalogs/CGS.pdf

BFD:
http://www.vishay.com/docs/88612/gbpc12.pdf

For high current designs a full wave using a center tap transformer is more
efficient, it makes better use of the iron in the transformer and you only
have one diode drop.

---
I disagree.

With a bridge you're using all of the secondary all of the time, while
with FWCT you're using half of the secondary half of the time and the
other half of the secondary the other half of the time.

Also, FWCT takes twice the number of turns on the secondary and the
rectifiers have to stand off twice the reverse voltage.


That's what I'd always heard. You need center tap only if you
need output balanced about zero. It's also easier to filter the
output from the bridge with a solid ground reference.
 
J

Jasen Betts

Jan 1, 1970
0
"chas" wrote in message

Since you only need about 300 watts you might be able to use the 12 VDC from
a couple of old computer power supplies, in series.

that only wrks if you plug one of them into an isolating transformer.
 
W

whit3rd

Jan 1, 1970
0
I need a schematic for a non regulated 24 or 20v dc power supply.

I will be running high amps (15?) for a homebuilt induction furnace.

An easy option is two car batteries in series, with a couple of
chargers attached. If the induction furnace only operates for a
few minutes at a time, you can switch the batteries from series to
parallel and charge 'em offline.

Anything DC has to be filtered, if not regulated, and 15A of ripple
current is going to require some thought. Car batteries might
be overkill, but as long as the problem gets dead...

If you decide to get a regulated supply, there's surplus options. Consider:

<http://www.mpja.com/24V-125A-Hengfu-Power-Supply/productinfo/16489+PS/>
 
P

Phil Allison

Jan 1, 1970
0
"Rick"
For high current designs a full wave using a center tap transformer is
more efficient, it makes better use of the iron in the transformer ...

** That is 100% WRONG !!!!!!


** The link is full of damn silly errors, shame on Hammond.

A full wave bridge plus filter cap is the most efficient by far.

And to a close approximation, peak DC and average DC are the SAME !!



.... Phil
 
P

P E Schoen

Jan 1, 1970
0
"Michael A. Terrell" wrote in message
P E Schoen wrote:
Bad idea. The negative is tied to the case, and the power line neutral.

The negative MAY be connected to the case, but certainly not to the power
line neutral. So you may be able to remove the case ground connection, or
just float the second supply case 12VDC above the other. Here is a schematic
of a 300W ATX supply showing the separate grounds:
http://www.smpspowersupply.com/ATX_power_supply_schematic.pdf

Paul
 
P

P E Schoen

Jan 1, 1970
0
"P E Schoen" wrote in message
The negative MAY be connected to the case, but certainly not to the power
line neutral. So you may be able to remove the case ground connection, or
just float the second supply case 12VDC above the other. Here is a
schematic of a 300W ATX supply showing the separate grounds:
http://www.smpspowersupply.com/ATX_power_supply_schematic.pdf

Here is an article about using two server PSUs for 24 VDC:
https://sites.google.com/site/tjinguytech/my-projects/diy-24v-47a

And here is a good article about using components from a PSU to build your
own, with high efficiency synchronous rectifiers:
http://www.qrp4u.de/docs/en/smps_new/index.htm

Paul
 
C

Cydrome Leader

Jan 1, 1970
0
Phil Allison said:
"Rick"


** That is 100% WRONG !!!!!!



** The link is full of damn silly errors, shame on Hammond.

A full wave bridge plus filter cap is the most efficient by far.

that depends on the voltage you want from the power supply. If you want a
low voltage high current supply, a bridge rectifier can be a poor choice.
And to a close approximation, peak DC and average DC are the SAME !!

that's if there's no ripple. They never defined it, so yeah you could
question the pdf.
 
P

Phil Allison

Jan 1, 1970
0
"Cydrome Leader"
Phil Allison

that depends on the voltage you want from the power supply.


** Nonsense - a bridge rectifier always uses the transformer more
efficiently.

If you want a
low voltage high current supply, a bridge rectifier can be a poor choice.


** ROTFL !!

THREE completely undefined and unsupported claims, what rubbish !!!



that's if there's no ripple.


** Try reading the whole sentence - piss head.

What a posturing fuckwit.



..... Phil
 
P

Phil Allison

Jan 1, 1970
0
"Jamie" = radio ham moron: Maynard A. Philbrook



** **** off and die

- you stinking pile of AUTISTIC septic shit.
 
J

Jamie

Jan 1, 1970
0
Phil said:
"Cydrome Leader"




** Nonsense - a bridge rectifier always uses the transformer more
efficiently.

You're slipping again! It seems like it is becoming a habit lately.

I won't go into the obvious reasons why, you seem to be inadequate
lately to understand much, your responses show it.



** ROTFL !!

THREE completely undefined and unsupported claims, what rubbish !!!

Perfect example of your dissolving brain cells.
** Try reading the whole sentence - piss head.

What a posturing fuckwit.



.... Phil

Get off the sauce, it's effecting your judgment.

And I thought the drugs here in the states were better, maybe I was
wrong about that one ? Actually, I was mistaken.

Jamie
 
J

Jamie

Jan 1, 1970
0
Phil said:
"Jamie" = radio ham moron: Maynard A. Philbrook



** **** off and die

- you stinking pile of AUTISTIC septic shit.

You just can't handle it when you slip up.. That's too bad too,
I was hoping you'd stick your neck out even future, but you
have chosen the usual imodium.

Stick your nose in google some more, maybe you'll get it
correct the next time..

Jamie
 
C

Cydrome Leader

Jan 1, 1970
0
Phil Allison said:
"Cydrome Leader"


** Nonsense - a bridge rectifier always uses the transformer more
efficiently.

I want to hear more about how you'd make a 2.2 volt 100 amp linear power
supply with a bridge rectifier, and what sort of single digit efficiency
you'd expect to get from it.
 
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