Switcher with 480VAC single phase input

[Guy Macon]

I am looking for an off-the-shelf 24VDC 25A switching power supply
that will run off a 480VAC single phase input. Does anyone know
of a vendor who makes such a beast? Just a name; I can do the
searching given a hint as to what direction to go. Thanks!

Guy Macon
<http://www.guymacon.com/>

 

[Paul E. Schoen]

I am looking for an off-the-shelf 24VDC 25A switching power supply
that will run off a 480VAC single phase input. Does anyone know
of a vendor who makes such a beast? Just a name; I can do the
searching given a hint as to what direction to go. Thanks!

Guy Macon
<http://www.guymacon.com/>

I have looked without success for such an animal. One idea I considered was
using the 277 VAC L-N voltage, which may be close enough to the usual 264
VAC maximum, or a small buck transformer could bring it down.

Another possibility is to run two 240 VAC power supplies in series. You
would probably need to add a voltage divider (maybe a 480 VAC CT
autotransformer) to make sure the two supplies have about equal input
voltages, and the outputs would probably need to be each 12 VDC and also
wired in series to present an equal load.

A third possibility is a phase fired SCR voltage controller, but it would
cause some high current transients into the input capacitors, so a series
inductor may be needed to reduce the current spikes.

A custom design may be the only "clean" option.

Paul

 

[Homer J Simpson]

I am looking for an off-the-shelf 24VDC 25A switching power supply
that will run off a 480VAC single phase input. Does anyone know
of a vendor who makes such a beast? Just a name; I can do the
searching given a hint as to what direction to go. Thanks!

You can't transform down to 120 or 24 VAC first?

 

[Terry Given]

I am looking for an off-the-shelf 24VDC 25A switching power supply
that will run off a 480VAC single phase input. Does anyone know
of a vendor who makes such a beast? Just a name; I can do the
searching given a hint as to what direction to go. Thanks!

Guy Macon

Hi Guy,

you might have to modify one.

Get a SMPS with a voltage doubler configuration for 110/220V operation.

That way you can replace the two caps (usually 220V) with 400V caps, and
use a suitably rated rectifier.

Make sure it uses a FET for the primary switch, ideally in a TO-247
package (they pretty much all do)

Then remove the FET and replace it with a BU508 (or any Horizontal
output transistor).

Lift the emitter, and place a small LV FET in series with it (D--> E,
S--> current sense resistor).

connect the FET gate to the original gate output.

lift the base, and place a 1W resistor to the smps supply, with an
antiparallel diode (Kathode to supply, Anode to base). choose the
resistor based on min Hfe.

Voila, you now have an emitter-switched bipolar, which will eat up to 1500V.

If there is sufficient duty cycle available, you wont need to vandalise
the transformer at all.

you will probably need to mangle the startup supply (higher R), and also
the clamp network (diode voltage rating)

Cheers
Terry

 

[jasen]

I have looked without success for such an animal. One idea I considered was
using the 277 VAC L-N voltage, which may be close enough to the usual 264
VAC maximum, or a small buck transformer could bring it down.

Another possibility is to run two 240 VAC power supplies in series. You
would probably need to add a voltage divider (maybe a 480 VAC CT
autotransformer) to make sure the two supplies have about equal input
voltages, and the outputs would probably need to be each 12 VDC and also
wired in series to present an equal load.

that could get kind of exciting with a pair of switchers with inputs in
series, isolation could be an issue too.



Bye.
Jasen

 

[jasen]

I am looking for an off-the-shelf 24VDC 25A switching power supply
that will run off a 480VAC single phase input. Does anyone know
of a vendor who makes such a beast? Just a name; I can do the
searching given a hint as to what direction to go. Thanks!

a quick google search found me

"Cabur CSG30P" (340-550VAC in , 24V @ 30A out)

These are three-phase but will operate from 507-700VDC too.

So, for single phase operation you'll need to add a capacitor
and a rectifier.


Bye.
Jasen

 

[Guy Macon]

"Cabur CSG30P" (340-550VAC in , 24V @ 30A out)

These are three-phase but will operate from 507-700VDC too.

So, for single phase operation you'll need to add a capacitor
and a rectifier.

This is the solution I chose. Thanks, Jasen!

They cost $410.00 each and are available in the USA at:

AUTOMATION SYSTEMS INTERCONNECT, Inc.
P.O. Box 1230 - CARLISLE, PA 17013 - USA
Tel. +1 717 2495581 - Fax +1 717 2495542
E-mail: [email protected]
Internet: www.asi-ez.com
Contact: Mr. Mike Manning