Maker Pro
Maker Pro

Negative Voltage Offline SMPS

Good day everyone,

Can anyone shed some light on making a negative DC voltage
mains(offline) SMPS?

I've designed quite a few offline switchers, but i've always created
+9 or +12V DC with them. Now, I have a requirement for a -48V DC
Power supply that runs off of mains (65-280VAC) power. Incidently, I
need it to give me about 4A (200W).

I'm familiar with offline switchers, and I know the dangers and
precautions.

Any help greatly appreciated!
Ben
 
Oh, Also, Space is tight. All of the offline switchers I've made in
the past have been somewhat physically large - can anyone give me some
tips for lowering the size of the footprint (Especially the HEIGHT).

Thanks again!
Ben
 
J

John Popelish

Jan 1, 1970
0
Good day everyone,

Can anyone shed some light on making a negative DC voltage
mains(offline) SMPS?

I've designed quite a few offline switchers, but i've always created
+9 or +12V DC with them. Now, I have a requirement for a -48V DC
Power supply that runs off of mains (65-280VAC) power. Incidently, I
need it to give me about 4A (200W).

I'm familiar with offline switchers, and I know the dangers and
precautions.

Any help greatly appreciated!
Ben

Design an isolated +48 volt supply, and use the positive
terminal as the common.
 
J

John Larkin

Jan 1, 1970
0
Good day everyone,

Can anyone shed some light on making a negative DC voltage
mains(offline) SMPS?

I've designed quite a few offline switchers, but i've always created
+9 or +12V DC with them. Now, I have a requirement for a -48V DC
Power supply that runs off of mains (65-280VAC) power. Incidently, I
need it to give me about 4A (200W).

I'm familiar with offline switchers, and I know the dangers and
precautions.

Any help greatly appreciated!
Ben


Umm, reverse the outputs?

John
 
E

Eeyore

Jan 1, 1970
0
Good day everyone,

Can anyone shed some light on making a negative DC voltage
mains(offline) SMPS?

I've designed quite a few offline switchers, but i've always created
+9 or +12V DC with them. Now, I have a requirement for a -48V DC
Power supply that runs off of mains (65-280VAC) power. Incidently, I
need it to give me about 4A (200W).

I'm familiar with offline switchers, and I know the dangers and
precautions.

Any help greatly appreciated!

ALL power supplies can be negative ones by connecting the '+' output to
ground.

Graham
 
E

Eeyore

Jan 1, 1970
0
Oh, Also, Space is tight. All of the offline switchers I've made in
the past have been somewhat physically large - can anyone give me some
tips for lowering the size of the footprint (Especially the HEIGHT).

Use low profile components maye ?

Surely you could have thought that one through ?

Higher switching frequencies reduces the size on many of the components
required too.

Graham
 
Top