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9 volt power supply from 120 volts AC

fixit7

Member
I would like to build a regulated 9 volt D.C. power supply that uses 115 v AC to supply low current circuits.

The plan I found uses a power transformer, voltage regulator, zener diode, transistor, and some capacitors.

My wall transformer puts out .6 amp which is more than I need. There is no way to take it apart without destroying it.

It weighs 44 grams( or about 2 ounces) so I am wondering if it uses a power transformer.
 

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ChrisP58

Well-Known Member
I would like to build a regulated 9 volt D.C. power supply that uses 115 v AC to supply low current circuits.

The plan I found uses a power transformer, voltage regulator, zener diode, transistor, and some capacitors.

My wall transformer puts out .6 amp which is more than I need. There is no way to take it apart without destroying it.

It weighs 44 grams( or about 2 ounces) so I am wondering if it uses a power transformer?

You say that you "would like to build."
Is that because you think you have a need for something other than what you have? Or that you're looking for a learning experience?
 

gophert

Well-Known Member
Most Helpful Member
I would like to build a regulated 9 volt D.C. power supply that uses 115 v AC to supply low current circuits.

The plan I found uses a power transformer, voltage regulator, zener diode, transistor, and some capacitors.

My wall transformer puts out .6 amp which is more than I need. There is no way to take it apart without destroying it.

It weighs 44 grams( or about 2 ounces) so I am wondering if it uses a power transformer?

Please load photos directly to this site - click the paper clip button at the bottom left of the text box you type in for each post. I don't do DropBox.
 

ChrisP58

Well-Known Member
The power supply in your first post is a flyback type, high frequency switch mode supply. It does use a transformer, although in a flyback converter it's more accurately called a coupled inductor.

But that transformer can only be used as part of a circuit like the one that it's in. You couldn't use it as a normal line frequency transformer.
 

fixit7

Member
I am using it with my laser alarm circuit.

Weight is not an issue. Using a power transformer along with zeners, etc. would be fine.

I am using 2 AAs with my laser.

I am also wanting to power it from an AC source.
 

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