# minature transformers wanted

#### jack0987

##### Member
I have a small project that needs both 5vdc and 12vdc.
I have a dual voltage power supply but it is way to big to fit in the box.
I can get a 5vdc usb charger that is about 1 inch square easy enough,
but finding a 12vdc one about the same size is not so easy.

So, just build a little one perhaps?
Finding a very small transformers for a dollar or two
with a 120vac input and outputs of about 7vac and 15vac is proving not to be so easy either.
Yes, there are deals out there, but will I be able to get another one 6 months from now and
another one a year from now.

Anyone know of any?
For lack of a better idea at this time,
miniature transformers wanted.

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#### ronsimpson

##### Well-Known Member
A 5VDC USB power supply probably makes more power than you need. I would use a PWM IC to boost the 5V to 12V. In my case I would build it but here is one built.
Boost Supply $6 (that's 3 supplies for$6)

Here is another one. Have not looked at it. link

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#### ronsimpson

##### Well-Known Member
Or a very different way.
Get a 120Vac to 12Vdc supply and then add a small 12V to 5V buck power supply. (looks much like the above supply, but works differently)

#### dr pepper

##### Well-Known Member
You can get leads, a usb connector one end with a 5v to 12v inverter inside, and a dc barrel jack at t'other, a little doctoring would give you a 12v and a 5v o/p.

#### Pommie

##### Well-Known Member
I'd go with the 12V wall wart and 5V regulator. What current is required?

Mike.

#### jack0987

##### Member
Thanks for the replies.

I'd go with the 12V wall wart and 5V regulator. What current is required?

Mike.
Not much current is needed. At present, I think I'd go your way. Thanks, Mike.

#### rjenkinsgb

##### Well-Known Member
Thanks. I like this idea. Meanwell also makes a 5vdc version.
Thinking I can use one of each and just connect the grounds together.
Does that seem workable?
Yes, certainly - that would work fine.
The only reason for suggesting a 5V regulator with the 12V one was to save cost and space, if the power requirements were low enough.

#### jack0987

##### Member
Yes, certainly - that would work fine.
The only reason for suggesting a 5V regulator with the 12V one was to save cost and space, if the power requirements were low enough.
These are working great for me. Found out, they also make a 3.3vdc version which will work even better.
They make other voltages as well.