A Converter without a transformer

Not open for further replies.


Joined Jan 29, 2010
Is it possible to have a 110 v AC to 12 v DC converter circuit without using a transformer?
It is possible to do that conversion, but I would only recommend using that method providing that the PSU is sealed in order to prevent a possible electric shock as there is NO isolation from the 110V supply.

How is the PSU going to be used.?



Joined Oct 18, 2012
The danger involved is why it is against the terms of service to discuss their implementation.

But, yes, it is possible.

Thread Starter


Joined Feb 28, 2014
I have recently opened the internal circuit of an LED bulb which works with 110 v AC to drive 4 LEDs which they need 12 v DC. This circuit includes only 2 resistors, a capacitor, and an Ic probably a Diode bridge. I' m wondering how it may work without a transformer!!?


Joined Oct 15, 2009
Just go to google and search "transformerless power supply"..

This post is going to be locked soon because the owners of this site have decided that it is against the rules to discuss these types of power supplies on this forum because it can be very dangerous for inexperienced users..


Joined Jan 29, 2010
hi Mahmoudtak,
If you have to ask how a transformer-less, non mains isolated converter works, my advice would be not to attempt to copy/build or repair this type of unit.

The low cost of a transformer isolated 'wall wart' or equivalent type is well worth the investment.

And never throw away the transformer when you take apart say old amplifiers and other stuff.

Over the years i've built up a large inventory of various transformers ranging from 15VA up to 1.5kVA.


Joined Oct 2, 2009
Please note that discussion of transfomer-less power supplies is prohibited on All About Circuits.

This thread is against AAC forum rules, Chapter 6, as seen here:

6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:
• Any kind of over-unity devices and systems
• Automotive modifications
• Devices designed to electrocute or shock another person
• LEDs to mains
• Phone jammers
• Rail guns and high-energy projectile devices
Transformer-less power supplies
This can be found in our Terms of Service (ToS).

There are other sites that may be able to answer your questions.
Not open for further replies.