Power Circuit. 1

Hi,

I am unsure what you mean.

Do you want to build a circuit to control mains power (light dimmers , motor controllers to name just 2 examples)

Or do you want to run an appliance which would normally be run on batteries from a mains supply.

I suspect its the latter given that you included the word batteries with your post.

Well the circuit you need for that is ..... Hold on its a bit like the question how long is a piece of string. Before you can design or build such a device you would need to provide most of the following information.

1. What's the mains voltage at your local (110/220 or both)
2. What voltage do you require at the output
3. What is the current requirement of the device your powering.
4. Do you need AC or DC out
5. Is efficiency a requirement
6. Is size of the supply a factor.
7. Is the supply for a device that has bare metal or can come in contact with yourself (Headphones I'm thinking here)
8. What's your experience in building mains circuits.

All of these would tell whether you need a SMPS or Linear regulated type device.

I'm guessing here (and forgive me if I'm wrong) but DC power supplies are basic stuff when it comes to electronic work. Is electronics new to you?. I only ask, because if it is and you have an interest I would stay away from mains connected projects, and just buy an multivoltage adapter for your current requirements. They're only a few bucks and if you get a good one they're fused & may have double insulated transformers.

If I'm way off the mark then post the specs & I'm sure I may have a design for you.

regards

Suggestion: There are various books listing circuit for devices that may be built by hobbyists. Some books were published by TAB Books, Blue Ridge Summit, PA 17214, USA, others appeared in books similar to:
John Markus, "Electronic Circuits Manual," McGraw-Hill Book Co., 1971
However, as the previous posting suggests this approach is more time consuming and more expensive than to buy the adapters or power supplies commercially off the shelf.
Also, there is a potential hazard since the sold product usually comply with industry standards, e.g. Underwriters Laboratories (UL) so that they are considered safe. If you produce some power supply and someone else gets hurt, you could be held liable for the injury or electrocution. Therefore, you have to exercise the utmost caution.