Voltage Transformer

I first must confess, I'm a beginner hobbyist to electronics, and am always quite daunted walking through the components sections of electronics stores. So when it comes to selecting components for projects, I'm never truly certain I'm right. Nevertheless, I'm determined to make something more useful then flashing LEDs.

Basic Idea:
Use an RF transmitter, plugged into an AC outlet, to TX to an RF receiver. The receiver, also plugged in to an AC outlet, will engage, on a valid transmission, an EM relay sending the full current of the AC outlet through.

The RF module I've been looking at is a Ming TX-99 & RE-99. The VCC on the Ming boards are +5V @ 1.6 mA, but this needs to plug directly into an AC outlet without an external adapter.

Essentially, I don't really know how to design a transformer to convert the 120V AC to 5V DC to power the TX-99 & RE-99 boards, and do it compactly.

Any help would be greatly appreciated, and if nothing else, maybe just a link or two to some resources.

Many thanks!

buy a 5v adapter nd take the transformer outta it

You don't want to design the transformer, it a component that you buy. This URL may help: **broken link removed**

Hey, thanks for the link.. it looks like they go into detail, just what I need!

If I end up buying one though, don't they tend to be bulky? Or can you find compact ones for small projects?

Thanks again for your assistance!

I don't know what the electronics shops sell in the US, but in Australia they sell a wide range of transformers from small to large.

You need to calculate the power dissipated by your circuit and then buy a transformer that is large enough to handle it.

Note that transformers are specified in Volt Amps not Watts.

However, for your purpose, you can assume they are the same since the power factor should be small.

Len