Category: Electronics Projects

My electronics projects

Running American C7/C9 Christmas lights (110V) directly on a 220V supply

Whew, long time without another post – it’s been a busy time, glad to get back to blogging.
This post is going to explain the basics of using American 110V Christmas lights on a 220V electrical supply, by splitting the light string in half and putting them in series instead of using a dedicated voltage converter.

Last Christmas I was in the U.S. and, as a fan of large bulb C7 Christmas lights, I picked up a nice old set for a grand total of $9.49.
fullsizerender-12-1
img_1855-1

They looked and worked great in the hotel room, I just needed to modify them to work on a 220V supply that we use in South Africa (and most of the rest of the world). I could have used a voltage converter but this string uses over 100W, a large transformer would be needed ($$$).
A cheap and easy solution is just to split the string in half, and have both sections connected in series; each section would receive 110V.

Temperature-controlled Peltier Mini Fridge

main
UPDATE: Project featured on Hackaday.com! See here
I recently finished up on my Peltier Mini fridge project, and it works great!
It can cool down whatever you want that’ll fit in it — six 330ml cans for example — and can get down to –2.1°C!
Watch the video for a full description and how it works. I gotta say, it’s really cool, excuse the pun!

Playing video and other fun things on a Nokia 3310 LCD with Arduino

The Nokia 3310 LCD is well known in the electronics community. It is a monochrome graphics LCD with a resolution of 84×48 and was originally used in the Nokia 3110 and 5110 handsets, and is relatively old (1998), but in my opinion it is brilliant for its price.

I purchased mine on Dealextreme for only $5.60 (link to the product page here), which is a very good price considering what is possible with this display. It came in a nice breakout board so it can be used directly on a breadboard.

If you remove the casing on the breakout board, you will find out that the display looks just like a piece of glass, and has a PCD8544 controller chip embedded inside it.

This controller has an easy to use SPI protocol and handles all the hard work of driving this display (multiplexing, generating bias voltages, ect.).
Driving the display is relatively easy with any microcontroller. However, it runs on and uses 3.3V logic, so you would need level shifters to shift the voltage down.