Projects in the January 2002 issue of EPE Magazine

PIC "Magick Musick"
You will delight and impress onlookers with your magical musical abilities, with a wave of the hand over our PIC-powered musical generator. Using the magical and mysterious powers of invisible beams to create melodies in thin air, you are guaranteed to enthrall and mystify your audience. Build our PIC Magick Musick unit today! Free source code available from our FTP site.

Time Delay Touch Switch
This self-contained mains switch will automatically turn off mains lights after a preset interval. Has no moving parts or exposed components, it's all controlled entirely by a fingertouch on the plastic faceplate. Easy to build.
Versatile Bench Power Supply
A PSU is an essential item of test gear for every workshop, but there is no need to buy expensive commercial units when you can construct this fully-specified mains-powered design for yourself instead. It provides variable voltages from 0-20V d.c. with current limiting on ranges of 100mA to 1 Amp. Twin moving-coil meter display.

Forever Flasher
Hard on the heels of our Perpetual Projects is this easy-to-build project, which we claim will flash an l.e.d. for 20 years or more. It uses the "free" energy derived from a short antenna, backed up by a 9V battery.

Teach-In 2002 (Part 3)
Continuing our ten part series examining the use of sensors to measure the environment. This month we look at humidity sensors, and in our Lab Work we offer some practical experiments that you can build to demonstrate the principles discussed.

Other features in this issue: New Technology Update describes "Bumpless Build-Up Layers", that squeeze more transistors into an i.c. chip; Circuit Surgery looks at the simple maths behind basic filter equations; Ingenuity Unlimited offers more readers' own circuits — all this and more in Everyday Practical Electronics magazine.