Telephone call Voice Changer

Voice manipulation device specially intended for props, 9V Battery operation Although this kind of voice effect can be obtained by means ...

Room Noise Detector

One LED monitors three levels: 50, 70 & 85 dB, Useful to detect too noisy environments This circuit is intended to signal, through a f...

White LED Lamp

Nowadays you can buy white LEDs, which emit quite a bit of light. They are so bright that you shouldn’t look directly at them. They are sti...

You Have Mail!

If your letterbox is some distance from your house, you will find a monitoring device useful to indicate when new post has arrived. This ca...

The Home-Brew Spot Welder

Spot welder used to weld two pieces of metal together. Welding is achieved using sour modern that passes throught metal pieces and wel...