The DIY Electronic Siren circuit described here can create three different US-style siren sounds: DIY police, DIY ambulance and fire engine. The desired sound can be selected using switch S1. The ...

Zetex Semiconductors have a siren driver IC Type ZSD100 available that is suitable for use in alarm systems for cars and model craft. With the addition of only a few components as shown in the diagram ...

Ed Nauman owns a house situated just uphill from some city-owned property that provides his yard with an endless supply of pocket gophers. He has tried to defeat them from digging up his yard, but ...