I designed this unit for my 2001 model Suzuki GSX-R1000 and was designed to be minimally intrusive to the bikes electrical system-- only a battery connection is needed. The system monitors battery voltage and two mercury switches (X and Y planes). It doesn't immobilise engine. The unit uses a 12V/20mA/105dB piezo speaker with a inbuilt oscillator. The sound from it is very loud.

Unit draws about 10mA idle.. and when alarm goes off, uses about 30mA. This will be improved in future iterations. Also, case design will be improved. That external capacitor you see is because I didn't have room to fit it inside the box ;(. I'm also toying with the idea of fitting a mobile phone to the unit so that the system can ring you when it's being pinched. I want to find out if it's viable to implement an engine immobiliser.. for that I need to get hold of a schematic for my bike.

At this stage, it's really only a prototype... however, a useful (working) prototype I might add ! ;).