Posts Tagged ‘car alarm systems’



Speed Alarm For Cars

Tuesday, August 10th, 2010

In normal suburban driving you pass through so many different speed zones that it can be a nuisance having to switch speed settings. The speed display can also be a distraction. This circuit eliminates the display and the need for speed selection. Each time you exceed a particular speed setting (eg, 40km/h, 50km/h, etc), a [...]

Electronic car horn by NE556

Wednesday, June 10th, 2009

An LM556 dual oscillator/timer, U1, configured as a two-tone oscillator drives U2, a dual 4-watt amplifier. One of the oscillators, pins 1 to 6, contained in U1 produces the upper frequency signal of about 200 Hz, while the second oscillator, pins 8 to 13, provides the lower frequency signal of about 140Hz. Increase or decrease [...]

Car Burglar Alarm system with radio wave signal

Saturday, February 28th, 2009

When steal open automobile door relay K1 and K2 work make have voltage 12V give radio transmitter and origin sound part for mix radio waves steal will deaf anything sound. Because radio high frequency. But car owner will hear the sound , by take handbag very small radio, tune the frequency directly with the frequency [...]