Car Alarm Arming Horn Beep Canceller

Schematic

Parts

Part Total Qty. Description Substitutions C1 1 0.01uF Ceramic Disc Capacitor C2 1 100uF 35V Electrolytic Capacitor R1 1 1K 1/4W Resistor R2 1 10K 1/4W Resistor R3 1 15K 1/4W Resistor R4 1 470 Ohm 1/4W Resistor D1, D3, D4 3 1N4004 Rectifier Diode D2 1 Red LED U1 1 555 Timer IC K1 1 SPST 12V Automotive Relay MISC 1 Board, Wire, Socket For U1, Case Notes This circuit is by bob and was originally posted to the forum as Need Circuit Project to Improve Remote Car Alarm.