Wireless portable unit Adaptable with most internal combustion engine vehicles Circuit Diagram Parts: R1,R2,R19 1K 1/4W Resistors R3-R6,R13,R17 100K 1/4W Resistors R7,R15 1M 1/4W Resistors R8 50K 1/2W Trimmer Cermet R9 470R 1/4W Resistor R10 470K 1/4W Resistor R11 100K 1/2W Trimmer Cermet (see notes) R12 220K 1/4W Resistor (see notes) R14,R16 68K 1/4W Resistors R18 22K 1/4W Resistor R20 150R 1/4W Resistor (see notes) C1,C7 100µF 25V Electrolytic Capacitors C2,C3 330nF 63V Polyester Capacitors C4-C6 4µ7 25V Electrolytic Capacitors D1,D5 Red LEDs 3 or 5mm. D2,D3 1N4148 75V 150mA Diodes D4 BZX79C7V5 7.5V 500mW Zener Diode IC1 CA3140 or TL061 Op-amp IC IC2 4069 Hex Inverter IC IC3 4098 or 4528 Dual Monostable Multivibrator IC Q1,Q2 BC238 25V 100mA NPN Transistors L1 10mH miniature Inductor (see notes) BZ1 Piezo sounder (incorporating 3KHz oscillator) SW1 SPST Slider Switch B1 9V PP3 Battery (see notes) Clip for PP3 Battery Device Purpose: This circuit has been designed t...