Door Alarm

• R1 1M 1/4W Resistor
• R2 3K3 1 or 2W Resistor (See Notes)
• R3 10K 1/2W Trimmer Cermet (See Notes)
• R4 33K 1/4W Resistor
• R5 150K 1/4W Resistor
• R6 2K2 1/4W Resistor
• R7 22K 1/4W Resistor
• R8 4K7 1/4W Resistor
• C1,C2 10nF 63V Ceramic or Polyester Capacitors
• C3 10pF 63V Ceramic Capacitor
• C4,C6 100nF 63V Ceramic or Polyester Capacitors
• C5 2µ2 25V Electrolytic Capacitor
• C7 100µF 25V Electrolytic Capacitor
• D1,D2,D4 1N4148 75V 150mA Diodes
• D3 5 or 3mm. Red LED
• Q1,Q2,Q3,Q5 BC547 45V 100mA NPN Transistors
• Q4 BC557 45V 100mA PNP Transistor
• L1 (See Notes)
• L2 10mH miniature Inductor
• Hook (See Notes)
• BZ1 Piezo sounder (incorporating 3KHz oscillator)
• SW1,SW2 SPST miniature Slider Switches
• B1 9V PP3 Battery
• Clip for PP3 Battery