Broken Charger-connection Alert

Circuit diagram:

Parts:

R1______________10K  1/4W Resistor
R2_______________1K  1/4W Resistor
R3_______________1K  1/4W Resistor (Optional, see Notes)

D1,D2________1N4007 1000V 1A Diodes
D3______________LED  Red (Optional, see Notes)

Q1,Q2_________BC557   45V 100mA PNP Transistors

BZ1___________Piezo sounder (incorporating 3KHz oscillator)