

Quartz Watch Tester
We can check any mechanical watch by hear tick – tick sound whether it is working or not but to check any electronics quartz watch which does not have second needle is quite tedious work because no sound is produce. To check this type of watch a circuit “Quartz Watch Tester” is used.
Circuit Description
The circuit of quartz watch tester utilize a amplifier IC a coil of few turn and a transistor. The pulse produced by watch is pick–up by coil of 30 – 50 turns made from 42 SWG copper wire over 45mm * 4 mm iron nail. The pulse from coli is given to base of transistor T1 through capacitor C9. Transistor T1 is used as pre – amplifier. The output of pre – amplifier i.e. from collector of transistor T1 is given to input pin 8 of IC1 through capacitor C7. IC1 (TBA810) is a audio amplifier IC which further amplify the pulse up to desired level and fed to loudspeaker through capacitor C6 for output.
PARTS LIST
Resistors (all ¼-watt, ± 5% Carbon)
R1, R2 = 100 Ω
R3 = 100 KΩ
R4 = 2.2 KΩ
R5 = 390 KΩ
R6 = 470 KΩ
Capacitors
C1 = 220 µF/10V
C2 = 0.001 µF
C3 = 0.005 µF
C4, C5, C7 = 100 µF/16V
C6, C10 = 1000 µF/16V
C8 = 33 µF/16V
C9 = 1 µF/50V
Semiconductors
IC1 = TBA810 (audio amplifier)
T1 = BC147
Miscellaneous
SW1 = ON/Off switch
LS1 = 8 Ω loudspeaker
L1 = 30 – 50 turns of 42 swg copper wire over 45mm*4mm iron nail