318
Fig. 3.181:
Circuit 181: Simple 7.5V
battery monitor
Fig. 3.182:
Circuit 182: Simple
8.2V battery monitor
Circuit 181 and 182: Resistors R3 and R4 (R5) form a stable voltage divider. The lower battery voltage is fed
to the base of T2. At threshold, voltage is fed to base T2. T2 turns on, T1 is blocked, LED1 is off, if and for as
long threshold voltage is exceeded (battery voltage is sufficiently high). T2 opens, T1 is electrically conduc-
tive, if threshold voltage is undershot. LED1 is lit and signals that battery voltage is too low.
Summary of Contents for ELECTRONICS EXPERIMENTS BOX
Page 4: ......
Page 265: ...267 Fig 3 56 Cir cuit 56 Audio limiter Fig 3 57 Circuit 57 Amplifier for a storm detector...
Page 269: ...271 Fig 3 64 Circuit 64 Stabilizer for 1 9 V Fig 3 65 Circuit 65 Stabilizer for 2 5 V...
Page 275: ...277 Fig 3 80 Circuit 80 Quiztimer 30 seconds Fig 3 81 Circuit 81 Handy diode tester...
Page 315: ...317 Fig 3 179 Circuit 179 HF generator 150 kHz Fig 3 180 Circuit 180 HF generator 420 kHz...
