252
Fig. 3.25:
Circuit
25: Automatic
solar light with
battery
Fig. 3.26:
Circuit
26: 2 seconds
switch-off delay
Circuit 26 – 28: Electrolytic capacitor C1 charges fully, when button S1 is activated. R2 and R3 are used to
discharge the e-cap. For as long as the capacitor voltage remains above the threshold voltage of the transis-
tors, T1 and T2 remain switched through and LED1 is lit. If the electrolytic voltage drops below the value of
the threshold voltage, the transistors block, LED1 turns off.
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...
