128
2.45 Battery discharger
Circuit 103:
Discharge circuit for AA batteries
Setup information
Install the transistor, the two diodes and the two resistors as shown in
Fig. 2.103.
Then install the three
jumper wires. Finally connect the AA battery holder Check the placement on the board again and only then
connect the battery.
Components required:
1 x 2N3904 transis-
tor, 2 x 1N4148 silicon
diodes, 1 x 10
Ω
resis-
tor, 1 x 4.7 k
Ω
resistor,
1 x breadboard, 1 x 9V
battery with clip con-
nector, 1 x AA battery
holder.
Fig. 2.103:
Discharge circuit
for AA batteries
Experiment
This experiment shows where else you could deploy a constant current source in a meaningful. We already
came across this circuit several times in connection with supplying power to LEDs. You should however,
fully discharge NiMH batteries every now and then. That is why a discharge circuit is very useful. Constant
discharge current of about 40 mA is flowing in our circuit here.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.103.
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...
