127
Circuit 102:
Charge circuit for AA batteries
Setup information
Install the transistor, the three diodes and the two resistors as shown in
Fig. 2.102.
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 BAT85
Schottky diode,
1 x 22
Ω
resistor,
1 x 4.7 k
Ω
resistor,
1 x breadboard, 1 x 9V
battery with clip con-
nector, 1 x AA battery
holder
Fig. 2.102:
Charge circuit for
AA batteries
Experiment
This experiment shows where else you could deploy a constant current source in a meaningful way. We
already came across this circuit several times in connection with supplying power to LEDs. But charging a
NiMH-AA battery using a 9V battery does not really make sense. If needed, you could power the circuit by a
9V DC power adapter. Constant charging current of about 20 mA is flowing in our circuit here.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.102.
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...
