72
2.20 Variable Zener diode
Circuit 47:
Discreet 2.2V Zener diode
Setup information
Install the two transistors and the six resistors as shown in
Fig. 2.47.
The ten jumper wires come next. Last
but not least connect the moving-coil instrument. Check the placement on the board again and only then
connect the battery.
Components required:
1 x 2N3904 transistor,
1 x 2N3906 transistor,
2 x 1 k
Ω
resistors,
2 x 2.2 k
Ω
resistors,
1 x 10 k
Ω
resistor,
1 x 22 k
Ω
resistor,
1 x moving-coil instru-
ment, 1 x breadboard,
1 x 9V battery with clip
connector
Fig. 2.47:
Discreet 2.2V Zener
diode
Experiment
This circuit delivers constant voltage at the output – where the moving-coil instrument is connected – even
at fluctuating battery voltage. It behaves just like a connected Zener diode. Basically, Zener voltage is
defined by the value of the R2. In our case here, we have an output voltage of 2.2 V. The battery voltage may
fluctuate between 5V and 9V.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.47.
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...
