Maker Factory ELECTRONICS EXPERIMENTS BOX Manual page 233

Experiment
This circuit delivers constant voltage at the output, even if battery voltage is fluctuating. It behaves just like
a properly wired Zener diode. In our case, we have an output voltage of 4 V. The battery voltage may fluctu-
ate between 7V and 9V.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.209.
Circuit 210: Discreet 5.2V Zener diode
Setup information
Install the two transistors and the seven resistors as shown in Fig. 2.210. The ten jumper wires come next.
Check the placement on the board again and only then connect the battery.
Experiment
This circuit delivers constant voltage at the output, even if battery voltage is fluctuating. It behaves just
like a properly wired Zener diode. In our case, we have an output voltage of 5.2 V. The battery voltage may
fluctuate between 7V and 9V.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.210.
Components required:
1 x 2N3904 transistor,
1 x 2N3906 transistor,
2 x 1 kΩ resistors,
2 x 10 kΩ resistors,
3 x 22 kΩ resistors,
1 x breadboard, 1 x 9V bat-
tery with clip connector
Fig. 2.210: Discreet 5.2V Zener
diode
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