87
Circuit 62:
DC-DC converter 9V to 75V
Setup information
Install the two transistors, the diode and the three resistors as shown in
Fig. 2.62
. Next install the ceramic
capacitor, the electrolytic capacitor and the fixed value inductor. It is important to ensure that the electro-
lytic capacitor has a dielectric strength of 160V.
The thirteen jumper wires come next. Check the placement on the board again and only then connect the
battery.
Components required:
2 x 2N3904 transistors,
1 x 1N4148 silicon diode,
1 x red LED, 1 x 1 k
Ω
resis-
tor, 1 x 10 k
Ω
resistor,
1 x 22 k
Ω
resistor,
1 x 220 μH fixed induct-
ance, 1 x 1 nF ceramic
capacitor, 1 x 10 μF/160V
electrolytic capacitor,
1 x breadboard,
1 x 9V battery with clip
connector
Fig. 2.62:
DC-DC converter 9V
to 75V
Experiment
This circuit is used to convert a larger DC voltage to a smaller one. The two transistors ensure that strong
current pulses are sent through the fixed value inductor. This results in a very high induction voltage, which
charges the electrolytic capacitor C2 after rectification with D1. There then the highly-transformed output
voltage is available. In our present circuitry the unregulated output voltage is at 75V. The voltage is detected
by a multimeter in a measuring range of 200V.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.62.
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...
