Transformerless voltage converter. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Voltage converters, rectifiers, inverters
Comments on the article
Effective control of the varicaps of a VHF FM unit requires a power supply with a voltage of 2-4 times greater than that. which is commonly used in transistor radios.
In the model of the "Stern automatic" radio receiver (manufactured in the GDR), a transformerless device is used instead of a traditional generator with a step-up transformer to obtain such a voltage.
It is (see figure) a simple pulse generator based on transistors of various structures with a voltage multiplier.
The device converts the battery voltage of 9 V into a stabilized voltage of 21 V, which is then used to control the varicaps in the VHF FM unit.
In the voltage converter, instead of the SC206 transistor, you can use any transistor of the KT315 series. Diodes of the D1 series can be used as diodes D4-D9, and instead of D5, two zener diodes D814V connected in series.
Literature
- "Radio fernsehen eleklranik" (GDR), 1975, No. 15
Publication: N. Bolshakov, rf.atnn.ru
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