User Tools

Site Tools

Translations of this page?:



The module creating a symmetrical power supply for analog constructions with operational amplifiers (e.g. SDRX01B receiver). The input voltage should be +12V or +5V and will be converted to -12V and +12V.

Construction solutions

Charge pump

One of the possibilities, how to create a negative voltage, is to use a charge pump. There already exist specialised integrated circuits suitable for this purpose.

Power inverter

One of the limitations of the charge pump is the impossibility to obtain larger supply currents. The problem can be solved using a transformer and electronic circuit, which convert the input DC voltage to AC. Given that the converted voltage can be of significantly higher frequency than the usual 50 Hz, thus the size of the transformer, having the same power output, can be much smaller. The higher frequency also allows to reduce the smoothing capacity values.

Moreover, in the case of input DC potential commuting sinusoidally on the transformer windings, the possibility of noise emission is considerably decreased compared to the conventional SMPS.

Another advantage in using the transformer is, that the output power supply can be galvanically isolated from the input power supply.

en/sympower.txt · Last modified: 2013/07/24 23:44 (external edit)