Circuit to ensure balanced positive and negative voltage supply e.g. for operation amplifier

摘要

A voltage balancing circuit for a power supply with positive and negative rails for two loads in series, earthed at the centre node has a reference voltage source equal to half the total voltage of the supply, two equal capacitors (c1,c2) in series across the supply with the node between the capacitors earthed and a comparator (21) for the reference voltage against the voltage at this earthed node, giving an error signal. An amplifier (tr1) takes the error signal and acts to minimise it by supplying the required extra volts so that the positive rail voltage equals the inverse of the negative rail voltage.