Positive to Negative Voltage Converter

Description

Voltage Converters Kit offers the advantage of allowing negative voltage to be combined with the original positive supply to simulate a dual supply. In this Positive to Negative Voltage Converter, the first block is the power supply in which the input is 230V AC and is step down using the transformer (12-0-12). With the 12V ac input, the bridge diode produces pulsating DC voltage. This DC voltage is filtered through the capacitor to remove the ripples. This filtered DC is fed to the 7805 regulators for +5v regulated output.

The Positive to Negative Voltage Converter is based on timer IC NE555. The NE555 is wired as an astable multivibrator operating at around 1 kHz. The square wave output is available at pin no 3 of the IC. During the positive half of the square wave, capacitor C4 (22Uf) charges through the diode (E1) 1N4001. When the output of IC is at zero the C4 (22Uf) discharges through the diode (E1) 1N4001 and the capacitor (C5) 100uF gets charged.

As a result of this Electronics Power Tool, the voltage at the junction of the anode of (E2) 1N4001 and cathode of (C5) 100uF will be always negative with respect to the ground.