Simple Switching Circuit with 555 for Negative Supply

This shematic is called Simple Switching Circuit with 555 for Negative Supply. In principle, the core of this series are located in the IC 555. If you need a negative for the op-amp or just need a negative bias voltage while operating from a single supply voltage (battery operation for example), this circuit helps provide a negative supply for you. Circuit that is based on the cost of 555 pump driven by the circuit switching. Here is a schematic diagram.



If you use 9V positive supply then the negative output will be around 8 volt, or if you use 12 volt positive supply the you’ll get around 11Volt negative supply. 100mA current could be drawn safely from the negative voltage output. This is enough for most op-amp or other small signal application. PCB to the scheme below.