In this tutorial, we will demonstrate a circuit of a Negative Voltage Generator using a 555 timer IC. Most of the time we need a negative voltage for some applications in electronics. Using a negative supply source is not reliable when it’s needed for low current applications. There are options available commercially but they are usually expensive or not readily available when you need them. Therefore, this circuit can be used as a negative supply, it is for all practical purposes.
This circuit generates negative power from a positive power supply. It is a simple circuit that can be easily adapted to various requirements. We are using one of the most popular and versatile IC i.e., 555 timer IC and a few other components.
Hardware Components
The following components are required to make Negative Voltage Generator Circuit
| S.no | Components | Value | Qty |
|---|---|---|---|
| 1. | IC | NE555 Timer | 1 |
| 2. | Breadboard | – | 1 |
| 3. | Diode | 1N4007 | 2 |
| 4. | Resistor | 5.1K, 33K Var | 1, 1 |
| 5. | Ceramic Capacitor | 0.022µF | 1 |
| 6. | Electrolytic Capacitor | 22µF, 33µF | 1, 1 |
| 7. | Connecting Wires | – | 1 |
| 8. | Batteries | 12V | 1 |
NE555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
Negative Voltage Generator Circuit
Working Explanation
This circuit is simple and can be operated at 5-15 volts of input voltage. The 555 timer IC is working as a negative voltage generator. After receiving power, the IC will generate a square wave from its output pin (Pin 3). This cycle of the square wave will be generating both positive and negative voltage. When there is a positive voltage the 22uF capacitor connected at the output pin of the IC will be charged through 1N4002 Diode D1 and no positive voltage goes to output. When there is a negative voltage then this capacitor discharges through other diode D2 and the 33uF capacitor charges and the output will provide negative voltage ranging from -3 volts to -13 volts.
You can also use this circuit for a dual power supply.
Applications and Uses
It is used for circuits where only positive supply is available or for RS-232-type interfaces, other than that it is used for various electronic circuits and devices.
