Introduction: Plus-minus 5V Supply From 9V Battery (Part-1)

Hey everyone! I am back with another instructable.

Op-amps require a dual-polarity supply for proper operation. When working with battery supply, it becomes difficult to get a dual power supply for the op-amps. Presented here is a simple circuit that provides ±5V from a 9V battery.

Step 1: ​Required Hardware

The following components have been used:

1. X1 IC 7805 Voltage regulator.

2. X1 IC L7660 Voltage converter.

3. X1 9V battery

4. X1 Capacitor C1 470uF, 25V electrolytic

5. X1 Capacitor C2 2.2uF, 16V electrolytic.

6. X2 Capacitor C2 and C3 10uF 16V electrolytic.

7. X1 3 Pin connector CON2 (Output side)

8. X1 2 pin connector CON1 (Input side)

Step 2: Circuit Schematic & Working

The above image shows the circuit schematic of Plus-minus 5V Supply from 9V Battery Using Eagle software. It is built around 9V battery (BATT.1), voltage regulator IC 7805DT (IC1), CMOS voltage converter ICL7660CPA (IC2) and a few other components. Voltage regulator IC1 converts 9V battery input into regulated 5V. This 5V output from IC1 is given to pin 8 of IC2. IC2 and capacitors C3 and C4 form the voltage inverter section that converts +5V to -5V. Converted -5V supply is available at pin 5 of IC2. Converted ±5V supply is thus available at connector CON2.

Step 3: PCB Design

The image shows the circuit PCB Design of Plus-minus 5V Supply using Eagle software.

Parameter consideration for PCB design:

1. Trace width thickness is a minimum of 8 mil.

2. The gap between plane copper and copper trace is a minimum of 8 mil.

3. The gap between a trace to trace is a minimum of 8 mil.

4. Minimum drill size is 0.4 mm

5. All the tracks which have current path need thicker traces.

Step 4: Sending Gerber for Manufacturing

You can draw the PCB Schematic with any software as per your convenience. Here I have my own design and Gerber file attached. After you generate the Gerber file you can upload it or send it to the PCB manufacturer.

I usually prefer LIONCIRCUITS, they have low-cost prototyping services and I receive that boards in just 6 days. Their platform is very user-friendly, I just upload the Gerber files and rest all is taken care of by them. They provide the timely status of the project on their platform. They have made PCB manufacturing really easy for me.

Step 5: Waiting for Fabricated Boards

I will write part-2 of this inscrutable in the coming week after I receive the fabricated boards. Till then, stay tuned.