How to build Negative 5 V power supply circuit

Introduction 

Offlate electronics enthusiasts are asking reliable power supply circuit design on getting - (minus) negative power supply that too -5V circuit schematic. People need this special negative power supply for their specific electronics projects. As such a versatile and very simple negative voltage circuit can be assembled and put to use confidently. Such a circuit design is our hot discussion in this post exclusively discussed at length. 

IC7905

We are very familiar with IC7805 circuit designs which is commonly and popularly used for building +5V regulated power supply for many of our electronics projects. Especially +5V regulated power supply is very essential in digital electronics world. Most of us might have built circuits using IC7805 for +5V power supply. similarly IC 7905 is widely available and can be used to design to get negative power supply for specific circuit requirements. Electronics enthusiasts welcome such power supply as a resource for their work. 

IC 7905

IC 7905 is also a three terminal voltage regulator which works in power supply circuits. It gives current upto 1A output/. 

Output voltage is fixed -5V and regulated power supply

Input voltage is between -7V to -35V 

Output current upto 1 Ampere. 

Popular package TO-220

Internal overload and short circuit protection is available. 

Pin configuration 

The figure of IC 7905 and its pin connections are shown below.  

Pin1=Ground 

Pin2=Input

Pin3=Output 

Here, the ground is positive power supply. 

Typical power supply circuit design

The circuit schematic is very simple and straight forward. Pin 2 of the IC is fed with negative volt range from 7 to 35 volts from the bridge rectifier power source. Pin 1 is grounded. i.e. connected to positive terminal of the circuit. The output of regulated voltage -5V is taken out from the output pin 3 of the IC. C1and C2 acts as smoothing function of the input and output voltages. The power source can deliver upto 1 Amp. current. 

Assembling

The circuit can be assembled on any general purpose PCB. The IC7905 can be mounted on the PCB securely fitted with a proper heatsink with bolt and nuts. The heatsink is required to handle high power distribution in case it is used in heavy demand circuit design utility circuits. 

Conclusion

A versatile negative supply rail is obtained by using popular 3 terminal IC7905. It fulfills most of the power supplies required for lab and utility circuits.