Power supply is very important in electronics and most electronic circuits need stable DC voltage.
However, AC voltage comes from mains and therefore the conversion is required.
This Transistor Based 5V Linear Power Supply Circuit gives regulated 5 volts DC.
It uses simple components, gives high current and is useful for labs and projects.
Circuit Working:
Parts List:
| Components | Value | Quantity |
|---|---|---|
| Resistors | 150Ω, 220Ω | 1 each |
| 100Ω | 2 | |
| Preset 100Ω | 1 | |
| Capacitor | Electrolytic 4700uF 25V | 1 |
| Semiconductors | Transistor TIP3055 | 1 |
| Transistor BD139 | 1 | |
| Bridge Diodes 1N4004 | 4 | |
| Diodes 1N4148 | 4 | |
| Transformer 6.3V AC 1A to 2A | 1 | |
| Heat Sink For TIP3055 | 1 |
At start the circuit uses a step down transformer and then AC mains goes into the transformer.
Then voltage is reduced to 6.3V AC.
After that the bridge rectifier changes AC into pulsating DC.
Then capacitor C1 removes the ripple and so the DC becomes smooth.
Now transistor Q2 controls the voltage reference.
At the same time the diodes D5 and D6 make reference voltage and then VR1 is used to adjust the output voltage.
After this the transistor Q1 TIP3055 works as series pass transistor which carries high current load, so the voltage stays stable.
Finally, diode D7 protects the output from reverse voltage and as a result a regulated 5V DC is obtained.
How to Build:
To build a Transistor Based 5V Linear Power Supply Circuit follow the below connection steps:
- First, start the circuit by collecting all the parts as shown in circuit diagram.
- Then start with transformer primary end is connected to 110V AC mains.
- Secondary end is connected to bridge rectifier input D1-D4.
- Capacitor C1 positive pin connected to rectifier positive.
- Negative pin connected to ground.
- Transistor Q1 TIP3055 base is connected between to R2 and collector of Q2.
- Collector connected to unregulated DC.
- Emitter gives regulated 5V output.
- Transistor Q2 BD139 base pin is connected to VR1 center pin.
- Collector connected to R1 and base of transistor Q1.
- Emitter connected to anode of diode D5.
- Diodes D5 and D6 are connected in series for reference voltage.
- At last, Diode D7, resistor R3, VR1 and resistor R4 are connected in series from 5V positive supply to GND.
Conclusion:
This Transistor Based 5V Linear Power Supply Circuit is simple and useful project
Also, it is easy to build as it gives stable output.
Transistor TIP3055 handles high current well and with proper heat sink it works reliably.
Therefore, this circuit is very useful for electronics projects and is good for beginners.