Simple Hum Free Regulator Power Supply Circuit

This circuit builds a clean and steady power supply using a common transistor called a 2N3055.

It gets rid of any annoying background noises ‘hum’ that can sometimes come from power supplies.

What is a Hum Free Regulator Power Supply:

A Hum Free Regulator Power Supply circuit is an electronic circuit designed to provide a stable and regulated output voltage to electronic devices while minimizing or eliminating the unwanted electrical hum or noise commonly associated with power supplies.

This type of circuit typically incorporates voltage regulation components and filtering techniques to ensure a clean and steady power output reducing interference in audio and sensitive electronic applications.

Circuit Operation:

Parts List:

The 25V 5A transformer provides an AC voltage output.

The AC voltage is rectified using a 6A4 diode resulting in a pulsating DC voltage.

The 220uF filter capacitor smoothens the pulsating DC producing a relatively stable DC voltage of around 30V.

The 30V DC voltage from the filter capacitor is applied to the collector of the 2N3055 transistor.

The base of the 2N3055 transistor is connected to the 30V line through a 1k resistor.

This resistor provides bias to the transistor.

A 10uF capacitor is connected between the base of the 2N3055 transistor and the ground line.

This capacitor is responsible for creating a pure and constant DC voltage at the base of the 2N3055 transistor.

The emitter of the 2N3055 transistor is the output of the regulator and it produces a regulated and hum-free DC voltage.

Operation Explanation:

• The 1k resistor biases the 2N3055 transistor allowing it to regulate the output voltage.
• The 10uF capacitor connected between the base and ground serves as a low pass filter filtering out any high frequency noise or AC ripple present on the 30V line.
• This capacitor creates a constant DC voltage at the base of the 2N3055 transistor ensuring a stable and hum free output.
• The 2N3055 transistor, configured as an emitter follower, provides a low impedance output that closely follows the voltage at its base.
• This helps in maintaining a stable output voltage.
• The regulated and hum free DC output from the emitter of the 2N3055 transistor can be used to power audio amplifier circuits ensuring that the audio output is clean and free from humming noise.

Advantages of the Circuit:

• The 10uF capacitor at the base of the 2N3055 transistor filters out AC ripple and noise providing a clean and hum free output.
• The 2N3055 transistor acting as an emitter follower, regulates the output voltage to ensure stability.
• The simple hum free regulator power supply circuit is designed to provide a stable and clean power supply, making it suitable for audio amplifier circuits where a hum free power source is crucial for high quality audio output.

Safety:

• Remember to follow proper safety precautions and use the correct ratings for components based on your specific requirements.

Formulas:

You must make sure that voltage regulation, filtering and thermal management are done correctly while designing a circuit for a hum free regulator power supply.

Below mentioned are the general formulas for the same:

Base Resistor:

To adjust the 2N3055s base current, perform the following calculation:

R = V_diode​−V_BE​​ / I_B​

where,

• The diode voltage 15V for a 15V output, is denoted as Vdiode.
• The 2N3055s base emitter voltage roughly 2V is represented as VBE.
• The intended base current IB is usually around one tenth of the output current.

How is the Circuit Build:

Building the hum free regulator power supply circuit involve steps mentioned:

Circuit Assembly:

Input Stage:

• Connect the 25V, 5A transformer to the breadboard.
• Connect the secondary side of the transformer to the 6A4 rectifier diode to rectify the AC voltage.
• Connect the output of the diode to the positive supply of the breadboard.
• Connect the negative side of the diode to the negative supply of the breadboard.
• Connect the positive supply to the positive leg of the 220uF capacitor.
• Connect the negative leg of the capacitor to the negative supply.

Regulator Stage:

• Connect the positive leg of the 220uF capacitor to the collector of the 2N3055 transistor.
• Connect the emitter of the 2N3055 transistor to the ground supply.
• Connect the base of the 2N3055 transistor to the positive supply through a 1k resistor.
• Connect a 10uF capacitor between the base of the 2N3055 transistor and the ground supply.
• Double check all connections for correctness and secureness.

Testing:

• Power up the circuit and measure the output voltage across the emitter of the 2N3055 transistor and the ground supply using a multimeter.
• Adjust the input voltage if needed, and observe the stability of the output voltage.
• Measure the voltage across the 10uF capacitor to ensure a stable and constant DC voltage at the base of the 2N3055 transistor.

Important Considerations:

• Double check the transistor pin configurations and ensure they are connected correctly.
• Pay attention to the polarity of capacitors and diodes.
• Ensure that soldered connections are secure and free from short circuits.
• Start with a lower input voltage when testing the circuit to avoid damage.

Conclusion

Remember that this guide provides a general overview, and actual assembly may vary based on specific component datasheets or modifications.

If you are unsure about any part of the circuit or its assembly seek advice from experienced individuals or consult relevant resources.

Always prioritize safety and handle electronic components with care.

References:

Remote Control Hum Less Fan Controller Unit