Simple 9V to 300V Converter Circuit using a Single Transistor

This innovative 9V to 300V converter circuit can be used to transform a modest 9V DC output from a standard battery into a potent 300V DC supply.

What is a 9V to 300V Converter:

A 9V to 300V converter is a type of electronic circuit designed to convert a low voltage input of 9V to a higher output voltage of 300V.

This conversion is achieved through various electronic components, and circuit configurations and it falls under the broader category of DC-to-DC converters.

Circuit Working:

Parts List:

Lets go through the working of 9V to 300V converter circuit using a single transistor mentioned below:

T1 is a crucial component that transforms the initial 9-0-9V input into a higher voltage of around 250V.

This transformation occurs through the primary winding of T1.

The inductance L for the Hartley oscillator is provided by the primary winding of T1.

The Hartley oscillator is a type of LC inductor capacitor oscillator that generates an AC signal.

The secondary winding of T1 further boosts the voltage.

In this case, the 9V supply is elevated to a peak of approximately 350V

Following the voltage boost, the signal undergoes half wave rectification using diode D1.

This means that only one half of the AC waveform is allowed to pass through resulting in a unidirectional flow.

The rectified waveform charges capacitor C4.

Capacitors store electrical energy, and in this context C4 helps smooth out the rectified waveform, reducing fluctuations and creating a more stable DC output.

Under the influence of a load drawing several milliamperes the output voltage stabilizes at approximately 300 volts.

This stable output is achieved even when subjected to a sustained load.

The cautionary note about capacitor C4 is essential.

Since C4 is not continually loaded, it has the potential to store electrical charge and discharge it upon contact posing a risk of a severe but nonlethal shock particularly for those unfamiliar with the circuit.

The circuit transforms a 9V input into a higher DC voltage using a combination of a transformer, Hartley oscillator, rectification, and smoothing through a capacitor.

The warning underscores the importance of handling the circuit with care, emphasizing the potential shock hazard associated with the behavior of capacitor C4.

Formulas and Calculations:

You will be building a simple high voltage switch mode power supply that will enable you to develop a DC DC converter that uses a single transistor to step up a 9V input to about 300V.

Below are the relevant formulas to achieve this with the components to create a circuit you require:

Calculating Oscillator Frequency:

The values of the resistor and capacitor in the base circuit affect the oscillators frequency.

Using the 2N2222, you might apply the approximate formula as follows for a simple design:

f = 1​ / R * C * 1.1

where,

• C is the oscillator circuits total capacitance 0.01µF and
• R is the resistance 100k.

The frequency of a basic oscillator with a 0.01µF capacitor and a 100k resistor would be:

f = 1​ / 100k * 0.01µF * 1.1 = 90 kHz

Stepping increasing voltages may be demonstrated educationally using this simple setup.

More complex designs with feedback control and other parts would be needed for real applications in order to ensure steady and dependable functioning.

How to Build:

Building the 9V to 300V converter circuit using a Hartley oscillator involves several steps.

Transformer T1

• Connect the primary winding of T1 to the 9-0-9 volts source.
• The secondary winding produces a higher voltage.

Inductor L

• Utilize the primary winding of T1 as the inductor L for the circuit.
• Connect it to the circuit.

Oscillator Circuit

• Assemble the oscillator circuit using resistors, capacitors, and a transistor.
• The specific values and type of transistor depend on the design.
• Refer to the circuit diagram for proper connections.

Transformer T1 Secondary

• Connect the secondary winding of T1 to the oscillator circuit.
• This boosts the voltage.

Diode D1

• Connect diode D1 to rectify the AC signal produced by the oscillator circuit.
• Ensure it allows only one half of the waveform to pass through.

Capacitor C4

• Connect capacitor C4 to smooth the rectified waveform.
• This capacitor helps maintain a more stable DC output.

Load

• Connect the load resistor or other components to the output of the circuit.
• This simulates the actual application of the DC to DC converter.

Power Source

• Connect the 9V battery to the circuit to power the entire setup.

Testing

• Power on the circuit and monitor the output voltage.
• Adjust component values as needed to achieve the desired output.

Safety Considerations

• Due to the potential shock hazard associated with capacitor C4 take necessary precautions.
• Consider using discharge resistors or safety mechanisms to minimize the risk.

Conclusion:

This guide provides a general outline for constructing simple 9V to 300V converter circuit using a single transistor.

Refer to the specific datasheets for components and adjust the circuit based on your requirements and available components.

Additionally, adhere to safety guidelines and exercise caution especially concerning the warning mentioned about capacitor C4.

References:

DC/DC BOOK OF KNOWLEDGE