Inductors: making high voltage from low voltage

Summary

This video explores the fascinating world of inductors, focusing on their application in DC to DC converters, particularly in generating high negative voltages from low positive ones. The host delves into the theory and practical experiments, explaining how inductors store energy in a magnetic field and resist changes in current. A step-by-step demonstration shows how an inductor can boost voltage, using a simple circuit with a switch, resistor, and capacitor. The video also highlights the impact of pulse frequency on output voltage, culminating in a high-voltage output from a low-input voltage, showcasing the power of electronic components in circuit design.

Takeaways

• 🔌 Inductors are used in DC to DC converters to step up or convert low positive voltage to high negative voltage.
• 🧲 Inductors store energy in a magnetic field and release it when needed, similar to how capacitors store energy in an electric field.
• 📏 The two key parameters of an inductor are its inductance (measured in Henry) and the maximum current it can withstand (measured in Amperes).
• 🔍 An LCR meter is used to measure the inductance value of inductors, which can range from microhenries to millihenries.
• 🪵 The core material of an inductor, such as ferrite or iron, significantly increases its inductance compared to a simple wire winding.
• 🔗 Inductors resist changes in current; they act as an open circuit when current starts to flow and as a short circuit when the current is steady.
• ⚡ Boost regulators utilize the inductor's resistance to current change to momentarily create a voltage higher than the source voltage.
• 🔄 A diode and capacitor are used in conjunction with an inductor to capture and maintain the high voltage generated.
• 🤖 Electronic switches can replace manual button pressing in circuits, allowing for faster and more precise control of voltage boosting.
• 🎥 The video demonstrates practical experiments showing how inductors can be used to generate voltages much higher than the input, showcasing the power of electronic components.

Q & A

What is the primary function of an inductor in electronics?

An inductor's primary function is to store energy in the form of a magnetic field and release it when needed in the circuit.

What are the two most important parameters to consider when using inductors?

The two most important parameters are inductance, measured in Henry and symbolized by L, and the maximum current the inductor can withstand, symbolized by I and measured in amperes.

How does the presence of a core made of ferrite or iron affect the inductance of an inductor?

The presence of a core made of ferrite or iron greatly increases the inductance of an inductor because these materials can get magnetized, helping the inductor store more energy in the form of a magnetic field.

What is the difference between how a capacitor and an inductor store energy?

A capacitor stores energy in the form of an electric field, while an inductor stores energy in the form of a magnetic field.

How does an inductor resist changes in current?

An inductor resists changes in current by trying to maintain a constant current flow through it. When current flow is initiated or stopped, the inductor resists this change, which can be used to create a voltage boost.

What is the role of a diode in a voltage booster circuit involving an inductor?

In a voltage booster circuit, a diode allows the high voltage generated by the inductor to charge a capacitor but prevents the capacitor from discharging through the resistor, thus saving the high voltage.

How can an inductor be used to create a voltage higher than the source voltage?

An inductor can be used to create a higher voltage than the source by resisting the change in current when a switch is opened, forcing the current to flow through a resistor, which results in a higher voltage across the resistor according to Ohm's law.

What is the purpose of using an electronic switch instead of a manual switch in a DC to DC converter circuit?

An electronic switch can toggle at a much higher frequency than a manual switch, allowing for more rapid and precise control over the charging and discharging of the inductor, thus enabling more efficient voltage conversion.

How does the frequency of pulses impact the output voltage in a DC to DC converter circuit?

The frequency of pulses can greatly impact the output voltage by affecting how often the inductor charges and discharges. Higher frequencies can lead to higher output voltages, as seen in the script where an 80-volt output was achieved from a 0.5-volt input at a pulse frequency of 5 kHz.

What is the significance of using a PNP type or P Channel transistor in a DC to DC converter circuit?

In a DC to DC converter circuit, using a PNP type or P Channel transistor is beneficial when the switch is on the high side of the power supply. This configuration allows for effective control of the circuit's power flow and switching.