The primary function of a bleeder resistor in a power supply is to provide a safe discharge path for the stored charge in the filter capacitors when the power is turned off. Additionally, it can also help improve voltage regulation. By drawing a small constant current through the power supply, the bleeder resistor can help stabilize the output voltage, especially under varying load conditions.

In power supply circuits, the two most common types of filters used are choke input filters and capacitor input filters. Choke input filters use an inductor (choke) as the primary filtering element, while capacitor input filters use a capacitor. Both types have distinct characteristics in terms of voltage regulation, ripple reduction, and efficiency.

In a regulated power supply, the output of the electrolytic filter capacitor, which smooths the rectified DC, is typically connected to the voltage regulator. The voltage regulator’s role is to maintain a stable output voltage regardless of variations in the input voltage or load conditions. This setup ensures that the regulated power supply provides a consistent and reliable DC output.

Static regulation refers to the ability of a power supply to maintain a constant output voltage despite long-term changes in the load resistance. It is a measure of how well the power supply can adapt to gradual variations in the load over time, ensuring that the output voltage remains stable.

A shunt regulator is used in applications that require a constant load on the unregulated voltage source. In a shunt regulator, the control element is connected in parallel with the load. It operates by shunting excess current away from the load to maintain a stable output voltage. This configuration ensures a constant load on the unregulated source, regardless of variations in the load.

The maximum output voltage available from a full-wave bridge rectifier circuit is approximately the same as that from a full-wave center-tap rectifier circuit for a given transformer. Both types of rectifiers effectively use both halves of the AC cycle, but the bridge rectifier does so without the need for a center-tapped transformer.

In a regulated power supply, four diodes connected in a bridge configuration form a bridge rectifier. This arrangement allows for full-wave rectification, efficiently converting alternating current (AC) from the transformer into direct current (DC). The bridge rectifier is a crucial component in many power supplies, providing a more consistent and higher voltage output compared to half-wave rectification.

In a half-wave rectifier with a capacitor input filter, the peak inverse voltage (PIV) across the diode can be significantly higher than the RMS voltage of the transformer secondary. This is because the capacitor charges up to the peak voltage of the transformer secondary, and the diode must withstand this voltage in reverse bias when the AC waveform goes negative. The PIV can reach approximately 2.8 times the RMS voltage in such a setup.

A switching voltage regulator operates by rapidly switching a control device (like a transistor) on and off. The duty cycle (the ratio of the on-time to the total cycle time) is adjusted in response to changes in the input voltage or load conditions. This switching action, combined with inductive and capacitive elements, allows the regulator to efficiently maintain a stable output voltage.

In designing a power supply, particularly one with a choke input filter, it is important to carefully select the first choke and the first capacitor to avoid resonance effects. If the inductance of the choke and the capacitance of the capacitor are not properly matched, they can form a resonant circuit, which may lead to an undesirable increase in ripple voltage. Proper selection and matching of these components are crucial to ensure stable operation and effective filtering

In a power supply, if the first choke and the first capacitor inadvertently form a series resonant circuit, it can lead to excessive rectifier peak current and abnormally high peak inverse voltages. This resonance can cause the voltage across the capacitor to rise significantly, potentially damaging the rectifier and other components. Careful selection and design are needed to prevent such resonance in the filter circuit.

In a full-wave center-tap rectifier, the peak inverse voltage (PIV) across each diode is twice the peak voltage of the transformer secondary, which is approximately 2.8 times the RMS voltage. This is because each diode in a full-wave center-tap rectifier conducts for half of the AC cycle and must withstand the full peak voltage in reverse bias during the other half of the cycle.

A full-wave rectifier with a choke input filter provides the best voltage regulation under similar load conditions. The choke input filter helps maintain a more constant output voltage across varying loads, and the full-wave rectification ensures that the entire AC waveform is utilized, leading to a more stable and efficient power supply.

For a three-terminal regulator, important characteristics include the output voltage and the maximum output current it can provide. The output voltage specifies the regulated voltage the device will maintain, while the maximum output current indicates the highest current the regulator can supply while maintaining the specified output voltage.

A diode connected across the input and output terminals of a voltage regulator in a power supply is typically used to protect the regulator from reverse voltages. This diode can prevent damage to the regulator if the polarity of the supply voltage is accidentally reversed or if a reverse voltage spike occurs. It acts as a safeguard, ensuring the longevity and reliability of the power supply.

Increasing the value of the output capacitor in a power supply improves its dynamic regulation. A larger output capacitor provides better filtering and can store more energy, which helps to maintain a stable output voltage during rapid changes in the load or input voltage, thereby enhancing the power supply’s dynamic response.

In a regulated power supply, fuses are components that can conduct both alternating current (AC) at the input before the transformer and direct current (DC) before the output. Fuses are safety devices designed to protect the power supply and connected equipment from overcurrent conditions by breaking the circuit if the current exceeds a certain threshold.

In a power supply, series chokes (inductors) are used to impede the flow of AC while allowing DC to pass through. Inductors resist changes in current, making them effective at blocking alternating current (AC) components in a power supply while allowing direct current (DC) to pass with minimal resistance. This property makes them useful in filtering out AC ripple from rectified DC in power supply circuits.

In a half-wave rectifier circuit, the ripple frequency is the same as the frequency of the AC supply. For a standard household AC supply of 60 Hz, the ripple frequency in a half-wave rectifier will also be 60 Hz. This is because the half-wave rectifier only uses one half-cycle (either positive or negative) of the AC waveform, leaving the frequency of the ripples in the output the same as the input AC frequency.

In a bridge rectifier circuit, both halves of the AC input waveform are used, resulting in a higher average output voltage compared to half-wave or full-wave center-tap rectifiers. The bridge rectifier is more efficient in converting AC to DC, as it utilizes the entire AC cycle, leading to a higher average DC output voltage for the same transformer secondary voltage

In power-supply circuits, silicon-diode rectifiers are crucial components that allow current to flow in one direction but block it in the opposite direction. They’re like one-way streets for electricity. However, to ensure they work properly and safely, there are two main “rules” or ratings we need to follow:

1. Peak Inverse Voltage (PIV): Imagine pushing against a door that only opens one way. If you push too hard on the wrong side, you might break the door. The PIV is like the maximum force you can push on the door (the diode) in the wrong direction (reverse) without breaking it. If the voltage trying to push through the diode in the reverse direction gets too high, higher than the PIV rating, the diode could get damaged.

2. Average Forward Current: Now, when you open the door the right way with just the right amount of force, it opens smoothly. This is like the diode allowing electricity to flow through it in the forward direction. The average forward current is like the maximum average strength you can use to open the door regularly without wearing out the hinges (the diode) over time. If the diode carries more current than it’s rated for, it can overheat and potentially fail.

In a choke input filter power supply, it is advisable to use capacitors rated at the peak transformer voltage as a safety margin. This is because, under certain conditions such as no-load and a failed (burned-out) bleeder resistor, the voltage across the filter capacitor can rise to the peak transformer voltage. Using capacitors rated for this higher voltage ensures they can withstand these potential conditions without failing.

Full-wave voltage doublers are designed to use both halves of the AC wave. Unlike half-wave doublers that only use one half-cycle of the AC input, full-wave doublers effectively utilize both the positive and negative half-cycles. This allows them to double the peak voltage of the AC input, leading to a higher output voltage compared to half-wave doublers.

A choke input filter in a power supply provides the best voltage regulation with a normal load. The inductance of the choke helps to maintain a more constant output voltage by smoothing out variations in the input voltage, especially under varying load conditions. This results in a more stable output compared to other types of filters.

Increasing the output capacitance in a power supply filter improves dynamic regulation, especially for applications like SSB (Single Sideband) or CW (Continuous Wave) transmitters. A larger capacitance provides better energy storage and smoother filtering, which helps maintain a stable output voltage under varying load conditions, such as those encountered in transmission.