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A capacitive power supply usually has a rectifier and filter to generate a direct current from the reduced alternating voltage. Such a supply comprises a capacitor, C1 whose reactance limits the current flowing through the rectifier bridge D1. A resistor, R1, connected in series with it protects against voltage spikes during switching operations.
A leading power factor signifies that the load is capacitive, as the load supplies reactive power, and therefore the reactive component is negative as reactive power is being supplied to the circuit. If θ is the phase angle between the current and voltage, then the power factor is equal to the cosine of the angle, cos θ {\displaystyle ...
Power supplies with capacitors that have reached the end of their life or suffer from manufacturing defects such as the capacitor plague will fail eventually. When either the capacitance decreases or the ESR increases, the regulator compensates by increasing the switching frequency, thereby subjecting the switching semiconductors to ever ...
The filtering requirements for such power supplies are much easier to meet owing to the high frequency of the ripple waveform. The ripple frequency in switch-mode power supplies is not related to the line frequency, but is instead a multiple of the frequency of the chopper circuit, which is usually in the range of 50 kHz to 1 MHz. [citation needed]
The formula for complex power (units: VA) in phasor form is: ... (relying on parasitic resistance and inductance in the supply) or a capacitor-inductor network.
Capacitors and inductors as used in electric circuits are not ideal components with only capacitance or inductance.However, they can be treated, to a very good degree of approximation, as being ideal capacitors and inductors in series with a resistance; this resistance is defined as the equivalent series resistance (ESR) [1].
An external power supply, AC adapter or power brick, is a power supply located in the load's AC power cord that plugs into a wall outlet; a wall wart is an external supply integrated with the outlet plug itself. These are popular in consumer electronics because of their safety; the hazardous 120 or 240 volt main current is transformed down to a ...
In electronics, a bleeder resistor, bleeder load, leakage resistor, capacitor discharge resistor or safety discharge resistor is a resistor connected in parallel with the output of a high-voltage power supply circuit for the purpose of discharging the electric charge stored in the power supply's filter capacitors when the equipment is turned off, for safety reasons.