Is the adjustment range of the regulated power the smallest it can be?
The technical indicators of a regulated power supply can be divided into two categories: one is characteristic indicators, such as output voltage, output current and voltage adjustment range; the other is quality indicators, which reflect the advantages and disadvantages of a regulated power supply, including stability, Equivalent internal resistance (output resistance), ripple voltage and temperature coefficient, etc.
1. Characteristics of regulated power supply
(1)Maximum output current
It depends on the maximum allowable operating current of the main regulating tube, the capacity of the transformer, the maximum rectifier current of the diode, etc.
(2)Output voltage and voltage adjustment range
This can be determined according to the requirements of the object used. For equipment that requires a stable power supply, the adjustment range of the regulated power supply is best to be smaller, and the voltage value will not change once it is adjusted. For power supplies with adjustable output voltage, the output range is mostly adjusted from zero volts, and the voltage adjustment range is usually required to be wider and continuously adjustable.
(3)Protection characteristics
In a DC regulated power supply, when the load current is overloaded or short-circuited, the regulating tube will be damaged. Therefore, a fast-responding overcurrent protection circuit must be used. In addition, when the regulated current fails, the output voltage will be too high, which will cause harm to the load. Therefore, an overvoltage protection circuit is also required.
(4)Efficiency
The regulated power supply is a transducer, so there is also the issue of energy conversion efficiency. Improving efficiency is mainly to reduce the power consumption of the adjustment tube.
Main test methods for DC regulated power supply
1) It should be measured within the time interval of 1.5 seconds to 11.5 seconds after the load adjustment is completed.
2) The source voltage is measured at 198 volts, 220 volts and 242 volts respectively.
3) Stabilized power supply measurement method:
4) Steady current power supply time measurement method
5) When the load effect and the measurement of period and random deviation affect each other, they should be measured separately.
6) The measurement of load effect is the measurement of the change in voltage or current stable output caused only by changes in load.
7) The measurement of periodic and random excursions is the measurement of the irregular fluctuations (formerly called ripple and noise) in the stable output of voltage or current. The measurement frequency range is: 10Hz~10MHz. A single grounding point must be used during measurement to avoid measurement errors.
