Classification and Applications of Linear DC Regulated Power Supplies
1, Definition and classification of DC stabilized power supply
DC stabilized power supply, also known as DC stabilizer. Its power supply voltage is mostly AC voltage, and when the voltage of the AC power supply voltage or the output load resistance changes, the direct output voltage of the voltage regulator can remain stable. The parameters of a voltage regulator include voltage stability, ripple factor, and response speed. The former represents the impact of changes in input voltage on output voltage. Ripple coefficient represents the magnitude of the AC component in the output voltage under rated operating conditions; The latter represents the time required for the voltage to return to normal when there is a sudden change in input voltage or load. DC stabilized power supplies are divided into two types: continuous conductive and switch mode. The former uses a power frequency transformer to convert single-phase or three-phase AC voltage to an appropriate value, and then rectifies and filters it to obtain an unstable DC power supply, which is then stabilized by a voltage regulator circuit to obtain a stable voltage (or current).
This type of power supply circuit is simple, with low ripple and minimal mutual interference, but it has a large volume, consumes a lot of materials, and has low efficiency (often below 40% to 60%). The latter adjusts the output voltage by changing the on-off time ratio of the adjusting component (or switch) to achieve voltage stabilization. This type of power supply has low power consumption and an efficiency of about 85%, but the disadvantages are large ripple and mutual interference. So, it has developed rapidly since the 1980s.
DC stabilized power supply can be divided into:
(1) Controllable rectification type. Adjust the output voltage by changing the conduction time of the thyristor.
(2) Chopping type. The input is an unstable DC voltage, which is obtained by changing the on-off ratio of the switch circuit to obtain unidirectional pulsating DC, and then filtered to obtain a stable DC voltage.
(3) Transformer type. Unstable DC voltage is first converted into high-frequency AC power by an inverter, and then transformed, rectified, and filtered. The resulting new DC output voltage is sampled and feedback controlled to regulate the inverter's operating frequency, achieving the goal of stable output DC voltage.
2, The purpose of DC stabilized power supply
AC stabilized power supply is used for stabilizing and protecting modern high-tech products such as computers and their peripheral devices, medical electronic instruments, communication and broadcasting equipment, industrial electronic equipment, automatic production lines, etc.
DC stabilized power supply is widely used for DC power supply in national defense, scientific research, universities, laboratories, industrial and mining enterprises, electrolysis, electroplating, charging equipment, etc.
(1) Can be used for various electronic device aging, such as PCB board aging, home appliance aging, various IT product aging, CCFL aging, lamp tube aging
(2) Suitable for aging and testing of electronic components that require automatic timed power on/off and automatic cycle counting
(3) Electrolytic capacitor pulse aging
(4) Experienced in testing resistors, relays, motors, etc
(5) The whole machine is experienced; Performance testing and routine testing of electronic components.
