Classification and Application of Linear DC Regulated Power Supplies
I. Definition and Classification of DC Regulated Power Supply
DC regulated power supply is also known as DC voltage regulator. Most of its supply voltage is AC voltage, and the direct output voltage of the voltage regulator can remain stable when the voltage of the AC supply voltage or the output load resistance changes. The parameters of a voltage regulator are voltage stability, ripple factor and response speed. The former indicates the effect of changes in the input voltage on the output voltage. Ripple coefficient indicates that under rated operating conditions, the size of the AC component of the output voltage; the latter indicates that when the input voltage or load changes drastically, the time required for the voltage to return to the normal value. DC regulated power supply is divided into two categories of continuous conductive and switching. The former by the industrial frequency transformer to single-phase or three-phase AC voltage to the appropriate value, and then rectified, filtered, to obtain an unstable DC power supply, and then by the voltage regulator circuit to obtain a stable voltage (or current).
This power line is simple, small ripple, mutual interference is small, but the volume is large, more consumables, low efficiency (often less than 40% to 60%). The latter to change the adjustment element (or switch) on-off time ratio to regulate the output voltage, so as to achieve voltage regulation. This type of power supply power consumption is small, the efficiency can be up to 85% or so, but the disadvantage is that the ripple is large, mutual interference. Therefore, the rapid development since the 80s.
DC regulated power supply can be divided into from the working mode:
(1) controllable rectifier type. Adjust the output voltage by changing the conduction time of the thyristor.
(2) Chopper type. The input is unstable DC voltage, to change the on-off ratio of the switching circuit to get unidirectional pulsating DC, and then filtered to get a stable DC voltage.
(3) Converter type. Unstable DC voltage is first converted into high-frequency alternating current by the inverter, and then by the transformer, rectifier, filtering, from the new DC output voltage sampling, feedback control of the inverter frequency, to achieve the purpose of stable output DC voltage.
Second, the use of DC regulated power supply
AC regulated power supply is used in computer and its peripheral devices, medical electronic instruments, communication and broadcasting equipment, industrial electronic equipment, automatic production lines and other modern high-tech products of voltage regulation and protection.
DC regulated power supply is widely used in national defence, scientific research, colleges and universities, laboratories, industrial and mining enterprises, electrolysis, electroplating, charging equipment and other DC power supply.
(1)Can be used for various electronic equipment aging, such as PCB board aging, home appliances aging, all kinds of IT products aging, CCFL aging, lamp aging
(2)Applicable to the need for automatic timing power on and off, automatic recording cycle number of electronic components of the aging, testing
(3) Electrolytic capacitor pulse aging
(4) Resistors, relays, motors and other testing and aging
(5) The whole machine aging; electronic components performance testing, routine testing.
