What is the working principle of an adjustable DC regulated power supply?
Rectifier and filter circuit works, characteristics and calculation of the main parameters.
1 silicon voltage regulator diode regulator circuit
1 Zener diode characteristics
The use of silicon diode reverse breakdown characteristics, can produce a zener diode. The general diode is not allowed to work in the reverse breakdown area, because the reverse current IR is large, the breakdown power consumption P = IR ?? UBR is very large, beyond the maximum allowable diode power loss, the diode Will be burned. Zener diode junction area of the larger, allowing greater power consumption, as long as the breakdown power consumption does not exceed the allowable value, the Zener diode will not burn. For example, there is a Zener diode power consumption PZ = 500mW, reverse breakdown voltage UBR = UZ = 10V, then the maximum reverse current
AC power through the diode rectifier filter, after large, medium power transistor, large and medium power transistor through the resistance conduction output power supply. Some designs are connected in series with a resistor to supply voltage to the Zener diode, giving a stable voltage difference between the two poles of the diode, some of which are designed after the transistor output. This stable voltage is called the reference voltage.
And then use a triode or manifold as a comparator, (+ output) one end of the reference voltage, the other end (b) a string of a current limiting resistor connected adjustable adjustable intermediate part of the adjustable resistance of the other two feet connected to the output voltage of the two poles The There is a pole connected, the power transistor triode, control the adjustment of the transistor conduction. Adjust the adjustable resistor to adjust the voltage.
Simply put, the principle is the output voltage through the comparison tube (manifold) with the reference voltage comparison, to control the large and medium power transistor conduction current, voltage, to achieve the purpose of regulation. Adjust the comparison voltage of the comparative tube (manifold) to adjust the output voltage.
Contempt ... ... sorry, for a long time do not touch, that large, medium-power transistor should be called what to forget ~ ~ ~
