Series voltage stabilizing circuit with amplification link

Series voltage stabilizing circuit with amplification link

The circuit shown is a series voltage stabilizing circuit with an amplification link. Although the variation range of the load current is expanded, because Uo=UZ
- UE, the stability of the output voltage is worse than without the adjustment tube. On the other hand, the output voltage still cannot be adjusted continuously. The improved
method is to introduce an amplification link in the voltage stabilizing circuit. VTI in the picture is the adjustment tube. VT2 is the amplifier tube, and Ra is the collector load resistor of VT2 .
The function of the amplifier tube is to amplify the change in the output voltage of the voltage stabilizing circuit first, and then send it to the base of the adjustment tube. In this way, as long as there is
a slight change in the output voltage, it can cause a relatively large voltage drop in the adjustment tube. changes, thus improving the stability of the output voltage. The greater the amplification factor of the amplifier tube
, the better the stability of the output voltage. Ri, R2, and the code form a voltage divider, which is used to sample the output voltage
, so it is called a sampling resistor. where R2 is an adjustable resistor. The voltage regulator tube provides a reference voltage, and the sampled voltage taken from Rz is compared with the reference voltage and then
sent to the VT2 tube for amplification. The function of the resistor R is to ensure that VDZ has L suitable working voltages.