A regulator is an electronic circuit that regulates the output voltage of a power supply that is still mixed with ripple (non-linear current) and is not yet stable (i.e. the voltage is relatively high beyond tolerance).
1. Regular Regulator
It is a regulator that still uses a "step down" transformer with a fairly large physical size. In normal step down transformers there are 2 types, namely: CT (3 phase) and Standard (2 phase).
Transformer (Trafo)
Excess:
- Capable of producing very large currents (depending on the transformer used), usually for high-power amplifiers.
- The circuit is quite simple.
Weakness:
- takes up quite a lot of space because it still uses a regular transformer
- The output produced is not necessarily stable, for example:
Power Regulator
Active components frequently used for regulators are:
- 78 (+) 05, 12 - etc.
- 79 (-) 09, 18 - etc.
- Tr. Mj, 2N - etc.
2. Switching Regulator
Power Switching Regulator
Switching Regulator Schematic
How Switching Works:
- The DC rectifier voltage is fed to pin 3, via T801 and via pin 2 via R7,
- Q1 conducts / On and IC starts to flow,
- In T801 there is induction (coil between F1 and F2) voltage goes to the base of Q1 and makes the base voltage of Q1 increase to reach a large increase,
- IC Q1 rises to a full point where there is no major change in current, this causes the induction on T801 to rise. then with the cessation of induction on T801, the base voltage of Q1 decreases (+2), this will cause IC Q1 to drop. If there is a change in IC Q1 then induction occurs on T801, but this time what happens is reverse induction, because of the reverse induction on T801, the base voltage of Q1 is given the best polarity so that Q1 base drops below the cut off point and Q1 cut off.
- If Q1 is cut off then the energy from T801 is released from GND via F1 and F3 then to the load.
- Switching frequency 12-14 Khz
- To eliminate interference (beat) on the CRT screen, pulses from the FBT are fed through D805.
How a STABILIZER (STABILIZER REGULATOR) Works
- When the line voltage increases, IC Q1 does so as well as the voltage in the load.
- If the voltage on the load increases, the base voltage of Q3 also increases, while the emitter voltage of Q3 remains stable because it is still maintained by the zener diode, therefore the IC of Q3 increases.
- As a result, Vc Q3 decreases and IC Q2 increases (VBE Q2 increases).
- Thus, the base voltage Q1 decreases to reduce IC Q1 and finally the load voltage decreases and vice versa.