Voltage Regulation Principle of Operation of Series Regulated Power Supplies
Assuming that the output voltage UO is reduced due to some reason, that is, the emitter voltage (UT1) E of T1 is reduced, due to UD1 remains unchanged, thus causing the T1 emitter junction voltage (UT1) BE to rise, causing the T1 base current (IT1) B to rise, which causes the T1 emitter current (IT1) E to be amplified by a factor of β to rise, as can be seen by the transistor's loading characteristics, which is when the T1 conduction is more Sufficiently tube voltage drop (UT1) CE will be rapidly reduced, the input voltage UI more added to the load, UO get back up quickly. This adjustment process can be expressed using the following variation relationship diagram:
UO↓→(UT1)E↓→UD1 constant→(UT1)BE↑→(IT1)B↑→(IT1)E↑→(UT1)CE↓→UO↑
When the output voltage rises, the whole analysis process is opposite to the change of the above process, we will not repeat here, but simply expressed by the following change relationship diagram:
UO↑→(UT1)E↑→UD1 constant→(UT1)BE↓→(IT1)B↓→(IT1)E↓→(UT1)CE↑→UO↓
Here we only analyze the output voltage UO reduced voltage regulation principle of operation, in fact, the input voltage UI reduced in other cases such as voltage regulation principle of operation are similar to this, * ultimately are reacting to the output voltage UO reduced, so the principle of operation is roughly the same.
From the working principle of the circuit can be seen, the key to voltage stabilization of two points: one is the regulator D1 regulator value UD1 to remain stable; the second is to adjust the tube T1 to work in the amplification area and the operating characteristics should be good.
Precautions for the use of DC regulated power supply
1. In order to prevent magnetic interference, the regulator and the use of equipment placed between the distance should not be less than 2 meters. All kinds of magnetic records, discs, cards, etc. should be kept away from the machine 2 meters away, in order to prevent accidental magnetization.
2. Voltage regulators generally include input terminals (A, B, C), output terminals (a, b, c, n), shielding, core shell grounding terminals. These terminals have been correctly connected in the voltage regulator system.
3. If the load imbalance exceeds 20%, connect a resistive load in parallel with the lightly loaded phase to balance it. Similarly, if the unbalance of the line voltage at the input is more than 10%, it will also affect the voltage regulator's performance. In this case, a single-phase regulator should be set up at the input to make the line voltage at the input basically balanced. Input voltage and load two balanced degree does not exceed the above range, the output line voltage unbalance ≤ 5%.
4. When the load equipment has a short circuit, the user needs to shut down the machine to check and eliminate the short-circuit fault and then turn on the machine again. 5. When working continuously for a long time, the machine has a certain temperature rise, the indication value will be slightly lower than the actual voltage value. 6. Should be placed in a well-ventilated location, if the ventilation conditions are poor, please install a ventilation fan in the room.
