![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
How to use DC power supply to realize input AC 220 V and output DC 110 V
Use a 220 V to 110 V transformer and add a silicon bridge
In three-phase symmetrical circuit, the voltage of power line is 380V, and the three-phase load r = 100
(1) The line current and the total power consumed by the load when the load is star connected
(2) the line current and the total power consumed by the load when the load is star connected, and the relationship between the active power of the two different connection modes is compared
Y type connection: load phase voltage is 220 V, phase current = line current = 220 / 100 = 2.2A. Three phase total power = 3x220 x2.2 = 1452 W. delta type connection: load phase voltage = line voltage = 380 V, phase current = 380 / 100 = 3.8 A. line current = 1.732x3.8 = 6.58 a, three-phase total power = 1.732x380x6.58 = 4330 W
Symmetrical three-phase AC circuit, 380V power line voltage, r = 16 Ω, XL = 12 Ω in each phase load, Y connection, phase voltage, phase current, line current and three-phase voltage
Z = (R * r + X * x) ^ 0.5 = 20 Ω Y connection: phase voltage U = 380 / root 3 = 220 V phase current I = u / z = 220 / 20 = 11 a line current = phase current = 11 a three-phase apparent power (capacity) s = root 3 * line voltage * line current = root 3 * 380 * 11 = 7240 VA three-phase has
5. Symmetrical three-phase AC circuit, 380V power line voltage, r = 16 Ω, XL = 12 Ω in each phase load, Y connection, phase voltage, phase current, line current and three-phase voltage
When the three-phase asynchronous motor is star connected, the line voltage is 3 times of the phase voltage, and the line current is the same as the phase current
RELATED INFORMATIONS
- 1. It is known that the complex impedance of each phase of the star connected load is Z = 12 + j16 Ω. When it is connected to a symmetrical three-phase power supply, the line voltage is 380V, and the line current is calculated If the three-phase load is changed to triangle connection, what is the line current?
- 2. If the line voltage of the power supply is 380V and the load impedance is 110 Ω, the line current and phase current of the circuit can be calculated
- 3. The voltage of a certain section of circuit is 120V, and the current flowing is - 2.5A. Do you want to know whether this section of circuit generates power or consumes power? What is the power? I The voltage of a certain section of circuit is 120V, and the current flowing is - 2.5A. Do you want to know whether this section of circuit generates power or consumes power? What is the power? I need it urgently
- 4. When Xiaoliang did the experiment of measuring "rated power of small light bulb", the equipment used included power supply with voltage of 6V, small light bulb with rated voltage of 2.5V (rated power of small light bulb is less than 1W), sliding rheostat (50 Ω 1a), and ammeter, switch and wire meeting the experimental requirements. As shown in figure (a), Xiaoliang did not connect the complete circuit
- 5. In the experiment of measuring the electric power of the small bulb, when the sliding rheostat is adjusted so that the voltage at both ends of the small bulb is higher than 1 / 5 of the rated voltage, the actual power of the small bulb is less than the rated power A. 6 / 5 times B.5 / 6 times C. 36 / 25 times d.4/50 times
- 6. Assuming that there are two bulbs in series (or in parallel), one is brighter than the other, then their actual electric power, rated power, actual voltage, rated voltage What is the relationship between actual current, rated current, actual power at the same time and rated power Please give the best explanation of the pushing process
- 7. How many hours can two 220 V, 40 W lamps work with one degree of electricity? How many hours can two "220 V, 40 W" lamps work with one degree of electricity? I can't get the formula right now
- 8. When the heater is not connected, the voltage is 210v. When the heater is connected, the voltage drops to 200V? In winter, after Li Ming plugged in the electric heater, he found that the light in the room was dim. He used a voltmeter to measure the power supply voltage. The result showed that the voltage was 210v when the heater was not connected. The voltage dropped to 200V when the heater was connected. The electric heater he used was marked with "220V, 1000W". From this, we can know the resistance of the power supply circuit__________ Ω, the actual power of the electric heater is____________ W. It's the resistance of the power supply circuit, not the resistance of the heater. 2.54 Ω, 826.4 w
- 9. The voltage at the circuit end measured by Voltmeter is zero, which means that () 1 external circuit is open circuit, 2 external circuit is short circuit, 3 current on external circuit is relatively small, 4 resistance in circuit is zero
- 10. The internal resistance of the voltmeter is very large. The ordinary small bulb is equivalent to a wire. Why is it not short circuited when the voltmeter measures the voltage of the small bulb?
- 11. An inductive coil is connected to a DC source of u = 120V, I = 20A. If it is connected to an AC source of F = 50 Hz, u = 220 V, I = 28.2a. Calculate the coil resistance and inductance
- 12. When an inductive coil is connected to the U = 220 V DC power supply, the current is I = 20 A; when it is connected to the F = 50 Hz, u = 220 V AC power supply, the current is I = 20 a
- 13. When a small light bulb works normally, the current is 0.5A and the resistance is 5 Ω. Now connect it to the circuit with voltage of 6V to make the small light bulb work normally, Should_____ Connect a resistance value of__________ Ohm resistance
- 14. A "6V, 0.5A" small bulb connected in series with a 24 ohm resistor is connected to a power supply, which can make the small bulb work normally. What is the power supply voltage? (with the knowledge solution of elementary 2)
- 15. How much resistance should a 36V, 60W arc lamp be connected in series in order to make it shine normally in the circuit with 110V supply voltage
- 16. The electromotive force of the power supply is e, the internal resistance is r, and the power supply supplies power to the variable resistance R. is the following statement about the terminal voltage correct? Why Because u = IR, when R increases, does the terminal voltage also increase
- 17. Ohm's law of the whole circuit points out that the current in the circuit is determined by the internal resistance of the power supply and the load resistance A power B voltage C resistance D electromotive force,
- 18. The same voltage power supply in parallel, in each power supply in series with a very small resistor can balance the current, what is the principle? Several power supplies of the same voltage are connected in parallel to provide large current. A small resistor in series on each power supply can balance the current. What is the principle? Now I also want to prevent one of the power supplies from breaking down and affecting other power supplies. Therefore, a diode is connected to each power supply, and the diode also has a certain resistance. Can it not only prevent the current from flowing back, but also balance the current? Can diode be connected in series instead of resistor? I know that the purpose is to prevent the current from flowing back, but what is the principle to facilitate my future use,
- 19. The equivalent resistance of the two terminal network is 10 ohm, the open circuit voltage is 40 V, and the maximum power consumed by the load is?
- 20. When the power supply voltage is fixed, the load with large resistance is a large load? Isn't it true that the size of the load is only related to the current? I remember the book said that the load with large current is called large load, so in the series circuit, the current is equal everywhere, and there will be different loads?