Why is there a motor in the circuit。。。。。

The first floor describes the phenomenon more or less correctly, but the understanding of the essence of the problem is not deep and clear. The working principle of the motor is to use the magnetic effect of the electric current, and at the same time as the magnetic effect, the coil generates an induced electromotive force opposite to the applied voltage, which causes a fundamental change in the structure of the circuit, so that the circuit cannot be understood from the perspective of Ohm's law, so the phenomenon you mentioned appears.

When there is a motor, the circuit is not a pure resistance circuit, so Ohm's law cannot be used.

The electric motor uses electromagnetic induction and generates a back electromotive force when turning. So the current will decrease. However, the energy loss may be the same as that of a certain resistor.

The motor will do work externally, and the electrical energy will be less, and the current will be reduced.

The friend who asked this question is a junior high school student, right?

This problem is actually a problem of the speed of energy conversion. When there is an electric motor in the circuit, the speed of conversion from electrical energy to other energy is relatively fast, while only the resistance is, and the resistance is slower to convert the computer into thermal energy. (The so-called comparison is a comparison made with two existing objects in the circuit).

In fact, when there is only resistance, the current is also decreasing, but the speed is relatively slow, and the experimenter did not pay attention to it. If you look a little longer, you'll see that the current is decreasing.

You're talking about battery-powered circuits, right?

The electric motor consumes much more energy than the resistor.

The energy dissipated by the resistor can only be released in the form of heat.

But the energy consumed by the electric motor is the mechanical energy + thermal energy it converts.

So the energy consumed by the motor is much greater than the resistance.

If the appliance is not used, it will be short-circuited. Resistance is also considered an electrical appliance.

1.There is a problem with the electric motor in the circuit.

1.There is a problem with the motor in the circuit, pro! Hello, I am glad to answer your <> pro 1

The solution to the problem of having a motor in the circuit is as follows: 1. After the power is turned on, the motor cannot start, but there is a humming sound. Possible causes. (1) The power supply is not fully connected to a single-phase start; (2) Motor overload; (3) Stuck by dragging machinery; (4) The rotor circuit of the wound motor is open and disconnected; (5) The position of the internal head of the stator is wrong, or there is a broken wire or short circuit.

Solution: (1) Check the contacts of the power cord, motor lead-out wire, fuse and switch, find out the open circuit position, and eliminate it; (2) No-load or half-load start after unloading; (3) Check the dragged machinery and eliminate the fault; (4) Check the connection of each contactor of brushes, slip rings and starting resistors; (5) Re-determine the head and tail end of the three-phase and check whether the three-phase winding is broken and short-circuited. 2.

The motor is difficult to start, and the speed is low after the rated load is added. Possible causes. (1) The power supply voltage is low; (2) The original triangular connection was mistakenly connected into a star connection; (3) The cage end of the squirrel cage rotor is desoldered, loose or broken.

Solution: (1) Increase the voltage; (2) Check the nameplate wiring method and correct the stator winding wiring method. (3) Symptomatic treatment after examination.

3.After the motor is started, the heat exceeds the maximum allowable temperature rise standard of the motor or smokes. Hope mine can help you <>

Do you have any other questions?

The principle of motor circuit refers to how to use electrical principles to control and drive electric motors. This includes the operating principle of the motor, circuit composition, control mode and protection. The operation of the motor requires a three-phase or single-phase power supply, and the current and voltage are regulated by the starter, controller and protection device in the circuit to control the speed and torque of the motor.

The circuit of an electric motor usually consists of the following parts:

1.Power supply: A three-phase or single-phase power supply that provides electrical energy to an electric motor.

2.Starter: A device that starts an electric motor, usually a capacitor or relay.

3.Controller: A device that adjusts the speed and torque of an electric motor.

4.Protective device: Protects the motor from overload and short circuit.

When controlling the motor, the commonly used methods are governor and frequency converter, which can adjust the speed by adjusting the voltage and frequency of the motor. There are other components such as contactors, relays, insulation monitoring devices, etc., which are commonly used for motor control.

In short, the principle of motor circuit is a combination of electricity and electrical science, and how to control and drive the motor to ensure the stability and efficiency of the motor operation.

In addition, it should be noted that the motor needs different circuit configurations under different working conditions, such as starting, running, and stopping.

Starting circuit: When starting, the motor needs to start with high current, so the starting circuit usually adopts star connection or series capacitor to reduce the voltage and ensure the reliable start of the motor.

Running circuit: In the running state, the motor needs to maintain a certain voltage and frequency to maintain the speed, and the running circuit usually adopts the connection method of three-phase parallel connection or single-phase parallel connection.

Stop circuit: In the stop state, the motor needs to be disconnected from the power supply, and the stop circuit usually uses a contactor or relay to control the stacking.

In short, the principle of motor circuit is a very wide field, and the motor circuit is configured with different circuits according to the different working conditions of the motor, so the design and selection of the motor circuit are very important to ensure the safe operation of the motor under different working conditions.

In addition to the circuit components mentioned above to control the motor, there are some commonly used motor drivers that can also be used to drive the motor. These drives include DC drives, AC drives, and servo drives.

DC drive, which converts AC power into DC power and then drives DC motor.

AC drive, which drives an AC motor.

Servo drives, drive servo motors. Servo motors can precisely control speed and position, and are commonly used in precision control applications such as robotics and industrial automation equipment.

These motor drives can provide high efficiency, high precision, and high reliability motor control. However, it should be noted that these drives need to be operated and maintained in strict accordance with the instructions when in use.

The principle of motor circuit is a combination of knowledge of electricity and electrical engineering, understanding the working principle of the motor, and being familiar with various motor control and driving methods, which helps to design an efficient, safe and stable motor system.

The motor is composed of a stator, a rotor and a support end cover.

Motors, stepper motors, deceleration stepper motors, and open-loop controlled motors are driven by input periodic signals without the need for circuit boards. Closed-loop controlled motors require closed-loop control circuits. The servo requires a circuit board, which is actually used to convert the periodic signal into a pulse signal.

The difference between motors, servos and servo motors is the joint drive method.

Joint drive mode:

Universal: Motor.

Point, angle:

Servos. Line, line:

Mechanical transmission 1st generation: screw servo mechanism.

The first generation of gas-liquid compression: cylinder manipulator mechanism.

Mechanical transmission 2nd generation: screw electric cylinder mechanical arm mechanism.

Gas-liquid compression 2nd generation: hydraulic manipulator mechanism.

Inductance, capacitance, spark reduction,

Answer: The motor is made by using the principle of the force of the energized wire in the magnetic field, and the speed of its rotation is related to the size of the current, so the speed regulating handle can adjust the speed, that is, the current in the circuit is regulated by the speed regulating handle, so it is equivalent to a sliding rheostat.

Its function is: the magnitude of the resistance is changed by changing the length of the resistance wire connected in the circuit, and the magnitude of the current in the circuit is changed by changing the size of the resistance

An electric motor is a device that converts electrical energy into mechanical energy.

It uses an energized coil (that is, the stator winding) to generate a rotating magnetic field and acts on the rotor (such as a squirrel cage closed aluminum frame) to form a magnetoelectric dynamic rotational torque. The motor is divided into DC motor and AC motor according to the different power sources, and most of the motors in the power system are AC motors, which can be synchronous motors or asynchronous motors (the magnetic field speed of the stator of the motor is not synchronized with the rotation speed of the rotor). The motor is mainly composed of a stator and a rotor, and the direction of the energized wire in the magnetic field is related to the direction of the current and the direction of the magnetic inductance line (magnetic field direction).

The working principle of the motor is the effect of the magnetic field on the current force, which makes the motor rotate.

It is the mechanical energy that converts electrical energy into the rotation, motion, etc. of a motor.

5.How does an electric motor work? (DC motor).

Q: What electric motors do not conform to Ohm's law? Because there is an induced electric potential in the armature winding of the motor, it is not simply a resistor. If we look at the induced potential and impedance, then Ohm's law must also be true.

Doesn't the u, i, r of the motor have anything to do with it? In addition, there is an e (induced electric potential).

The current of the motor is the armature current of the motor = (u-e) ra, so the current of the motor is always smaller than that calculated by the even-ohm's law.

Do you know why Ohm's law can be used for purely resistive circuits? Why is a law not a theorem?

The answer is experimentation.

Experiments show that Ohm's law cannot be used for impure resistive circuits.

The current theory is unprovable.

There is an inductance in the coil that hinders the current, called inductive reactance, which is similar to the effect of resistance on the current.

We use DC motors to explain these problems, because AC motors also involve the problem of power factor. For beginners, it's not easy to understand.

1. When the motor is connected to the DC power supply, the voltage of the two power terminals of the motor is the voltage borne by the motor.

2. The resistor is connected in series in the power supply circuit of the motor, the voltage drop on the resistance is measured, and then the total voltage is subtracted from the voltage drop on the resistor, which is the input voltage of the motor.

3. The power of the motor p=U i=i motor input voltage, i = motor input voltage motor internal resistance, r = motor internal resistance. That u is the voltage subtracted from the resistor in (2), which is also the voltage u in (1), not the supply voltage u in (2).

4. Total voltage = 6 V [2 (ohms) + 2 (ohms)] 2 (ohms) = 3V (volts).

1.The voltage measured on both sides of the motor is not its real voltage, right??

The measured voltage is the instantaneous voltage at which it is currently operating.

2.Suppose a resistor is connected in series with a motor, and the voltage is measured at both ends of the resistor, and then the total voltage is subtracted from the measured voltage, is the real voltage of the motor?

Yes 3Is the input power of the motor calculated by UI? And does that u refer to the u in 2 minus the resistive voltage, rather than the measured u in 1?

Is there a difference between these two?

4.Suppose the total voltage is 6 V, a resistance is 2 ohms, and the motor resistance is 2 ohms, so is the voltage at both ends of the motor 3V?

Not necessarily, it depends on the load size of the motor. The heavier the load, the lower the voltage at both ends of the motor. In extreme cases, the motor stops or reverses, and the voltage at both ends of the motor may only be 3V or lower, or even negative voltage. At this time, the resistor has the effect of protecting the motor.

When the motor rotates, it generates a back EMF, which is equivalent to a generator. The higher the rotational speed, the greater the back EMF. When it is close to the mains voltage, the current of the motor is very small, and the voltage is close to the mains voltage. Basically reach the maximum speed.

1) is its true voltage.

2) It's not. Because the electric motor is an inductive load. You can't use algebraic sums to apply vector sums.

3) The input power of the motor should be 1 u

4) It's not. The voltage of the electric motor is much higher than that of 3v. The impedance of an electric motor is much greater than that of 2 ohms.

(And when measured, is the motor charged or not?) I don't know if the true voltage you are talking about is the voltage generated by the resistance of the motor coil itself. The so-called measured voltage is the self-inductance voltage of the motor inductance coil plus the voltage generated by the resistance of the motor coil itself.

To figure out how voltage is generated, these questions are simple addition and subtraction problems.

1) Right. 2) It's not.

3) It is used ui, but it is not the u (4) subtracted from the resistance voltage in 2 can not be determined, I don't know whether the motor rotates or not, if it does not rotate, it is 3V, and it is not 3V.