# Tag Info

6

...the field coil wires are covered with a fine plastic film insulation, however this has perished in places. Could this be causing the issues, and if do what's the best fix please? The only fix is to rewind the field. You will need to look for detailed instructions, information about the materials and a supply source. You may find that it is more ...

4

You are looking for a servo motor with encoder feedback. The motor itself could be any type and position control done by, for example, a PID controller and feedback from the encoder. Many modern vehicles already have steering angle sensors. Figure 1. Some vehicles are fitted with steering-angle sensors. It may be possible to read these over CANbus. Image ...

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Looks like it may be a centrifugal switch. https://mastersamuraitech.com/module-7/switches-and-relays/centrifugal-switch-schematic-symbol/

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Ordinarily, it is not necessary to protect a series motor against no-load operation. The motor's own mechanical losses will be sufficient to prevent the motor from operating at a speed that would cause damage. If the driven machine requires protection from excessive speed, a centrifugal switch can be used shut the motor off when an above-normal speed is ...

3

Can you convert your comment into an answer? – Stefan I expect that the increase in resistance is due to the emerging eddy current losses as frequency rises and, the decrease in inductance is due to eddy currents forming parallel inductances hence they reduce the net inductance.

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You can use a belt drive or gears to make it turn slower. If that adds too much complexion for the application, you can use a diode instead of the resistor, so that the motor can draw more current in ramping up the speed. Resistor will have a higher voltage drop on higher currents. With a diode the current dependency is much smaller.

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Using Google translate, that product is meant as a development board for motor control in robotics applications. FPGA allows much quicker or tighter control loops that would be crucial in running something like a robotic joint. FPGA is also a better fit in a development board because it can be reconfigured at the logic level.

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So current is charge/time, and you need to transfer 35nC in whatever the switching time is. Now picking 1/10 the the period probably isn't good enough, because you want the interval during which the switching takes place to be short because this is the time when the current flowing through your device and voltage across the device are both large, hence ...

2

Soft starting is mostly used where direct motor starting is difficult for the power distribution system. It may be needed to minimize voltage fluctuations. You can not get good advice about that without stating the power level of the motor and the location. Pumps may or may not be furnished with motor starters depending on the power level, the supplier, the ...

2

I have slight experience with residential well-pumps, pool pumps, and pressure booster pumps. None of them use soft start. Those I have dealt with are in the 3HP and less range. Single phase. Service life is OK. I think the centrifugal switch on the motor or the motor capacitors would be the first thing to fail. Maybe motor bearings for ODP motors in dirty ...

2

First, use the motor nameplate data to find kva (apparent power). Subscript 3 below indicates 3 phase. $$S_3 = \frac{HP * 746}{power factor * efficiency}$$ But, in your case the nameplate gives rated current as 48A, so $$S_3 = 48A * 575 * \sqrt3 = 47.8kva$$ $$P_3 = S_3 * power factor = 47.8 * 0.80 = 38.24kW$$ So, $$Q_3 = \sqrt{S_3^2-P_3^2} = 28.7kvar$$...

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You must read the instructions for the specific overload relay you have. Some require that you set them at exactly the motor FLA, the allowable "pick-up point" is already built-into the design. Others have you adjust the values based upon the motor design type, especially if you are in North America where we have "Service Factor" for ...

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The similar meaning as "a pole" in AC induction or synchronous motor, NOT the same meaning as "a phase" in AC induction or synchronous motor. Each of the 2 below images has 4 phases (x, $\overline{x}$, y, $\overline{y}$ are all individual phases. A, A', B, B' are all individual phases)

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If the control in implemented properly, you should be able to run the motor at half the speed that would be possible with 24 volts. For the same load torque, the current would be the same as with 24 volts.

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Is my thought process correct? Am I right in my understanding of reactive power? You are essentially correct except for: (as they dissipate power when the inductor consumes it) Should be: "as they store energy when the inductor releases it and release energy when the inductor stores it." There are several reasons that motors don't come with ...

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All the information is there. The wiring colours to the motor suggest that this is a three phase motor, just to confuse me. However yellow is the start switch blue is the auxiliary winding and red is the main winding. Run capacitor at the top, start capacitor at the bottom. This gives the following circuit diagram. Switching the link positions reverses the ...

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You can use a series resistor to reduce the speed of a small DC motor by reducing the voltage, but the effectiveness of that will be very limited. You can probably reduce the speed to 20 percent of the normal speed. The speed will vary with load variation. If you want something less than a few revolutions per second, the speed must be reduced mechanically. ...

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can I buy a motor speed control and have it do the same things as a variac? No. What are the fundamental differences between the two? A Variac reduces the voltage without modifying the sinusoidal waveform. A Variac is a variable-ratio autotransformer. The AC motor controls that provide good motor performance are variable frequency drives (VFD). They ...

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Pulsed DC voltage from a single phase bridge rectifier will mean that the current in the feild and hence the armature will be pulsing to some extent .The total inductance would have to be infinite to make the current waveform pure DC.The pulsing current will cause more motor losses than pure DC like a battery.But the losses are lower than a straight 230 VAC ...

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