Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rpm]

Revolutions Per Minute, a measure of rotational speed or rotational frequency.

In SI units, 1 RPM = 2π/60 rad/s for rotation speed, and 1/60 Hz for rotational frequency.

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Can I use a resistor to slow down a DC motor?

I have a few DC motors of 1.5 V and 9 V and need them for some applications. These motors run at a certain speed (RPM,) but I need to slow them down. Will it be a good idea to connect a resistor in series with the motor and the battery in order to…
Xlam
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Is it normal that a 12 V DC motor changes its RPM depending on its orientation?

I got a 40mm brushless DC fan from SHENGSHIDA which is rated at 12V and 0.15A. I supply it with 5V from a Raspberry Pi. I noticed that the rotational speed of the rotor changes depending on the position to the ground. When the airflow is directed…
Molitoris
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If a high rpm motor is run at lower rpm, will it produce more torque?

I did the following calculations: Max current = 1.2A, Max voltage = 12V Then power = 14.4 watts = 0.019hp Rpm = HP * 5252 ÷ torque I need a torque to 2kgf-cm = 0.144 lb-ft Gives rpm= 698. Thus this means if I put load(mechanical) on the motor, it…
Aether
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Need to increase the amplitude of op-amp output

I'm using this circuit to measure the RPM of a DISC rotating at 24000 rpm. This circuit is working fine. But the problem is with amplitude. It should be of 4.2V, but actually is of 2V as shown in picture below. The question is how to increase the…
mastermind
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Want Square Waves based on Injection Timing of 4-Stroke Engine

Recently, I am working on ECU of CNG Auto Rickshaw having 4 Stroke Engine. Here, Image shows the Engine of Auto Rickshaw. I have already taken reading of MAP, TPS and RPM. And now I am working on Injection Timing. For that, I am taking signals from…
karanrp
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DC motor RPM accuracy/precision

Small, permanent magnet, brushed tri-phase DC motors ('toy motors') may give a speed/torque curve, or at minimum a no load RPM. What is typical RPM accuracy relative to the datasheet, and how precise is its RPM (i.e. its variation) from run to run?…
abc
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How can I connect two motors in parallel with different RPM and voltage?

I have a kid's electric toy car with a 12 V battery and 2 DC motors (Model: RS380/6 V & 12 V with 15000 RPM) connected to battery in parallel and to wheels using gearboxes. For some reason, the 6 V motor burned out. I replaced it with another 6 VDC…
Zain
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Average data transfer rate

I am learning computer architecture and organization I am stuck in the following question. Consider a hard disk with sector size 1024 bytes, 5000 tracks per surface, 64 sectors per track, and 8 surfaces. If the disk platter rotates at 10,000 rpm,…
Anshul Gupta
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Alternator output rating

Overview: I am currently working on a project that requires a 24v alternator, which is powered by a mower engine. This engine in particular runs around 3,000 RPM, and does not exceed 3,200 RPM (based on a few quick tests with a cheap tach). The main…
Birts
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ratiometric hall effect sensors outputs at high RPM

Im using an allegro A1308 linear ratiometric hall sensor to measure the rpm and angular position in a shaft rotating at 20K rpm. My magnet is a 2mm dia 1120 mT magnet placed at around 15mm from the shaft. The TEAG(total effective air gap) of the…
harizas
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Is there an economical 2-3 RPM 120v motor with speed control? Or what components could I use to achieve that scenario?

I've got a mechanical design for a piece of catering equipment and I need to figure out a way to achieve some variable speed control for a slow RPM motor. This is a direct drive application (imagine the motor shaft connected to the center of a lazy…
cadgirl
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BLDC motor poles versus Torque and RPM

How to calculate the cost of a BLDC motor? Assume I need 24 stator coils of height 10 mm and width 5 mm. Is there any formula for torque comparison with increasing the number of poles?
Rohit Bharati
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DC motor characteristics and control

I don't have a lot of experience into detailed / calculated selection of DC motors based on their specs. Now, I'm starting to do it for robotics competitions as I'm progressing to more serious ones. My questions are: I know that when you increase…
Vishal Dhayalan
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Correct PWM frequency for motor

I am using 4500 RPM motor.To be specific,this is the motor I am using https://www.robomart.com/4500-rpm-high-torque-dc-motor. I am using Cytron MD10C motor driver to drive it.The PWM source is Raspberry pi.What is the range of frequency for PWM that…
user81367
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Right power supply for DC motor with load

I am trying to turn a disc of 10" of 20kg with a DC motor. I would like to get at least 1200 RPM. The motor is an Ampflow A28-400 and the power supply I am using is an adjustable power supply by Versatile Power called BENCH 30-33 XR. Although the…
Sun Jang
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