Questions tagged [motor]

An electrical actuator that converts electrical energy into rotational motion or sustained linear motion (linear motor). There are many types of electric motors. If the specific type of motor is known, it is helpful to use or add a more specific tag, such as dc-motor, brushless-dc motor or induction-motor.

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Controlling multiple motor drivers with one Arduino

I have one Arduino and I need to be able to control five to seven 12V motors that each draw about 4 amps. Would I be able to use four Sabertooth 2X5 Regenerative Motor Drivers for this? Each driver ...
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3answers
4k views

Control hacked servo motor speed using L293D and PWM

I've got a L293D and a PIC16F877A outputting PWM. Not real PWM, just using Timer0 to turn ON a pin for 2 ms and OFF for 18 ms (total of 20 ms period). W.R.T. to the above schematic I got ...
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4answers
34k views

What is back-emf: counter-electromotive force?

Could someone knowledgeable on the subject explain what exactly is this back emf? How is it caused in a motor/generator, which components and which effects determines it?
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1answer
930 views

Is this galvanic isolation?

I'm doing a project which consists of 2 big parts: a control part (a microcontroller with I/O pins expanded, USART-to-USB, a RTC, an EEPROM, a LCD) working @ 5V and an actuators part (optocouplers for ...
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2answers
895 views

Galvanic separation between a microcontroller and a motor driver

Is it possible to achieve galvanic separation between a microcontroller and this driver . It's a dual full bridge driver and I'm going to parallel it's outputs (consequently the inputs and the sense ...
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1answer
2k views

how to control brushless dc servo motor?

I have one of this motor and would like to make a controller for it ( just a speed controller with regulator that change speed from zero to maximum. ). I know micro controller and embedded system, but ...
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2answers
6k views

Cannibalizing a printer, how to figure out what some of the parts are/do

My son an I are attempting to cannibalize a printer a HP LaserJet 1300. It used to work and print, but it was low on toner and the company we got it from replaced it instead of buying new toner. So, ...
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5answers
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get a DC motor from household device?

I was wondering if there are any common household devices from which I can get a small DC motor (I have a 9V battery...) to use with a breadboard? It'd take me a long time to buy one so I was hoping ...
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1answer
555 views

Need help understanding and interpreting IGBT datasheets

When it comes to motor control, I understand that we have the option of using discrete MOSFETs or IGBTs. Also, there are some products in the market where 6 IGBTs are placed in one single package, ...
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2answers
8k views

Which voltage uses the “Kv” parameter in a BLDC (Brushless DC) motor?

According to the definition of a BLDC by Wikipedia: \$K_V\$ is the motor velocity constant, measured in RPM per Volt (not to be confused with "kV," the abbreviation for "kilovolt")[6]. The \$K_V\$...
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4answers
9k views

How can I sense the motor's current?

I need to drive a DC motor @ 24V, 6A with a MOSFET. How can I sense the current that the motor is drawing with a microcontroller? I have to know when the motor is stalled.
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3answers
5k views

How do I know where I need decoupling capacitors?

I'm building a motor driver shield for the Arduino. Here's the schematics (please forgive the messy layout): And here's the PCB layout: I'm testing it out by breadboarding it while running a simple '...
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3answers
69k views

How to drive a MOSFET with an optocoupler?

What's the proper schematic for driving this MOSFET from a microcontroller pin through this or this optocoupler? The MOSFET will drive a motor @ 24V, 6A.
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1answer
238 views

Suitable motor for pic WAKING project

Since my sleeping is very deeply, I can't wake up with alarm clock, I thought for a simple PIC-microcontroller project to wake me up. I will suspend a "bucket" full of water from the ceiling above my ...
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1answer
436 views

Maximum switching speed of a motor

If I have a MOSFET (or a number of paralleled MOSFETs) driving a motor, what determines the maximum bandwidth (PWM frequency) at which I can excite a motor phase? Is this only a function of the total ...
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2answers
266 views

Circuit design for controlling 6 individually selectable motors

I need to control 6 of these DC motors from an Arduino. If I needed to control them entirely independently, the obvious choice would be 6 H-Bridges, but I have somewhat relaxed constraints, so I'm ...
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5answers
34k views

Braking a DC brushed motor

What would happen if I short the terminals of a DC motor together while power is disconnected but it is still freewheeling? According to several sources, it would brake the motor. This makes sense. ...
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1answer
384 views

I am thinking of designing an electric car and am wondering about the best way to drive the wheels

I'm thinking of a light cart - barely enough room for one person and the batteries. What do you think would give me the best battery life? I am thinking a (brushless?) motor with the input voltage ...
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4answers
2k views

Why do we need brushed motors?

Looks like brushless motors are more convenient - no brushes means no maintenance required. For example, power tools manufacturers often cite that graphite brushes need to be replaced every 50 hours ...
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6answers
3k views

What causes “hard working” growling sound in a heavily loaded electric motor?

From my experience just any electric motor when under huge load would make recognizable growling sound. This would happen regardless of the motor type - brushed/brushless, AC/DC, small size/huge size -...
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1answer
2k views

how to read battery spec?

I window shopped for a small size battery. On the battery specifications, there are: capacity(mAh) : 85mAh Pulse Current(mA) : 190 Cycle Life(Times) : 300 What does Pulse Current mean? Does it ...
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1answer
3k views

Using a triac to switch on/off a single phase AC motor

I want to use a triac controlled by a suitable optoisolator such as a MOC3020 to switch a single phase AC motor on and off, like the ones you'd find in a typical desk fan or a blender or similar. I ...
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3answers
238 views

Connect a 8 V motor to a 16 V battery

I am hacking a vacuum cleaner robot by trying to control the motors with an Arduino. I have then two 8V motors, each one needing from 50mA (when the wheel is turning free) to more than 1A (when the ...
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3answers
2k views

How is precise control over motor as in Segway achieved?

When I read about Segway I always wonder how such precise control over the wheel motors can be achieved. I mean if the rider wants to go one foot forward, then one foot back, he leans forward, the ...
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2k views

Can I get a pair of schottky diodes in a single chip?

I'm building a motor driver circuit, and am looking at diodes to clamp the output voltage between the supply rails. Apparenly, I should use schottky diodes for this purpose. My question is, are there ...
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1answer
510 views

With the case of stepper motors, what correlates to the max RPM of the individual unit?

I'm looking at a few different stepper motors for an engineering project I'm working on, and I'm attempting to tease out any correlations that a stepper motor's stats would have with its maximum speed....
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6answers
157k views

What is a “digital” motor?

Dyson keeps going on about their new "digital" motor. What is a digital motor? How can a motor be digital, if it is inherently analog? Is it just marketing doublespeak?
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2answers
2k views

Need oscillating servo/stepper motor guidance

EDIT: Additional Information below original post... Looking for a 360 degree servo motor that has adjustable control for timing of steps (or at the least timing per full oscillation) and can support (...
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3answers
1k views

Best way to drive a 20 kg object on a turntable? [closed]

I need to rotate an object about 20 kg's in weight, 360 degrees. I'm thinking of using a stepper motor with some kind of rubber wheel pushing along the rim of a lazy-susan. Geared or belt solutions ...
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2answers
2k views

Powering a Servo: Do I need a separate power source?

I have a project that utilizes two strong digital, coreless servo motors. Whenever I use DC motors, I usually need to have separate power sources for both the microcontroller and the motors (due to ...
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3answers
1k views

A “hobby” grade linear motor

Can anyone recommend a hobbist linear motor? The motors are often described as being a rolled out version of a DC motor (is that true btw). If this is the case then how does one "drive" a linear ...
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2answers
1k views

AVR Assembly with Servo/Motors/Etc

So I've been learning AVR assembly in my own time, I rather like it and I understand registers/counters and such. But the problem is...most of the websites I read online/tutorials don't really talk ...
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2answers
7k views

Two Wire Servo in RC Car?

I took apart an RC car recently and found 2 sets of motors. The rear wheels (left) seem to run off an electric DC motor which is understandable. The front wheels (right) I expected to be controlled ...
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2answers
3k views

Controlling a geared motor

I've used small high speed dc motors by just wiring them to a battery and potentiometer, but i've heard a lot of talk in these forums about motor controllers and h-bridges, and I don't fully ...
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2answers
2k views

DC motor Armature and Field back emf

In a motor where both the field and armature are wound there are at least two possible control scenarios. The field winding can be excited with constant current and the armature voltage controlled, ...
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2answers
2k views

Low voltage motor with arduino

Would it be safe to use a 1.5 volt motor with the adafruit motor shield? It is rated for 4.5 to 36 volt motors so I am unsure what will happen. Also, what would be a good way to determine the voltage ...
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2answers
1k views

predicting brushless motor rotation direction?

When connecting a brushless motor to an ESC, we are taught to apply power and switch two of the wires if the blade is spinning in the wrong direction. Is it possible to predict the blade rotation by ...
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3answers
11k views

3-phase Motor Speed Controller

Background If you look at my profile description, you'll see that I'm involved in building and wiring up Carnival floats that are powered by an 800KVA, 415v, 3 phase Generator. Electrically, they ...
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1answer
816 views

Detect PWM Duty Cycle in Hardware

How would I go about detecting at motor controller level, that my PWM signal coming from my microcontroller is at 50% duty cycle. I would like to design a dead band into my motor controller so that I ...
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1answer
1k views

AC/DC motor stall protection after the fact

I am wondering if there is a circuit I can add to a low voltage DC motor or a 110VAC motor that will cut the power if the motor stalls. I service coin op redemption games and on a few games these ...
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3answers
590 views

Stepper motor substitution

I need to find a inexpensive replacement stepper motor and I am wondering if all of the specs need to be matched or are there some that don't need to be exact. Right now they are using a six wire ...
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2answers
2k views

Builiding a catapult that runs continuously with a motor

I need some ideas for designing a catapult that runs on a motor. Basic requirements: able to launch a cookie 30m, capable of continuous operation, fits within a 0.4 m × 0.6 m × 0.4 m high box, allows ...
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2answers
7k views

A proper way to determine correct voltage of unmarked components?

My kids have been tearing apart a number of different gadgets, from RC cars, to toys, to coffee makers. There are a variety of cool little motors and lights in these devices that we would like to use ...
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3answers
272 views

How to release ice cubes out of a box?

For a University project I have to build a small box containing ice cubes. The box is a shoe box, isolated with newspaper and aluminium foil, cooled by thermal packs. In this box I want to store ice ...
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3answers
525 views

Budget alternative to fancy linear slide

I have been checking out nice 1D linear slides such as this and this and this. Especially the first one is really nice since it has a built in encoder and a controller with RS232 interface. However, ...
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1answer
918 views

Does anyone know where to find the datasheet for an Electrocraft Model E19-2 motor?

More details from the motor casing: Electrocraft Model: E19-2 Serial: A01314 Part #: 0643-08-013 It looks like it was made by Robbins Myers Motor & Control Systems Division. In case anyone is ...
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2answers
1k views

DC Motor driver with Arduino

I made a simple motor driver as suggested here ...
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4answers
447 views

Suitable motor for robot

I'm planning on building my first robot using an Arduino. It's going to be a small obstacle avoiding robot powered with a 9V battery. What should the voltage of the DC motor used in the robot be? Also,...
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2answers
19k views

Motor driver using only a 2N2222 transistor?

Is it possible to build a motor driver using only a 2N2222 transistor? If yes, then how?
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2answers
5k views

What determines the speed of a homopolar motor?

What determines the speed of rotation of a homopolar motor?