An electrical actuator converting electrical energy into rotational motion.

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11
votes
3answers
998 views

Why should I worry about a motor causing my supply voltage to shoot up when the back-EMF can't exceed the supply voltage?

I have heard people say that in motor control circuits, one must take precautions to keep the motor from feeding back into the power supply, causing the supply voltage to rise, consequently breaking ...
13
votes
1answer
5k views

How can I implement regenerative braking of a DC motor?

I know that many electric cars are able to convert the momentum of the car into stored energy in batteries, rather than convert it to useless heat at the brake pads. How does this work? How can I ...
4
votes
1answer
6k 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?
11
votes
1answer
4k views

How can I measure back-EMF to infer the speed of a DC motor?

I'm interested in measuring the back-EMF of a motor to determine a motor's speed because it's cheap and requires no additional mechanical parts. How can I measure the back-EMF when I'm driving the ...
8
votes
3answers
16k 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.
17
votes
11answers
4k views

I'd like to learn how to make my own USB gadgets

I've been writing Linux character device drivers for other people's stuff for some time. I'd like to find a new hobby and the thought of making my own USB gizmos seems really neat. I would be ...
11
votes
4answers
2k 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.
7
votes
1answer
370 views

Ground noise and voltage drop problem

I have an RC device powered by a 3.7V poly battery, which includes a motor and a 40KHz sonar. The voltage across the sonar sensor is amplified and then adc-ed. The motor is driven by a 2KHz PWM. When ...
6
votes
3answers
3k views

Explanation for Differing Stator Winding Orientations

As a layperson, I'm trying to understand the basic configuration for an induction motor or generator. I've looked at many diagrams and photos/cutaways of stator wiring and I've noticed two different ...
0
votes
1answer
326 views

Alternative to easy-driver (or adafruit motor shield ) on breadboard [duplicate]

I'm up to implementing bipolar stepper drivers with STEP and DIRECTION inputs just as like easydriver and pololu stepper drivers but that on breadboard.Earlier I was using L293D to do that , but it ...
7
votes
4answers
4k views

DC Motor control with an Arduino

This might be a simple, silly question, but I am wondering why I can't just connect a DC motor to an arduino board to have it running. One pin to the ground and the other to one of the PWM outputs. I ...
8
votes
3answers
879 views

Is it valid to consider back-EMF in a DC motor equivalent to increased inductance?

I know that back-EMF can be considered as a voltage source in series with the motor which is proportional to speed. This is the common understanding, and I totally get it. Before I understood this, I ...
4
votes
3answers
2k views

Detecting dry-running of water pump

What are some reasonably reliable ways of detecting that a water pump (electrical motor based) is "dry running", i.e. no water is passing through the pump either because there is no water available at ...
0
votes
0answers
48 views

Which would be the best option for driving the 3/4 axis stepper motor for 3D printers?

I have researched a bit over google and reprep websites and come across different circuits/methods to drive the stepper motors. Being a student only , I have budget issues and I want it to be less ...
7
votes
3answers
7k views

Control differences between ac induction motor and brushless dc motor?

I have a fairly solid background in industrial AC motor control (soft starters, VFDs, etc.) but something that I'm certainly NOT well versed in is brushless DC motors... the type found in every hard ...
3
votes
3answers
2k views

Using a motor to open doors

I have made a wooden case to hold both my Xbox 360 and my PS3. It's as wide as both consoles laid down next to each other and as high as the console. it has 2 doors on the front, one for each console. ...
2
votes
3answers
697 views

What is good device for generating vibrations, offset weight motor or solenoid or some other?

I am building a vibrating device for that I am thinking to use a solenoid for vibration. The solenoid will be used such that device will be mounted in the floor and when a stick is put over solenoid, ...
2
votes
1answer
3k views

What power motor should be used to power a Segway-like device

I am planning on building a personal transportation device which will either be a skateboard with a motor etc or a Segway-like device. I will have two wheels and must be capable of getting me to move ...
0
votes
2answers
875 views

15V 3A dc motor PWM frequency setting

What is a suitable frequency for 15V/3A DC motor? Is there any effect on the motor when the frequency is changing? I am confused with this until now and the Internet shows a lot of theory that ...
16
votes
3answers
2k views

Why don't all motors burn up instantly?

A motor rated for 3S (11.1 V) has an internal resistance of 0.12 ohm. The maximum current is 22 A. 11.1 V / 0.12 ohm = 92.5 A Doesn't this mean ...
7
votes
3answers
851 views

Capacitors and motors

Every RC car I've cannibalized has had a small ceramic capacitor soldered on to the contacts of the motors. What is the purpose of having this? What happens to the performance of the motor with out ...
6
votes
5answers
7k views

Computer controlled water valve

I'm working on a computer-controlled indoor waterfall. One of the requirements is to be able to change the water pressure via computer interface. I've googled all day long and can't seem to find a ...
3
votes
2answers
3k views

AC fan speed control

I use this fan to cool my room, but sometimes it is too fast and I have to frequenctly turn it on and off to keep normal temperature. Maybe it is possible to reduce the speed by connecting a resistor ...
9
votes
4answers
614 views

Methods to accurately move an object across a 2-D plane

This is the opposite/complement of my previous question, which concerned measuring the precise position of an object as it is moved/drawn by someone over a short duration. Assuming I use one of ...
10
votes
2answers
4k views

Why connect capacitors to motor body?

So I've found a motor circuit which looks like this: Since many users here believe that my hand-drawn circuit schematics are in fact pictures of flying spaghetti monster, I'll also provide a ...
7
votes
2answers
1k views

Can Arduino Mega handle 6 motors independently

I wonder if anyone can help me I am modifying an ROV and thinking of using Arduino Mega I am new to electronics and robotics and wonder if the Arduino Mega can control 6 DC motors independently as ...
7
votes
5answers
434 views

Good motor supplier?

I'm looking to start a few different projects and stock up on some basic components - I was just wondering if anyone knows a good supplier of DC motors, stepper motors and servos? I'm in vicinity of ...
1
vote
2answers
387 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 ...
8
votes
4answers
2k views

Why use DC motors for driving elevators?

This New York Times article says that on November 14, 2007 Consolidated Edison Company was going to end supplying direct current to the remaining several buildings that used those to run elevators. I ...
6
votes
3answers
651 views

Why Have Non-Zero Timing on a BLDC?

I've heard you can go faster in one direction if you adjust the timing, but do not understand why? I have a sensored bldc motor with a 30deg shift of the hall-effect sensors, tried going forward (CCW ...
4
votes
2answers
988 views

Can I use a DC SSR that is switched by a PID controller to control the speed of a 12 V DC fan?

This is my first post here. Let me start by saying that I do not have an engineering background. I tinker with electronics in my spare time (Arduino, solid state low-power guitar amps, etc.), but I do ...
4
votes
2answers
664 views

DIY small motor that turns for x seconds every y seconds

I'm a civil engineer, hiker, and hobby photographer. I am trying to build a little device that gently turns a small motor on every x seconds, keep it on for y seconds, and stop it for z seconds. For ...
4
votes
4answers
386 views

Overclocking my toothbrush

I use these toothbrushes: http://www.amazon.com/Oral-B-Advanced-Toothbrush-Vibrating-Bristles/dp/B00336EUV8 They tend to run out of battery quite quickly. I'm happy to keep buying more because ...
4
votes
2answers
3k views

How to find out whether I have a unipolar or a bipolar stepper motor?

I have one stepper motor. There are six wires coming out of that. How can I find out weather I have a bipolar or a unipolar stepper motor? Note: Related, but not a duplicate: Unipolar and Bipolar ...
4
votes
1answer
887 views

Arduino Speed Controllers for RC Cars

This may be a lame question but, Speed controllers on big RC cars can they be controlled from Arduino? If yes, do they have a standart? do I control them using PWM values? What should i look for if I ...
3
votes
1answer
626 views

Recommend motor type to turn baby rocker, into auto-rocker

Would like to convert a baby bouncer (like this one), which requires continuous manual effort to rock it, into one that use electro-mechanical means to auto-bounce. However, my aim is to make these on ...
2
votes
1answer
163 views

DC motor starting and stopping

I'm powering a motor, and instead of rotating at a constant rate, it rotates roughly a third revolution every half second or so; the rotation keeps starting and stopping. There's no load on the motor, ...
2
votes
1answer
162 views

How to interpret diode-mode readings from a multimeter

I'm using this multimeter to examine a heat gun fan. The fan has four contacts placed in a circle (well in a square inside a circle). Two opposite each other are labeled ...
2
votes
3answers
727 views

AC motor Low RPM problem

I'm working on a controller for ac induction motor and it's spec is given below. I could control the speed without any trouble at higher speeds like 2000 rpm and above. I'm using TRIAC phase angle ...
2
votes
1answer
777 views

How to tell if brushless DC motor is wired delta or Y?

I have a brushless DC motor I'm working with, do not have any spec. sheets for it. How can I determine if it's wired in delta or Y formation? There is nothing on the label that indicates this. ...
1
vote
1answer
442 views

Need help on speed control of single phase ac induction motor

I'm working on a project "single phase ac induction motor speed controller". The spec of the motor that im going to use is 230v,1/8hp ,8000rpm@no load I want to know whether it is possible to ...
1
vote
1answer
135 views

Electromotor for large platform

For a design project I am designing a plastic platform with a steel construction under it, which has a diameter of 4 meters which is able to support 15 persons. The platform should be able to rotate ...
1
vote
1answer
453 views

Automatic Rotating Platform [closed]

I would like to build a very simple, circular wooden platform that rotates automatically - no stopping. The torque is not very important, as it doesn't need to support much weight. As far as rpm, ...
1
vote
2answers
961 views

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 ...
1
vote
2answers
2k views

L298 Motor Driver spinning motor only one way :/

i just made a motor driver circuit on a veroboard to use with my arduino but the problem is l298 spinning motor only one way. here is the code it was supposed to spin motor forth and backwards every 2 ...
0
votes
0answers
59 views

Two wire circuit of H-bridge as Bipolar stepper driver for CNCs and 3D printer and stepper motor vibration and noise issue [duplicate]

So after searching a lot and looking up every Jack and Jill's website for 3/4 axis cheapest DIY stepper driver for the 3d printer and CNC. I have come to the conclusion that using L293d with ...
0
votes
1answer
138 views

Useless Machine geared motor

I am attempting to build a “Useless Machine” from scratch. Here is a video of the device: http://www.youtube.com/watch?v=Z86V_ICUCD4 . Also [if you want to], Google "The Most Useless Machine EVER! ...
0
votes
1answer
176 views

Interactive Art with Wooden Mirrors - How are the pixels controlled?

http://www.youtube.com/watch?v=BZysu9QcceM This video shows a mirror made up of moving wooden pieces. Please have a look. He achieves different intensity levels by motion of the wooden pieces and ...
0
votes
3answers
1k views

how to find out wether the stepper motor is working or not?

I have unipolar stepper motor with 6 wires and i have made controller circuit but when connect controller to stepper motor it is not working.. So i want to know weather stepper motor is working or ...