Tagged Questions

A common actuator in robotics; it's usually made of a static magnet (stator) and a set of moving inductors, acting as electromagnets, connected to the circuit through brushes. Brushless motors use phased clocks with electronic circuitry to generate motion.

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1answer
17 views

Torque control with H-Bridge via direction pin

Using the LMD18200 (H-Bridge) and the LM3524D (PWM regulator) I should design a torque regulation. I've found a circuit in the LMD18200 datasheet which uses the current feedback to adjust the PWM. ...
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1answer
49 views

Digipot for DC motor

I am going to use a 3V DC motor (operating voltage 1.5 to 4.5V DC) and MSP430G2553 microcontroller. So which digital potentiometer should I use to control the speed of the DC motor?
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1answer
47 views

Jack type for a 12v DC motor

I have an Arduino with a motor shield and I use it to power 4 different DC motors. Motors are connected to the shield through a screw terminal. Since I am in the prototyping step, I am moving them ...
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0answers
17 views

Keeping two wheeled wall following robot straight [migrated]

I have a two-wheeled (two DC motors) robot that needs to follow the wall beside the robot. The issue is that the DC motors spin at different rates (because they are not identical, of course), so the ...
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1answer
32 views

Comparison of the efficiency of DC motor current limiting / control methods?

I'm using the wheels and motors of an RC toy car as a simple robotics platform. The car has 2 motors, one drives the back wheels, the other steers the front wheels. The steering motor is stalled by ...
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1answer
64 views

DC motors, AC motors, and Kv

As I understand it, DC motors have Kv values because their speed is determined by the applied voltage. AC motors don't have Kv values because their speed is determined by the frequency of the AC ...
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1answer
76 views

Measuring DC motor voltage with an oscilloscope

My current setup involves an analog controller board that is driving a DC motor and I would like to monitor the voltage being applied to the motor at all times. How do I physically connect the ...
0
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1answer
47 views

Beaglebone Black PWM Driver for 12VDC 1.05A Motor | Drive from Positive Side

I have several 12VDC 1.05A pumps I am using in my hombrew system which I would like to drive via PWM on my BBB. Each one will have a hall effect flowmeter attached so that I can get flowrates, totals, ...
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2answers
93 views

Current reading, how does it work?

For a project I'm using an Arduino to drive a motor using a special pcb. In this board there is also a way to read the current drawn by the motor. Although I have the schematic I'm not 100% how this ...
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0answers
37 views

PWM for my air-compressor 15 Amp dc-motor

I have read some similar questions but didn't get the answer for mine. I want to make a viair 12v compressor run at a low pace to fill some tires very slowly drawing as few amps as possible. Could I ...
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0answers
54 views

Stepper motor to replace brushed DC motor to be used to start a gas engine?

I'm trying to decide if it would be possible to use a stepper motor to replace a current 12V DC brushed motor that is used to turn over a small (~149cc) gas engine for starting. The reason why is, I ...
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1answer
45 views

Current usage with multiple PWM controlled motors

I have a circuit that can use 25 A of current max, it is on a 25 A fuse. I am looking to control 4 DC brushless motors using ESC's. The trouble is that the motors are rated at 7A max current. I know ...
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0answers
37 views

PWM and flyback diode dependency

I have to choose components for a pcb motor driver, there is a dependency that I have to take into account between the PWM frequency and the speed of the flyback diode? If yes, what it is? Thanks
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2answers
84 views

Will these heatsinks be sufficient for my mosfets?

I need to control 10 12VDC motors at ~25Amps, so I decided to make my own mosfet H bridges to control it ( with 2 n chan et 2 p chan ). I will need 10 H-Bridge, so 40 Mosfets. ( 20 n chan and 20 p ...
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vote
3answers
57 views

HEXFET PWM motor driver does not work

I'm trying to drive a motor for an academic project, using the circuit in the image. The STM32F4 Discovery board that I'm using in this phase of the project produces a 30Khz PWM at 3V, that is correct ...
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0answers
64 views

Arduino with 6 motors controlled by Android device

For our first year engineering project, we are creating a guitar tuning device. We will need to control 6 motors, each turning a small knob (<1 inch) against a 10-20kg string tension. Manually ...
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1answer
84 views

High Torque Brushless DC Motors in Small Package

I have a particular set of requirements that call for a relatively high stall torque for the space available (300 ozf-in for < 8cm length of motor). The motor would be operating at a relatively low ...
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3answers
581 views

Locking up a DC motor with constant supply a bad thing?

I am working on a little pen plotter project and for one of my motors (which supports the pen) I have used a small DC motor obtained from an old DVD drive. I have noticed that if I supply a constant ...
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0answers
80 views

How Can I Slowly Turn Container With Electric Motor

I am wanting to slowly turn a jar in the horizontal position -- like a hot dog at 7 eleven, only no heat or stepping required. The idea I currently have is to use 2 dowel rods with a low RPM DC ...
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0answers
99 views

I think I have burnt my 24V DC motor

I had a 24V DC motor connected to a Polulu motor driver which was connected to an arduino uno board. I accidentally connected a power supply instead of a volt-meter to both ends of the motor while in ...
5
votes
5answers
283 views

Can a motor's movement be improved to any arbitrary resolution?

For a project that I'm working on, I need motor rotation at extremely small increments -- my desired resolution is about ~0.15 degrees per minimum rotation step. Of course, most motors of reasonably ...
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2answers
139 views

How do you control 130-size DC motors with an Arduino (seemingly 20A DC motors)?

I'm a little confused on specifications and limitations here... I have 3 (130-size, I believe) DC motors I'm attempting to control with an Arduino. They are running off of a 7.2V NiMH battery pack, ...
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1answer
66 views

Am I misunderstanding the specs of this solar panel or electric motor?

I've been trying to figure this out, but the answers I've come up with thus far have been counter-intuitive. The solar panel's specs are as follows: ...
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2answers
76 views

Convert perpetual magnet motor output to 5 volt DC

Disclaimer: Hi, I was in the neighborhood (StackOverFlow) and just noticed this cool site. I have had this general wondering for a while now and I am not sure if my question is constructive enough for ...
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0answers
28 views

Can DRV8837 be used to drive two DC motors in all four ways?

Knowing that some motor drivers do not perform well under low input voltages, I have found that this works well; but how do I drive motors in the following four ways: ...
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votes
1answer
153 views

Brushed DC motor control MOSFET selection

I want to control a brushed DC motor of the below specification: Motor: Permanent magnet DC brushed motor Voltage: 180V Current: 5 Amps RPM: 1500 The control method is PWM switching through a ...
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0answers
31 views

Power Supply Requirements [duplicate]

I am building some prototypes for my thesis but I am not sure how to buy the power source for them. I need to how to choose a proper power source(Volts, Amps, etc). The number of motors will vary but ...
0
votes
1answer
59 views

Using an H-Bridge like a comparator

I'm wondering if there's a way to use an H-bridge like a comparator- That is, if one input is greater voltage than the other, then the attached motor spins one way, and vice versa, and it doesn't spin ...
3
votes
4answers
685 views

DC Motor + 9 V battery + 270 ohm resistor = Nothing (Motor won't turn)

I'm trying to wire up a DC motor to a 9-volt battery with a resistor in between, and the motor just won't turn. It works if I connect the motor directly to the battery, but not with the resistor in ...
0
votes
1answer
64 views

How can I use 15 servos with arduino mega2560 without stepping down voltage?

How can I use 15 servos with arduino mega2560 without stepping down voltage? because I want to control 15 servos by one board (arduino mega 2560).
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votes
1answer
84 views

Using a brushless DC motor for generator

Is it possible to use a brushless DC motor as a generator? If we use the brushless DC motor in the following configuration, the brushless DC motor is used in front wheel of a rover/small car, and the ...
0
votes
1answer
60 views

Controlling high rating DC motor

In a robot, I need to use a (24 volts 5-7 amp) DC motor, which should be controlled by a microcontroller. Now, will I get a motor driver IC for such a motor? If not, what kind of circuit will help? I ...
0
votes
0answers
49 views

Variable Performance in DC Motor, Arduino, and L293D?

I have a pretty typical set up with an Arduino, a simple DC motor, and an L293D breakout board. I am using PWM to control the speed of the motor into the L293D enable pin. The DC motor is driving a ...
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vote
2answers
306 views

Why would I need a relay between a DC motor and my Arduino?

I was told that I should put a relay between my 5V motor and my Arduino. I asked why, but they didn’t know. Why do I need to separate them with a relay? The motor requires 5V and the Arduino provides ...
0
votes
2answers
59 views

Best way to step down (half) battery voltage for motors

I have a 4S LIPO battery 5800mAH at 14.8V and I want to use it to power some 7.2V motors I have. The Rover 5 Chassis to be exact (https://www.sparkfun.com/products/10336), the only problem I have is ...
1
vote
1answer
36 views

PMDC Motor transfer function

I'm doing an analysis of a PMDC motor and I don't understand something about the transfer function. I have the following equation: \$(K_t\frac{1}{((s* L_A) + R_A)})(V_I(s)-k_b\omega(s))= ...
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votes
1answer
27 views

Cumulatively excited and Differentially excited DC generator

Is a cumulatively excited DC generator long shunt or short shunt motor?
1
vote
1answer
91 views

Why can't we command two DC motors with just 2 relays for each in opposite directions with a same power supply? [closed]

We managed to control 2 DC motors with 2 relays for each one.It worked great except one thing: we couldn't make them turn in opposite directions at the same time .We noticed that there was a shot ...
0
votes
0answers
52 views

Create a negative volt with a 9v battery to run a 18V motor

I've got to create a small toy car running on a 9V battery to participate on a small race of 2x 15m and would like to use a bigger motor running on 12-18V. If I'd create a negative voltage it should ...
1
vote
2answers
144 views

Using the same power source for microcontroller (arduino) and rest of the circuit?

I have an Arduino, it controls a 6V DC motor and 12V DC solenoid (which only really needs 7V for what its doing). Originally I wanted to use 1 rechargeable 7V battery (or 9 or whatever the closest I ...
0
votes
1answer
53 views

Using dc motor as a sensor

I am thinking about an automatic blind opener/closer. In this idea I need to detect the end of blind while opening or closing to stop the motor. I don't want to use mechanical sensors on both side ...
2
votes
1answer
98 views

Eliminate PWM noise in PWM-driven bidirectional motor

I need to drive a DC motor with PWM, through a H-bridge. The controller can't generate PWM at ultrasonic frequencies with resolution I desire, and the low-end of the spectrum (~100Hz) may be too slow ...
2
votes
3answers
69 views

Current drawn by a permanent magnet DC motor

I have been working with PMDC motors for a while now. In these motors, as the load increases current drawn by the motor also increases. I was just wondering what is the theoretical reason behind this ...
3
votes
1answer
91 views

Difficulty getting motor to reverse

I am building a humane rodent trap, and require assistance. The trap works using an LED (not shown) and LDR (photoresistor). When the rodent walks over the LED, The LDR increases in resistance and ...
0
votes
2answers
147 views

H-Bridge Instant Death

I have a DRV8840 that I am trying to use. I have burned up about 10 of them trying to get it working. For this application, I need the H-Bridge to Current Limit and Brake the motor. Max current ...
0
votes
3answers
158 views

Connecting diodes to a motor in H-bridge

I'm attempting to design a three wheeled toy that is controlled by a remote connected with it via a cable. I first designed it with relays, however I had to change to transistors due to contrast ...
0
votes
1answer
84 views

Transfer Function: State Space for DC motor

General question on making state space equations for a DC motor. In the link below, why are both the electrical and dynamics equations 3 and 4 used to make a state space eqn.8, instead of combining ...
0
votes
1answer
46 views

How to regen a DC motor from the high-side of a boost converter?

I am planning to drive a 24v motor from a 12v battery, using a DC-DC boost circuit to generate the 24v and an H-bridge to PWM drive the motor. A problem arises when the motor goes into the regen ...
3
votes
1answer
404 views

Why does the potentiometer burn up in my setup?

I connected a potentiometer to my DC power supply (max 1A, 12V), and then connected a motor to the variable voltage side of potentiometer as well. The potentiometer is just 1K. When I tried using ...
1
vote
2answers
528 views

limit switches to control motor direction

I am trying to use two limit switches and two DPDT relays to control the direction of the motor. When the power is applied the motor should rotate one direction (direction for this question isn't ...