Tagged Questions

0
votes
0answers
50 views

Choosing the correct brake resistor for DC motor

I have a DC motor running on 24VDC rated 150W (~6,25A), how do I calculate the correct brake resistance?
2
votes
1answer
75 views

Control old printer motor with position ring

I purchased two old printers at a garage sale today in hopes of dismantling them and playing around with some stepper motors. After tearing both of them apart I discovered that there are no stepper ...
1
vote
1answer
55 views

Which electro motor to use for steering a kite? (guestimation marathon)

I'm doing a pet project in which I want to fly a kite from my computer. For this to happen my plan is to build a little box hanging under the kite which includes a raspberry pi (connected to my laptop ...
0
votes
2answers
57 views

Why is this electro motor going slower?

From an old dust buster I've got this electro motor, the included battery pack and the charger: I ripped everything apart (the dust buster was broken) and the motor still works. After playing ...
5
votes
2answers
140 views

making a dc motor sing under load

I have a battery operated toothbrush that I want to generate notes with using PWM on the motor. The microcontroller used is an Arduino for testing and am able to get a bare motor to generate tones. I ...
8
votes
4answers
700 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 ...
0
votes
2answers
137 views

DC Motor control

I am using a DC 24v scrapped photocopier motor for a table fan. To save energy, it's ON for 2 seconds and OFF for 3 seconds using MCU. The fan keeps rotating during the power off state. Is this a ...
0
votes
1answer
117 views

How can i tell what the voltage,watts and Brake Horse Power is on my mobility scooter motor is as it does not have any info stickers on it at all? [closed]

Can someone please tell me how I can tell how much Voltage,Wattage and brake horse power my mobility scooter motor has? How can I test this?And what with? It is a 4 Mph scooter and uses 2 12V 33Ah ...
3
votes
1answer
364 views

Half-H bridge or low-side MOSFET for PWM motor control

I'm driving a DC motor (12 V, approx. 4 A) and I need to control the speed by PWM but I need one direction only and braking is not required. My question is: is there any advantage to using a half-H ...
-1
votes
2answers
520 views

How to make a touch screen device with android OS?

I am planning to make a device which has a touch screen LCD. I have searched for solutions and i think if this device has android OS could be use for many applications. This device will be used for ...
3
votes
1answer
322 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 ...
7
votes
6answers
347 views

Why are battery-powered appliances and tools specified in volts? [closed]

"Powered with a suction of 18 volts" Isn't this just a nonsensical "bigger is better" measure? The thing you really care about as a customer is the motor's torque or power or RPM or something ...
5
votes
4answers
431 views

What action is responsible for speed changes in a brushless DC motor?

Hi and thanks for looking! Background As a hobby, I enjoy tinkering with basic circuit building (often using Arduino) and lately I have mixed this hobby with another hobby of mine: building RC ...
1
vote
1answer
479 views

220VDC motor slow and jerking

I'm troubleshooting issue of a motor from a washing machine I bought from a garage sales. Based on the service manual, I'm suppose to replace the motor assembly. So I decided to take a closer look at ...
0
votes
2answers
387 views

Driving a DC motor forwards and backwards with a PIC

Say I have a DC motor which runs clockwise when current flows in one direction, and counter-clockwise when the current flow is reversed. I have 2 lines going in my circuit, +5V and ground. I have a ...
4
votes
4answers
348 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 ...
-2
votes
1answer
446 views

charge a mobile using a dynamo

I am making a project to charge a cell phone battery using a dynamo,but i don't know how to start about.also let me know about the power ratings of the dynamo to be used for charging a 3.7V,1000mA ...
3
votes
2answers
196 views

Which parts of this rotor can be made out of plastic?

I'm asked to redesign a rotor, by making as much parts of it as possible out of plastic. The issue is its weight, we want to make it as light as possible. Especially the shaft & axis of it is the ...
8
votes
3answers
485 views

shooting object by using a DC motor

This is not directly electrical, but I am working on making a real life version of a coin block from Mario. Basically I use an LDR and to detect if someone punches the block and then use a transistor ...
4
votes
1answer
184 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 ...
1
vote
2answers
122 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 ...
4
votes
3answers
796 views

Isolating motor control signals from microcontroller from high voltage/current lines

We need to design an integrated DC motor controller/driver, which will be under microprocessor control. Due to space requirements, either the digital and analog circuitry will be on a single PCB ...
2
votes
2answers
1k 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 ...
1
vote
2answers
406 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 ...
3
votes
2answers
538 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, ...
5
votes
1answer
414 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 ...
7
votes
2answers
1k views

Methods of filtering noise caused by DC brush motors

I am looking for any information that would help me reduce the power rail noise and EMI of DC brush motors. I am building a robot that is powered by 2 x 250 W 24V DC motors. Thank you in advance
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 ...