how to run a high voltage motor with low voltage Answered

Hi there, I just wanna know how to run a 12v D.C motor using a 9v battery, is it possible by using  voltage and current doubler circuits? please help me, as i want this knowledge for a project of mine

Question by VivekM12   |  last reply


Which Low RPM Gear Motor?

I am working on a robot that will have a grabbing claw, of sorts, and I'm not sure what gear motors to use to actuate the claw.  It needs to have significant gripping power, so the gear motor must be low-RPM and high torque.  The two best options I have found so far are these: 1. 12VDC Gear Motor, 7 Rpm 2-7/16" x 1-5/16" Dia. 2.  Tamiya 70110 4-Speed Crank-Axle Gearbox Kit   If I used the Tamiya gearbox, I would also have to buy higher voltage motors, so the cost of the two is approximately equal.  Because of its layout, I think the Tamiya would be easier to use, but I'm worried about stripping the plastic gears.  Also, I have a smaller Tamiya gearbox, and the axle has some play in it and is extremely noisy. The 12V gear motor, on the other hand, appears to be more robust and probably has metal internal gears, but it would make my robot a bit larger. Does anyone have experience with Tamiya gearboxes?  How do they handle high loads?  If anyone has any input on these two choices, or other motors you think would be even better, I'd really appreciate the help.  Thanks!

Topic by ben_k   |  last reply


Variable, low-RPM DC motor setup?

Hey guys, I'm hoping to build a motorized slider system for my DSLR camera. I'm going to build the slide from scratch and probably attach a motor with a pulley system to move the slide, this should give me the option of having the camera climb the slide if it's on a slight angle. I'm not extremely electronically inclined but I understand I will need a low RPM motor and a PWM unit to adjust the speed. I'm thinking RPM between 0.5 & 10 would be ideal. Could I buy one of these (http://www.aliexpress.com/item/12v-100w-pwm-speed-controller-motor-governor-DC6-15v-STP50n05-wholesale/1663330358.html) add a 12v battery and a 12v DC motor and call it a day? If this is the case, should I be aiming for a 10 RPM motor that I can turn the speed down on? Is a 12v battery/motor likely to give me reasonable torque for dragging a DSLR camera up a moderate incline? Battery life shouldn't be an issue as the longer the use the less RPM I'll need. Any thoughts would be much appreciated.

Question by tig5   |  last reply



Low Speed Motor?

I want to make a baby night toy with multi color LEDs and a rotation device. For which i need a low speed motor. Can someone help me find such a motor or give any idea on how an ordinary motor can be used for this purpose? thanks in advance for all the feedback.

Question by muhammajunaid   |  last reply


ac motor?

 i have an 3 phase motor with high and low voltage 3/4 hp 3450 rpm, voltage being 208,220,440  first time learning about wind power.Would i be able to use this for wind power generator

Question by time out   |  last reply



Slow down a DC motor?

Here is another basic electronics question for all of you: What is the easiest way to slow down the RPM of a small DC motor? Much appreciated!

Question by brandegor   |  last reply


RPM of K'nex engines? Answered

Does anyone know the revolutions per minute for the K'nex electric motor (grey one with mains adapter) and the revolutions per minute for the K'nex tethered battery motor (same as standard battery motor I think). Electric one is first picture, battery one is second picture.

Question by The One and Only   |  last reply


50k RPM with DIY Motor?

Has anyone built an electric motor that can reach 30-50k RPM? Would you think it is possible to build one?

Topic by Tyoon   |  last reply


WANTED: DC motor

I'm trying to build a wind turbine. If anybody has a DC motor from a old treadmill, electric scooter, etc. I would love to have it. The idea motor would be one with highest volts per rpm. That means low rpms and high volts. Let me know if you have something.

Topic by JSTArollin 


Use brushless DC motor (or stepper motor) as RPM sensor?

Hi all, I'm making an Arduino based digital instrument cluster for my 1980 XS400 motorcycle. all the old tach and speedo instruments are mechanical so I need to convert the spinning cable's rotation to digital RPM. I've tried IR tachs but I can't seem to get them to be accurate enough (the lowest RPM I could get out of them was about 375, which isn't low enough) I'd love to use a more mechanical means of getting the RPM. could I use a 3 phase DC motor to count RPM? if I can, how?

Question by AedanGraves   |  last reply



Motors for Quadcopters

Hi, I am looking to make a quadcopter as my university project and I kinda run in to some problems deciding which motor I need to choose. I was thinking to choose brushless motors as they are more efficient and they give more RPM. HOwever, my professor says that there's no point using brushless/stepper motors as u can get the same RPMs using brushed motors and its the same thing. Hence, can anyone please guide me which motor is best to use and why should I use brushed or brushless motors. I shall be very glad if someone guide me through it. Thank you :)

Topic by Bam Boy   |  last reply


Best motor for speed control - ( low rpm - spin 1Lb of coffee)

I'm looking for a motor can have its speed varied, down to 1 rpm if needed and that can be done with a simple circuit. I'm building a coffee roasters. I hear that AC induction motors are hard to have their speed changed. The load will be about a pound or so and the motor will spin a cage full of beans over a heat source.  I dissasembled a bread machine and the motor is induction which I have heard is not able to be accurately speed controlled.  DC or AC?  I've seen electric drills used to spin the bean cage. What about a treadmill motor?   

Topic by fizzzbang   |  last reply


DC motor regulation

I am planning to build a small gearbox that depends on a steady rpm from a 3V dc motor. I understand that the output rpms will change in correlation to the fluctuation of input power. My question is, if I used a regulator to regulate the input voltage from 5V to 3V, will that keep the motor rpms steady?

Topic by Tman179   |  last reply


High torque solar motor?

I've wanted to do this for ages: build a solar stand for a strawberry planter (or it could be for any other plant) with an extremely low RPM. I'd like it to rotate once every 48 hours so that over time all the sides get equal sun exposure. I'd also like it to be solar powered..... All the motors and kits I find are on hobby sites  and they're tiny little things (plus even the high torque ones  have RPMs above 1). I thought of using a clock mechanism, but there's no way it could handle the weight.... Any ideas where I could find what I need? Thanks!

Question by belsey   |  last reply


Ideal Gear ratio?

Hello i am competing in a design challenge at school. were were each given a 9v 12000 Rpm Motor, the object of the challenge is to build a land vehicle that can go 10m as fast as possible. we will be holding a race on november 3rd to see who has designed the fastest vehicle. anyway my question for the community is using a 12000 rpm electric motor what would be the best gear ratio to use between the motor and the axle to optomise take off speed as well as having a high top speed. (if the gear ratio is to high then the car wont accelerate fast enough to low then the car wont have a fast enough top end) so basicly im looking for that perfect med ground. if anyone here has had much experience with gears and help would be great thanks (PS the vehicle cant be any biger then a vhs case but can be as tall as i want it)

Question by brl60   |  last reply


DC motor

I had a 220v angle grinder. It was burnt. I take the rotor of the grinder out. Its completely fine. Now i make a DC motor using this rotor and magnets(for field current). My question is, how much maximum DC volts this motor can take to get the maximum RPM. Because the motor was 220v AC, Will it run on 220v DC?

Question by Shezi007   |  last reply


Stepper Motor as a 'normal' motor

Hi, I recntly took apart a hard drive and there is a 7200 rpm motor inside. Only problem is that it is a stepper motor and I don't have any equipment to drive stepper motors and buying stuff to do is err... cost prohobititve.  Would connecting a negitive wire to 2 of the terminals and positive(in sort of a crisscross pattern e.g. -+-+) to the other make it run like a regular motor? I just don't want to invest time  to solder it only to have it not work.

Topic by ChickBang   |  last reply


Need a Motor for ASTM testing: 1-5 RPM, ~150 lb in of torque. Any ideas?

I need a motor with low speed and high torque as described above. Thinking about using a 12V power supply but I'm flexible there. I've tried gear motors but I can't find any with the characteristics I need. The application: motor needs to turn a screw that is fixed until the screw fails. After I have the motor I need I'm gonna have to find some way to graph the torque vs. speed curve. Can't spend a fortune but willing to spend up to $100 because it's time critical. Summary: Needed RPM: 1-5 RPM Torque: 150 lb in Cost <=$100 Thank you so much for any suggestions!

Question by nkay3   |  last reply


Air Compressor RPM? Answered

I found an old cast iron 50 + year old 2 stage air compressor and I was wondering what RPM's I should run it at.  My dad says it is running much slower than he remembered and it is going 323 RPM's compared to the original gear ratio that would have run at 269 RPM's.  That should be dramatically faster, so could going too fast decrease performance, or something, or is there a reason the original motor may have slowed down? The RPM's are a complete guess based upon the 1725 RPM motor average.  The only reason I had to change pullies was because the original had FLAT BELTS (awesome) from back when people cared and build stuff right.  Now I have a v-belt on it and the compressor pulley wobbles by like 2 inches and the thing is out of line, but these shouldn't be slowing it down. Basically I need to know what RPM's I should be running the compressor at. P.S.  It can double as a vacuum  pump and it uses old fashion check valves!

Question by jj.inc   |  last reply



What's up with slow rpm motors? Answered

What's the deal with slow rpm motors? I need one for a project and can't seem to find any online. Why not? Am I looking in the wrong place?

Question by noahh   |  last reply


Small motor overheat

On HVAC evap fan motor at 120 Vac no load motor overheat then feedback pulse stop working 5178 pulses / min divided by 4 = 1294.5 rpm shall turn at 1350 + - 20 rpm what make the motor to overheat ? the unit had a power surge when lightning can it be saved ?

Question by jma123   |  last reply


Stepper motor high speed(rpm)?

I need a high speed (rpm) stepper motor but i don't exactly know where and what to look for. I have recently assembled this project for a laser harp : https://www.instructables.com/id/Frameless-Laser-Harp/?ALLSTEPS I have finished everything but the stepper motor parts. The stepper motor I had ( 28BYJ-48 – 5V) had a high torque but was far too slow to split the beams properly. My stepper motor shopping has left me more confused than when i started. Where can I find a quick stepper motor that can run on say 5-24 volts? It seems the stats rarely include speed or rpm. Thank you for any help in the matter.

Question by TheIronHobo   |  last reply


electric motors

I am considering motorizing my bike for my work commute. However I don't have enough knowledge about motor output as in torque / rpms to be able to determine what kind of characteristic I should be looking for. For many of the electric motors I am finding online, it doesn't really say the torque output. Is there a spec such as watts that I can judge a motor by? What specs should I be looking for in a motor that can assist in moving my weight. Or an links to good knowledge sites would be great too. Thanks.

Topic by aeneas shrike   |  last reply


I am building a v-axis wind turbine. I need to know what kind of DCmotor to use for a low RPM DCgenerator. Help me?

The winds in my backyard aren't extremely strong, but I want my design to work and provide a good amount of power if possible.  What kind of DC motor do I need?  Is it easy to create a DC generator from scratch for this type of thing?  Would the ideal motor have a low RPM?  (Because I'm pretty sure my turbine will have a low RPM) Low torque?  Obviously I'm just starting to wrap my head around all of these ideas.  How do I know which motor to get based off the information I am given from the site? Right now I am looking around at www.allelectronics.com , if anyone knows of a better site that would also be appreciated as well. Bottom line: I'm looking for as much power as I might be able to get, but I have low winds, and not a whole lot of money.  I was thinking I might be able to setup the axle to a pulley system with some sort of rubber band going from the axle to the motor, would this work? I know it sounds liek I haven't done my homework, but truly I have, I'm just getting drowned in the options and choices and possibilities at the moment. Thanks so much for you help!  I truly do appreciate your time to help me! Best regards, Aaron

Question by Mr. Retro   |  last reply


Normal motors working as a stepper motor?

Hey folks, I have an arduino(Also l293d motor control) and I was wondering if I could use my normal motor just like a stepper motor by creating a funtion and using "delay" as a mode to control the rpm of the motor

Question by cthaliyath   |  last reply


Very slow rotation (1rotation/hr) electric motor? Answered

I am  looking to build an electronically controlled time lapse pan device for my camera. I want to be able to rotate the camera for a specifically timed time lapse (e.g 90 degrees every 20 minutes of shooting). My problem is finding an electric motor that is slow enough RPM to create this slow of a motion... Right now I would need a motor capable of going down to about 1 rotation in 6 hours... at the very least 1 rotation/hr.  So, do those motors even exist? Right now I am thinking the best solution would be to have a stepper motor, connected to a gearbox (right now that would be the inside of a kitchen timer, somehow), that would allow a very slow rotation of 1 axis. However, as this is a mobile build, power constraints are really an issue. I would like to be able to shoot for 6 hours max continually, and I dont know if that could be done without a very low power motor.... If I did the stepper motor connected to a gearbox, do you think that would affect the linearity of the time lapses? E.g would the stepping motion of the motor create a choppy vid?  I have looked into the kitchen timer timelapse but have yet to find a timer that can hold up my relatively light Panasonic FZ-100 without locking up...

Question by astroboy907   |  last reply


How can I calculate the RPM of a motor running at less than Maximum voltage? Answered

I'm working on a project that needs a certain RPM of motor. I am looking at motors from http://servocity.com/html/3-12v_gear_motors.html. I will be running these motors at ~5v. Is there an equation I can use to calculate this sort of thing?

Question by sblaptopman   |  last reply


What motor should I get? PLEASE HELP?

For science fair,  i need to make a car for a 'king of the hill' type thing I need 2 motors (one for each back wheel) that can get me up the hill relatively quickly. The maximum power source i'm allowed is two nine volt batteries at one time (i can switch out dead ones in between runs) The hill is 40 inches in height and the ramp leading to the top of the hill is eight feet long The motors need to have a driveshaft sticking out about 1-2 inches I'm not allowed to use remote control but i've devised a way so that the car will stop, regardless of what the motor is. A link to a website where i can buy the motors or where i could get them would suffice (please below $15 per motor) Help would be GREATLY appreciated edit: my car will weigh about 1 -1.5 pounds edit: i dont know a whole lot about which motor to get so if someone could (not to sound helpless) pick one for my situation that'd be great

Question by ishmal1103   |  last reply


is the 250 rpm dc motor is good for electric bike??

Is the 8kg-cm and 250 rpm dc motor is good for electric bike??  hi i have a 12v dc geared motor 250 : rpm 8 km-cm : torque is this good for build ebike ??

Question by ShocoM   |  last reply


Stepper Motor Library

Hi! Sorry, I was unable to put library below. So simple and yet so not so simple. How do I get the library in the folder so the program compiles/? Thanks 56Frank library for 28BYJ48 Stepper motor and ULN2003 driver. Here is the source code for our 28BYJ48 stepper motor, ULN2003 driver library, as well as an implementation. Check out the diagram for the wiring. The header file: __________________________________________________________________ #ifndef Stepper_h #define Stepper_h class StepperMotor { public:     StepperMotor(int In1, int In2, int In3, int In4);    // Constructor that will set the inputs     void setStepDuration(int duration);    // Function used to set the step duration in ms     void step(int noOfSteps);    //    for(int sequenceNum = 0;  sequenceNum <= noOfSteps/8; sequenceNum++){         for(int position = 0; ( position < 8 ) && ( position < ( noOfSteps - sequenceNum*8 )); position++){             delay(duration);             for(int inputCount = 0; inputCount < 4; inputCount++){                 digitalWrite(this->inputPins[inputCount], sequence[(int)(3.5 - (3.5*factor) + (factor*position))][inputCount]);             } Arduino         }     } } _______________________________________________________________________ An implementation: _______________________________________________________________________ #include StepperMotor motor(8,9,10,11); void setup(){   Serial.begin(9600);   motor.setStepDuration(1); } void loop(){   motor.step(1000);   delay(2000);   motor.step(-1000);   delay(2000); } Step a certain number of steps. + for one way and - for the other     int duration;    // Step duration in ms     int inputPins[4];    // The input pin numbers }; #endif ___________________________________________________________________ The cpp file: ___________________________________________________________________ #include #include StepperMotor::StepperMotor(int In1, int In2, int In3, int In4){     // Record pin numbers in the inputPins array     this->inputPins[0] = In1;     this->inputPins[1] = In2;     this->inputPins[2] = In3;     this->inputPins[3] = In4;     // Iterate through the inputPins array, setting each one to output mode     for(int inputCount = 0; inputCount < 4; inputCount++){         pinMode(this->inputPins[inputCount], OUTPUT);     }     duration = 50; } void StepperMotor::setStepDuration(int duration){     this->duration = duration; } void StepperMotor::step(int noOfSteps){     /*         The following 2D array represents the sequence that must be         used to acheive rotation. The rows correspond to each step, and         the columns correspond to each input. L     */     bool sequence[][4] = {{LOW, LOW, LOW, HIGH },                           {LOW, LOW, HIGH, HIGH},                           {LOW, LOW, HIGH, LOW },                           {LOW, HIGH, HIGH, LOW},                           {LOW, HIGH, LOW, LOW },                           {HIGH, HIGH, LOW, LOW},                           {HIGH, LOW, LOW, LOW },                           {HIGH, LOW, LOW, HIGH}};                           int factor = abs(noOfSteps) / noOfSteps;    // If noOfSteps is +, factor = 1. If noOfSteps is -, factor = -1     noOfSteps = abs(noOfSteps);    // If noOfSteps was in fact negative, make positive for future operations     /*         The following algorithm runs through the sequence the specified number         of times     */

Topic by 56Frank   |  last reply


Stepper motor voltage too low? Answered

I'm getting started with Stepper motors and I got one on ebay, it's MINEBEA NEMA23 2.5V/1.8 AMPS 1.8DEG/STEP (model# 23LM-C045-01H). I'm a bit confused by it's low voltage. Am I reading it correctly, it's 2.5Volts?  Stepper driver that I have requires at least 8 Volts (it's Arduino with rugged motor driver shield), so is it safe to drive with motor with voltage of 9 or 12 volts?  How would one drive such motor at 2.5VDC?

Question by bratan   |  last reply


What is the power of a battery required to run a motor of 2750 rpm motor?

Pls tell me the power of a battery with which a motor of 2750 rpm motor runs? What exactly will be the weight of that battery?

Question by karthiknune   |  last reply


Adjustment of the speed of a DC motor Answered

I'm working on something that requires a very low speed motor (~.5-4 RPM). I found a motor that runs at 1.5v @ a maximum of 7rpm (5040RPM max with 1428:1 ratio) I need however, something to lower and raise the speed of this motor. I know that people say PWMs for this, but the only one I can find is a 12 volt and has gotten mediocre reviews. Could I use this 12 volt PWM in this system, or could someone point me to a reasonable PWM that would work?

Question by sblaptopman   |  last reply


Unipolar motor driver?

 Dear all  I have this stepper motor and timing for driver(please see photo). Please help me to know time on and off of pulse(frequency) for the  motor rotation 1 turn per minute (1 RPM).Thank you in advance for your time.

Question by lam   |  last reply


General question about controlling car engine ??? Answered

Hi ... I would like to ask, how do call the "thing" that control RPM of your engine ??? What I mean ... there is something - kind of small motor, that controls the RPM. When you start your engine and you don't have any gear it holds the RPM on cca 1000 RPM. But in winter (when the engine is cold) it brings the RPM to 1500 ... and then, when the engine becomes warmer, it decreases the RPM. 1. How do you call the part, that controls these RPM ??? 2. Is there any restriction that says what is the maximum RPM that this "small motor" can provide... like it will not make more then 2000RPM ... or you could set it up up to 7000RPM as well ??? Thank you in advance...

Question by zholy   |  last reply


How do I calculate the RPM of a electric vacuum motor?

I have a Johnson 12amp 120v 60Hz vacuum motor that I scrounged out of an out of commission vacuum cleaner and was curious of its RPM's to see how it would have to be geared to fit my project needs. If anyone out there can help me please speak up.

Question by greensmith7   |  last reply


I have the main motor from a vacuum cleaner what can I do with it? Answered

The motor is very powerful. It runs off of 120 V AC. The cable that plugs into the wall runs electricity straight to the motor. It weighs about 3-4 pounds and has brushes. It has alot of torque. So much so that it will flip in the air to ~1.5 feet when it is first started. I believe it spins at perhaps 2000-3000 rpm though I'm not sure. This motor was the motor that powers suction in the vacuum cleaner. I would love if someone could tell me if I could either use it as an alternator (for pedal power electricity generation) or what I could use it as a motor for?

Question by cdubnbird   |  last reply


Not sure where to find a 60 to 120 rpm AC motor

I'd like to add a small motor to a hand cranked coffee grinder (Hario Skerton Coffee Grinder).  It's conical burr style grinder that produces a consistent particle size (much more so than the mini blender, whirlly style grinder).  I'll expand on why that's important when I build the thing.   My problem is that is takes 10 minutes or so to grind enough coffee for two people. I'd like to put a motor on it.  I tried spinning it with a battery powered drill, but the RPMs were too high.  The burr spun faster than coffee beans could feed.  I'd like a motor in the 60 to 120 rpm range.  I still need to determine the torque required.  Additionally, I'd like to plug this right in to a 110 outlet.  Does anyone have a suggestion on an appliance I could scavenge or the type of motor I should look to buy?   Thanks, Mike

Topic by MikeM50   |  last reply


Low Cost DC motor Controler?

I want to power a 90 Volt, 5amp Perment Brush type DC Gear Motor. The, "Variable speed controller", needs to be able to use 115v AC or 115v DC input power, which is selectable by the operator. I have used a Staco variable tranformer which uses 115v AC input and rectified the output to drive the motor. But also need the 115v DC input option.

Question by Realdann   |  last reply


How to find the rotating shaft rpm?

I have used AC motor of 750 rpm... motor then transmit its power to gear box then to shaft... on shaft rope drum is connected to do the required work i-e lifting or lowering of load

Question by waseemhaider.syed   |  last reply



why machine maximum tortion happened at low rpm?

What caused it happened

Question by ririd   |  last reply


How can I increase/amplify my rpm for a motor? Example: I rotate my wheel 5times it will rotate my motor 100+ times?

Along a generator and trying to figure out what is it that people do that allows them to amplify there rpms so they can rotate there motors faster. Saw some people put series of belts and gears or they use some device that they attach on to the motor "stub" is what I'll call it can't remember right now what it is called but the part that sticks out of the motor that you would put a belt on to spin it. Or hand crank it. Any help guys? Thank you! Have a great day, hope to get a response soon.

Question by onepower   |  last reply


Has anyone Hacked the,&quot; Nsd Power Ball Sm-01 Speedometer ?

Has anyone Hacked the," Nsd Power Ball Sm-01 Speedometer ? The Sm-01 ( the speedometer of Nsd power Ball ) Functions are: a. the count of revolutions ( hundred unit ) b. the current RPM c. the historical highest RPM/ the current highest RPM d. the physical index, 30 sec., 60 sec., 90 sec. The above-mentioned functions work individually. The speedometer can make users understand the use state of PB and provide real figures for reference. It combines the effects of rehabilitation, entertainment, and contest. Can anyone explain how this speedometer works. Is it Optical ? Since the Power Ball has 5 LED's incorporated in the Gyro Ball does this trigger the output ? Or is it magnetic ? When I, place compass next to the Power Ball the compass dial spins like a motor. How can I, use this speedometer to registered the speed or RPM of wheel ? Looking forward to hearing any suggestions, on how I may HACK this Great Speedometer/ TACH . This speedometer can be found on eBay for about $15.00 it's small and compact. It surprises me that no one has Hacked this for other uses !

Question by MagicLanternProductions   |  last reply


which has high rpm and torque, the 3v dc brushed motor or the 12v brushed motor, they are running the same at 6v battery

Is it advisable to use a 12v motor to have high torque and rpm than a 3v motor?they both run at 6v,

Question by antitaengbasuraman   |  last reply


how can i run dc motor with specific criterias as per detail?

1) the motor should move forward for cirtain RPM then STOP when supply is on. 2) the motor should move reverse with exact same RPM then STOP when supply CUT OFF. the supply volage is 230V the motor is 12V DC.

Question by jdixit89   |  last reply