Les premiers essais (+/- 2A) avec le moteur ne montrent pas de chaleur excessive, mais je ne suis pas encore à l'utilisation maximale de 4 à 5 A. Pour ce qui est de faire un hacheur moi-même, je me demande si cela … Motor Hall - JST-SM: The hall plug is a 5 pin female JST connector using the same pinout standard we adopted since 2008. The motor has a plastic worm gear attached to it and was used as a neck massager. R can be measured as I said above in a comment and which I'll repeat here. There is a dynamic test, too, that can give even better results - do the same as I just said, but instead of locking the rotor, back drive the motor. Of course it wouldn't actually ever get that fast because there would be no EMF left to actually drive it, and no torque left to drive anything else. At 5000 RPM, you'd have 140 V back EMF with 30 V left over to drive the motor at 170 V in, which would take 18 W. That could be quite plausible if the motor is at least fist-sized. PWM DC Motor Speed Control: Power: Sep 21, 2006: 0: 12 Volt Battery Voltage Monitor (kit available) Power: Jun 18, 2015: 1: Battery Low Voltage Beeper: Power: Sep 21, 2006: 0: 12 Volt 15 Amp Low Voltage Disconnect (kit available) Power: Jun 18, 2015: 0: PWM Motor Speed Controller / DC Light Dimmer: Power: Jul 12, 2001: 0: PWM Motor… If you solve for \$i = \frac{V}{R}\$, you can find the current when the rotor is locked at different voltages. If possible, lock the rotor and then apply a small current to the terminals. sur la carcasse. If you think it might be intended to run from rectified 120 V AC, then let's see what 170 V does, since that's what you'd get if there is a capacitor after the rectifier. Perhaps, its buried inside. Therefore on 120V it should do about 4300rpm. There's no name plate and there's a number but it's meaningless. That is a lot for a 'small' motor, so I suspect that one of your measurements is out by a factor of 10. FYI, the motor diameter is about 2 inches wide and the height of the motor is about 4 inches. There's no transformer so I guess it's probably operating at full 120V. I went back and read the resistance, but this time I got around 39 ohms. at 1000rpm on a single cylinder 2 stroke, sparks every 16 seconds, which is already faster than the astable output making the 555 circuit useless , isnt the scr and tip122 just going to stay on because the r/c timing for the 555 never going to discharge fast enough to go low, run the 555 separately in astable just fot the charge circuit … Repeat several times and average. Repeat several times and average. 10A. I want to build a speed controller for a 90 V … I'm able to figure out that the motor is a DC motor because it has two wires coming out of it and there's a rectifier on the speed controller. 50 RPM would be sufficient. The motor resistance is 39 ohms (was reading 50 before). By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy, 2021 Stack Exchange, Inc. user contributions under cc by-sa. Here's a photo of the motor and a snap shot of the circuit: It's mostly about how much power the motor can safely dissipate without getting too hot. (max 2 MiB). The controller is a basic triac/diac speed control with a rectifier at the end. Speed/Thermistor Pass … The board appears to have a triac and perhaps a diac or some diode. 50 RPM would be sufficient speed at which to back drive the rotor. A secondary issue is you don't want the motor to over-spin, but usually it's pretty obvious when it gets that far. There's also a bunch of resistors and capacitors which is probably uses for PWM. That allows for the first pass guess as to how many Watts it can dissipate. And from that current, \$i\$, you can solve for the locked rotor torque at different voltages: \$T_{lr} = K_t*i = K_t*\frac{V}{R}\$. There is a dynamic test, too, that can give even better results - do the same as I just said, but instead of locking the rotor, back drive the motor. A simple model for a DC motor is \$V= R*i + e\$, where \$V\$ is the terminal voltage, \$R\$ is the motor resistance, and \$e\$ is the back-emf voltage. I also discovered that the voltage of this motor is 90V DC. The motor resistance is 39 ohms (was reading 50 before). If possible, lock the rotor and then apply a small current to the terminals. Let's look at it another way. I applied 12V to it and it was reading well under an 1 Amp. I can see what looks like a brush holder, in the vent at the mount end of the motor. DC Motors,DC Motors Base Mount,DC Motors Face Mount,DC Fan Motors,Special Purpose DC Motors,Motor Speed Controllers ... 1/3 HP 90 Volt DC 1800 RPM Motor 56C WWE WPMDC13-18-90V-56CB Item Number: 10-2575 4 ... 90/180 Volt DC Non-Rev PMDC Motor Controller WWE WDCCONT Item Number: 11-3304 7 In Stock. the 4.7uf 400v capacitor is overheating in the 1.2 hp.90v engine. You can also provide a link from the web. If you assume \$i=0\$ when there is no load, that equation becomes \$V=e\$, which becomes \$V= K_b* \omega\$, which becomes \$\omega = \frac{V}{K_b}\$. Your measurements give us some idea, but it would be additionally helpful to know the physical size of this motor. Most motors can do at least 3600 RPM (60 Hz), so let's see how that works out. You can also determine the maximum speed of the motor at different voltages using \$V= R*i + e\$. As somebody else mentioned, the torque constant of a motor is equivalent to the back-emf constant, so \$K_t = 0.268 \frac{Nm}{A}\$. Please refresh the page and try again! It's basically a set of electromagnets that interact with a set of permanent magnets and are mechanically switched at the appropriate times to keep it running in the same direction. I want to find out what is the maximum voltage range for the motor, but it is proving difficult. Depending on how critical it is for the motor to work after testing and what equipment you have, you might slowly increase the voltage into it while keeping an eye on temperature, speed, and current. Quick View. A motor in idle or at low speed cannot charge the battery sufficiently. For the back EMF to be 170 V would require 6000 RPM (100 Hz). There was an error updating your shopping cart! ... the engine will work with 1.4hp. At that speed, the back EMF would be 101 V according to your measurements. D&D Motor Systems is the premier go kart electric motor manufacturer in the U.S. for electric go karts.Our electric go kart motors offer higher performance than the pancake motors that are out there. That would be the absolute maximum speed. 10A 4000RPM. The motor has a plastic worm gear attached to it and was used as a neck massager. Resistance can vary on a DC motor due to brush contact. ©Copyright 2021 Surplus Center, All Rights Reserved. Check my updated question, I've included a photo of the circuit and the motor. At 570 RPM (9.5 Hz) you got 16 V out. How much do you get? 1/2 HP 12 Volt DC … I don't, however, see the brushes. The best way to measure resistance is to take several measurements and average. Take A Sneak Peak At The Movies Coming Out This Week (8/12) New Movie Releases This Weekend: February 12th – February 14th Is there a chart or formula for the voltage vs speed and or voltage vs torque for a DC motor? ... connection cables and took a reading on 200AH battery terminals which was 13.17 V and after one hour readings was 12.90V (note there was no load on the battery, as all the cables were removed) after one more hour reading was 12.46V and after 28 hours … FYI, the motor diameter is about 2 inches wide and the height of the motor is about 4 inches. I chucked the motor on my drill press and spun the shaft at 570RPM or 59.69 radians/sec and got 16V output. Thanks. Does the massager have a label or nameplate, and if so what does it say (model number, Amps, Watts etc.)? Measure voltage and current and calculate R = V/I. The motor looks awefully similar to my motor. Here is a typical small permanent magnet motor designed for 120VDC:-, Click here to upload your image How do I find the voltage range for an unknown DC motor. Measure voltage and current and calculate R = V/I. Resistance can vary on a DC motor due to brush contact. Thanks a lot. Is there a chart or formula for the voltage vs speed and or voltage vs torque for a DC motor? Qty: $264.55. Motor Phase - MT60: The 3 motor phases are terminated with a male MT60 bullet connector.This compact plug supports high phase amperages in a very small connector size. You may also include a mechanical load of some kind and measure torque, like a dynamometer. https://electronics.stackexchange.com/questions/132720/how-do-i-find-the-voltage-range-for-an-unknown-dc-motor/132725#132725. 1/3.73 = 0.268N-m/A or 38oz-in/A. 170 V - 101 V = 69 V left over to drive the motor at 3600 RPM. That would deliver 95 W to the motor, which is a lot unless it's at least maybe 6 inches across. Assuming that it is a permanent magnet DC motor (and not a synchronous, induction, or 'universal' motor) your generator test indicates that the Kv (velocity constant) is 3.73rad/s/V or 36rpm/Volt. Here's a simple PWM based motor speed controller circuit which can be used for controlling a treadmill speed right from zero to maximum. At locked rotor, you know that \$V = R*i\$ because \$e=0\$. You already have Kv and Rm, so to 'complete the picture' you just need to measure Io - preferably with better precision than merely "well under 1 Amp". Please see my updated answer along with a photo. Hook the motor across a 12V car battery and measure the current draw (multimeter on 10~20A range). To characterize a DC motor you need to find its Kv, Rm, and Io (no-load current). I think you're better off finding the spec sheet or doing your own experiments. That's not out of line for a DC motor, not knowing anything else about it. For a given strength, you can make a high-current, low-voltage electromagnet or a low-current, high-voltage electromagnet. You've already found \$K_b\$. For a PMDC motor, Kt (torque constant) is the inverse of Kv. I have a small unmarked motor with a burned out speed controller board. Typically you this test would be done at ~25% rated current. With a resistance of 50Ω the stall current would be 120/50 = 2.4A, so stall torque should be about 0.268*2.4 = 0.643N-m or 91oz-in.