More about 775 DC motors. Do they work as a generator? How strong are they?
ฝัง
- เผยแพร่เมื่อ 25 ต.ค. 2017
- In a previous video I carried out some tests with a 775 DC motor to show you that the specifications provided on Banggood website couldn’t be correct. Actually the results we got are way out of the specifications. Since then I’ve received some comments about the way the tests were performed and also some requests.
In this video I answer some of those questions and we have a look at what I’ve been doing to get a better understanding of the performance of those motors.
The previous video:
• 775 DC Motor from Bang...
775 DC motor:
www.banggood.com/775-Gear-Mot...
Power meter:
www.banggood.com/50A-DC-Digit...
www.banggood.com/0_56-Blue-Re...
Clamp multimeter:
www.banggood.com/UNI-T-UT210E...
DPS5015 Power Supply:
www.banggood.com/RIDEN-DP50V1... - วิทยาศาสตร์และเทคโนโลยี
just noting, that many, many companies make a 775-sized motor with various output. Johnson Controls here in US are spec on for what you might need in this case size: high rpm or more torque depending on the internals. China motors are moved from warehouse to warehouse, often combined with shipments from other factories, put in bins, reboxed, etc.
if you need 2 matched motors it's best to buy 5 and compare the 2 closest to spec. and then you'll have 3 for other things
Definitely... I can see this picture in my mind.
The best review I have seen of these motors. Very thoroughly and well done!
DoodleFox thank you for watching and commenting!
wrDoodleFox mp56
👍👍🌏
This is one of the best tutorials videos I have ever watched on TH-cam. Thank you very much.
Thank you for your comment. Really appreciate it.
This is what i was hoping to find. More info on 775 motors. Thanks
Excelent video and tutorial about the 775 motors. Thanks for share and greatings from Spain
Thanks for your comment. Really appreciate it.
Thank you so much for the video! Very informative! :)
Thanks for your comment. Really appreciate it.
so at the righty rpm you can get a decent amount of power out of them to be use as mini generators? thank you for your helpful information.
Mabuchi offers their motors with different wind specs. You can have several motors that look identical but have differing winds giving varied outputs at the same voltages. I believe magnet strengths play a part as well. For a good generator, you need a high-turn armature. I have an old Mabuchi 775VB that was out of office equipment. I got alot of voltage from that one!
Hi Steve. Yes, that's the point... some people say for example "one guy made a skateboard with one 775 dc motor and it was strong enough to push it". I say "which one?". Because it is possible to get those motors with a wide range of specifications.
I had a look at Mabuchi website. Looks like they have 775 dc motors rated at 18V (nominal voltage) and really high speed (between 18k and 21krpm). I din't know the company though... i always get those motors from china (Banggood, Aliexpress or eBay).
Btw, thank you for your comment. ;)
My guess is that '775' is just a generic housing size for 12V DC motors and it's wound to customer specifications. Chinese vendors like Ali or Banggood will probably just purchase line rejects or overstock units that are out of customer spec, that's why the specifications of them vary wildly.
Hello,
Interesting video, where did you get the laser beam device? You have a receiver and an emitter? From the video it seems that both are emitters. I understand that the signal is received by the lab scope in the end. But how the laser pairs are working?
Hi, "gearstill". Thanks for you comment.
The laser beam I got from banggood. It uses 18650 battery.
Here is the link with NO battery and charger: www.banggood.com/G301-Adjustable-Focus-532nm-5mw-Green-Light-Laser-Pointer-p-942216.html?p=JM09079991593201704F
And here WITH battery and charger: www.banggood.com/Burning-Laser-301-Green-Laser-Pointer-High-Power-Laser-Suit-5mw-p-948202.html?p=JM09079991593201704F
Note: You must be really careful when working with those lasers. They are quite strong and can cause some serious damage!
The receiver is an ordinary LED. The scope is hooked up to the the leads of the LED. Watch this video where I explain how to do that: th-cam.com/video/2gzRN6KS_p8/w-d-xo.html
If you don't have an oscilloscope you can use an Arduino and read the speed on the serial monitor or on a LCD Display. The code is quite simple and if you have any problem to get it done just shoot me a message.
It is very ingenious indeed. I looked on the specifications of the laser beam, and it seems it is quite powerful. I wander if we could use a photo-voltaic cell/diode instead of the LED, and may be we will not need such a powerful laser?
Regarding the measurement of the torque, even if you use wood, because of the rotation of the rotor, the pressure will not remain the same, because the contact will lose gradually, but rapidly. Maybe just metal on metal, or something like bicycle disc brake, will be more appropriate. A good conductor like copper is preferred, so that we minimize the change of its friction proprieties because of heat.
Hi. Really appreciate your comment. That's exactly my challenge now. Even with wood the the pressure is not remaining the same. So I put all the gauges at a small distance from each other and I was recording the measurements in order to insert the data in a excel spreadsheet afterwards. Than I was thinking to connect everything to a Raspberry Pi, read all the measurements at the same time and export them to a file. At the end I could plot everything. I guess your suggestion is better though... I am gonna try to figure out a better way to do that with metal or bicycle disc brake. Thanks a lot.
About the leaser bean... yes... If you have a less powerful laser you can use a photo-voltaic cell or photoresistor. I had this laser lying around (I got it from Banggood sometime ago for another project) so I used it.
Another option is "Hall effect sensor tachometer". I've also posted a video about that: th-cam.com/video/K0r3FTa_ojc/w-d-xo.html&t
Cheers
Appreciate your experiment
Where did you get the motor coupler?
Do i have to always place it (the motor) horizontally? Can i use it vertically? Thanks and great video!
Great lesson.
Thank you very much sir. This video is very helpful and informative.
iRon322 you're welcome!
thank you for posting this info.
You're welcome. ;)
thank you for this excellent and useful video. well done
Claudio, you’re welcome. Thank you for watching and commenting!
Claudio Fonta channel pop-opera
Am use 12v dc motor for power generator. How ouput volatge and watts it produce.can u pls explain about this
Thanks much Robledo! Well done video. It is too bad you really can't tell which of so many 775 motors you will receive from these Chinese suppliers. So many incorrect specs. It was a very well thought out way of trying to rate the torque specs that you came up with. The 775 seems a poor generator as I had asked about. I think you will do well with that new motor which looks like a scooter or bicycle motor. I have seen several such motors on eBay and think one of them may work well as a generator. Many blessings!
Hi, revscott. You're very welcome.
Yes, I think this motor will push my car very well. You're right it is designed for e-bikes/scooters... I got tired of trying to figure out the best setup using 775 DC motors. Recently I "fried" my 18650 battery pack (4S8P)... so I decided to get this BEAST!!! Got 2 of them :D.
I'm wondering if it will be fast enough. Have to test it out.
About a DC motor as a generator... well, you know that, even though it is easy to get a DC motor working as a generator, you will never get the same amount of energy you use to run the first motor (and, yes, electrical motors need to be electrically powered to delivery reasonable amount of energy). But they heat up, they produce sound, magnetic field... all kinds of energy you will "lose". Just a fraction of this is converted in "usable" energy. If you want to convert mechanical in electrical energy you should use a dynamo instead... Anyway, I guess brushless motors are better generators. However, you might need to rectify the output.
BTW, I might be wrong. So, let me know if you get further progress in this subject.
Hi, to correctly measure the torque you would need to accurately factor in the friction between wood and shaft which is pretty near impossible. I guess thats why proper testing equipment is expensive and maybe uses the principle of magnetic emf back force . thanks for the earlier part of this exposing the limitations of choosing a motor (775) based on physical size alone
what is the correct power supply 12v/220v to connect 160psi 12V Self-priming Water Pump 8L/min 100W ???
Thank sir very informative and helpful for me.
Thanks for your comment. Really appreciate it.
Are you preparing with new e.motor
to make personal go-cart ?
What battery do you use to power the motor
Which motor should I bought to get 12volts and 100amps.
What is the backing song? I cannot find it with shazam.
How much watt need dc 775 24v motors?
I mean i have 24v-3amps-35w power adaptor but but when i load my motor is not working properly..☹️.does 65w or 95w adapter working please ans.....?
When you test the motor as generator, the drive motor recives 12 volt DC in....BUT is'nt the output from the second motor AC, meaning that you get around 8 volt AC out?
If you rectify those 8 volt output through a diode bridge, and a use a coupling capacitor the hold the voltage, the resulting DC voltage will be square root 2 times the 8 volt, resulting in the 12 volt you put in in the first motor.
In other words 12 volt DC in can not be compared directly with the 8 volt AC out, the AC out needs to be converted back to DC before it can be compared to the input DC voltage?
Interesting. Actually, for your RC car, I'd recommend a brushless motor. They're quiet, fast, and very small (I have a 210 W brushless that's about half the size of the 775 motors). The only inconvenience is that you need an ESC, but it's easy to control with an MCU, like Arduino. Just send pulses between 1 and 2 ms and it will control the speed of the motor.
Hi GRBTutorials. Thank you for commenting. I appreciate it.
Yes, i do know it would be an option to use a brushless motor. When i made this RC car i decided to use components i had on hands though. That's why i ended up using the 775 motor. After that i bought the big (scooter) motor (i show in the end of this video) for another project... I havent tried yet because it is winter in Switzerland and it's pretty bad weather to do anything outdoor... i will try that in a couple of weeks and if it doesnt work well i will buy a brushless motor. Lets see. Any of those options i will record a video and post in this channel. Catch you soon ;)
Give. Me. The Price. Of. This. Motor
've read somewhere if you remove the outer shield (something to do with magnets power) the motor will have more speed and less torque
Where the review of the lasta black bifg motor??? Thanks for share, i join-
Tanks. Vert helpful
You're welcome.
which was second bigone motor can you tell name of it plz
The motors used in the comparison are all 775 DC motors (from Banggood). The motor I showed at the end of the video is this one: www.banggood.com/24V-17A-300W-2750RPM-Brushed-Electric-Motor-For-E-Bike-Scooter-p-1190267.html?p=JM09079991593201704F
hello, very nice video. Please, could you measure the rpm at 12 volt and 24 volt of the 4'' motor( 0,25 A no load)? thanks very much
Hi TheLollodue. Thank you for the compliment. The answer is: at 12V - 3600rpm and 24V - 7200rpm. Btw, I recorded a video to show you how I measured it. Have a look: th-cam.com/video/_805tZNyqos/w-d-xo.html&t
Where can I buy that motor DC 775 in the Philippines?thank you..
Lazada 418php + 97 delivery fee
Nice video... Sir.. I want to make a powerfull bike washing pump but I do not understand which motor will be best..pls.. Could you tell me the motor name & Rpm?
24v bldc motor 350watts is powerful for ebike
very nice job.
Thank you very much, Kilen.
Can it use as generator to charge 12v battery?
Thanks again
I can see sparking during a load test of 775 motor!
Its normal
In previous video circle with holes is mounted, motor need more power ... it is logic ...
Awesome
NICE LAB
I'm also wanted to buy that motor
That is my1016 motor?
some very late info. at :40, at lower, the motors appear to be two different finishes. is this an Indicator of differing specs? at 3:06, keep going, and you are gonna DEFORM the case of the motor. googletranslate
How much in bangladesh?
Interesting
Did you know there is no follow up of this video.
Can I mack ebike with this motor?
Devanshu gamer you can make a bike with very small wheels. If you use big wheels you not gonna have torque power. You cannot go on hills. Try to make a trike scooter with rear wheels each one with one motor 775.
Thanks for info
👍👍
Quem vende esses Motores e preços?
Banggood or eBay. Tem o link na descrição.
wow just a tiny watt we need to run the motor to at least 4000rpm or 80mph or 120km/hours? its seem we need to wait tornado to run the wind generator and the tornado need to run 24 hours for that tiny watts cycle energy to charge the battery of 16000mah, and the price's home gone by tornado
why are these motors so ubiquitous?
What a DC batter run this motor
So many views but so low subs
From this we could conclude that there are many snobbish and greedy people out there who wouldnt give subs to people that had shared such detailed information without asking anything in return except for subscription.... Reality does hurt doesnt it?
some more info. without a complete rebuild, the internal structure of a pm/dc motor does Not result is Good performance as a generator/altern. the fact that the output from a brushed pm motor is DC is a clear indicator that the energy conversion efficiency is Very low. why is this true. the structure and connections at the commutator result in 'mechanical', less-than half-wave rectification. googletranslate.
My mother was run slow at 12v and 6amp
My motor not mother
See your comment
Kalau beli berapa harganya
No ...i think they use different copper wire cause they dont give a shit on reiability.
Can I make ebike with these motors
No. Not enough torque. And not the right application. It's not designed for that.
Way it is stiling whil running time
775motor how it's work? .it's too danger🤪🤪😱😱
ভাই এই মটর ক
Hagu
hey cheap double shaft motor everybody is looking for them. anybody got an indigogo. 19.99 or i call you name 15. and i call you smart. put msrp on the labels for the motors.
so banggood its a scam than....
well nothing new since its chinise,and its well known and ignored by the most part og people buying on banggod...
at this point prefer very much make one myself since DC motor such as 775 aren't hard to put together
and you can find the parts anywhere from the outside body to the rotor..
as i said in many other videos,ANY AC/DC electric motor can generate electricity.
Each motor is different from others,that mean that each specific motor has its specific way to be used as generator.
Example induction motor cannot generate electricity by itself!
BUT you can make induction motor generate electricity.
2 Specific ways to make generate electricity an induction motor:
1 Apply even 12V AC to one coil and extract electricity to the other coil as long as the input electricity its AC.
2 Magnetize the rotor,since the rotor its composed mainly by metal sheets round shaped and alluminium that keeps tight together all the metal round sheets.how to do that?
Well ask yourselves how a mechanic magnetize its screwdrivers: a car battery few inch to feet length of 8-10 AWG wire wrapped tightly around the metal side of the screwdriver..
or an even safer way use a dc power supply at low voltage 1.5V high amps between 8 to 10 amps for 10-15 seconds.
Quoting someone: Ignorance is a Blessing for Fools and Idiots.
If anybody would like to prove me wrong well..the only way you can do that its put to testing what i just said MEANING BUILD A GENERATOR WITH AN INDUCTION MOTOR EITHER SUPPLYING ELECTRICITY TO ONE COIL OR MAGNETIZE THE ROTOR...
OTHERWISE you do better shut the fuck up..
coz people that talk talk talks prove nothing!!!
many of those that were saying cars cannot run with electricity or hydrogen HAVE BEEN TO BE PROVED HIGHLY WRONG!The first to prove that cars could run without gasoline was Nikola Tesla built in 1892 and registered its electric car on NYC Patent Office in 1902...since america its built in bunch of FAT lies to benefit only scumbags like JP Morgan, well..................
made in China... *shrugs
My experience with bangood was ... shit, shit quality products. Id advise to stay away from bangood.
For a constant load on the generator, it sounded like the motor's RPM dropped and gained randomly. That is a indication of a bad motor or bad power supply, and i would out my bet on a bad motor.