120vdc motor question

[manstoblame]

Hey fellow members here i am back again with a dumb question but I lack the the understanding that you here in the BCF have. I need a motor for a pedal assist on my bicycle that I can remove when parked to prevent theft, it has to be small but powerful, so i thought to use a inflatable beds motor but it happens to run on 120 volts dc. Question i'm faced with is if it can be powered off lower voltages and have same rpm? Just asking for a little help

[redwire]

Re: 120vdc motor question

It looks like a brushed DC motor, which will have proportionately lower speed and torque if given lower voltage.

You can look for the motor's datasheet. HV3657-110-GF I could not find data. The motor's speed-torque curve line moves down with less voltage. So half rated voltage, say 60V roughly half the speed and torque. The motor cannot take a lot more current to make up for it, the winding and brushes heat up too much.

I would not use it for an e-bike because speed control is best done with PWM on a brushless motor, you get much greater efficiency and better low speed torque. This is why they are king for drones, e-bikes, electric cars, RC toys etc.

Or rewind the motor to better match your battery pack voltage. 120VDC is a bit much to unplug in the rain, any thief would zapped.

[manstoblame]

Re: 120vdc motor question

Thanks Redwire for your quick response and thorough explanation. looking for a better motor will be my mission and if you have a suggestion its appreciated in advance. Thanks again

[stj]

Re: 120vdc motor question

look at the ones on ali-express
if you have the money - look at the Bafang - it fits in front of the pedals and links there.

[manstoblame]

Re: 120vdc motor question

Thanx STJ will do

[manstoblame]

Re: 120vdc motor question

look at the ones on ali-express
if you have the money - look at the Bafang - it fits in front of the pedals and links there.

Not bad but trying a diy plus I live in an area I would like to be able to plug and play if you know what I mean but again thanks those may help with a concept maybe