washing machine motor run on DC

Thread Starter

Haropas

Joined Aug 16, 2019
41
So, generally, I am trying to use a washing machine motor for an e-bike but today I want help with some of my thoughts.
the washing machine motor is a universal motor and that means it can run on AC and on DC. But when I connect the motor on AC I can't control the speed and the torque making the motor practical. for example,I connect a 12 battery to an inverter (220-volt ac output), and when I press the throttle the motor spins at 11000 rpm. If I step down the ac voltage to 100V AC continues going that fast and probably I'll burn the motor. So this is a dead-end for
the project.
But I found out that if I run the motor on DC I can control the speed of the motor just by lowering the voltage on the armature or on the coils. but if I ran the motor on 12 volts DC I have very little torque, if I step up the voltage on 36 more torque and speed, and in 72 volts DC even more but still not enough for my project.

so here my two thoughts.
1) Is it better to use a 12-volt DC battery to connect it to my inverter (that I already have) and then I can make a DIY diode bridge with a capacitor at the end of the motor for creating 300 V DC and run the motor with a simple dimmer? ( I want DC because is the only way to control the speed), but i dont know what losses I'll have and also I am not quite sure about creating the 4 diode circuit correctly.
Or
2) Making a step-up converter I think again with diodes for converting 12 DC (from a battery) to 100 Volts DC or more

but again I don't know if I have losses and if you have a better idea please share it. Also, I want the lighter solution because the project is an e-bike and also a cheap solution because making a 200V battery pack is just funny.
 

MaxHeadRoom

Joined Jul 18, 2013
23,087
A Universal motor is a form of series field motor, They posses very high initial torque, but operate in a run-away condition where RPM is governed by load and windage etc.
Series field motors when used in applications such as Automotive starters, are always under load.
For your application, I would say not a good choice of motor.
Max.
 

Thread Starter

Haropas

Joined Aug 16, 2019
41
A Universal motor is a form of series field motor, They posses very high initial torque, but operate in a run-away condition where RPM is governed by load and windage etc.
Series field motors when used in applications such as Automotive starters, are always under load.
For your application, I would say not a good choice of motor.
Max.
Yes I see. Actually, I know that the motor isn't right for the project but I would like to try every possible solution with the things I ve got (free motor, free inverter, free bike, free pulleys) so I ll combine everything with free imagination and I hope it ll work.
I think I ll go with the inverter and bridge diodes.
 
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