Hi all. in recent years, i have been modifying small brushless motors, computer fans,floppy drive spindle motors and a rewound R.C plane motor with neo magnets. I started with using a mini isolation transformer to sense off the same coils being driven, that switches a transistor on and off, to run the motor. Then i added a run capacitor in series with the driven coils and a second mini iso trnsfrmr to switch a second transistor. so T1 switches the driven coils on and the run cap charges up. Then T2 is switched on and discharges the run cap back through the driven coils, but with the current reversed.As the rotor has advanced 90 degrees,this is complimentary to running the motor.Sort of like using little packets of power twice.See attachments.
Here are some multimeter readings, taken with the computer fan in the pics. The power supply is an unregulated multi-voltage plug pack. 100 hz=50 revs/sec=3000 rpm
4 coils driven pulsed dc 4 coils driven psuedo ac
8.8 v 84 ma 72 hz 9.6 v 34 ma 76 hz
10.2 v 97 ma 80 hz 11.2 v 42 ma 89 hz
13.5 v 122 ma 98 hz 14.8 v 59 ma 116 hz
As it stands it's not self starting. Additional electronics need to be developed.Something like using the standard hall effect sensor/circuit in the computer fan to start, then switching to this "conservation mode". Also pulse width modulation is used to efficiently modulate the motor output, in electric cars. Running in C mode, i guess run caps with different values or individual drive coils would need to be switched in and out,possibly with the aid of zero crossing circuitry, for variable throttle control.
Recently i got a bigger computer fan to run nice using it's own hall sensor, as per the last circuit diagram. it runs even better.
So the big question is.... if i use 70 -200 uf low esr run cap capacity for these little motors that consume less than 1 watt in C mode, is it viable to run say a 25 kw motor like this.Do the necessary caps exist, or could batteries be used, or some sort of hybrid storage device. If it can be done,then this approach may double the range of electric vehicles and battery tools and garden equipment,etc.,with further development.
I would appreciate any comments or advice.Any feedback is welcome.
cheers.
lasermouse.
Here are some multimeter readings, taken with the computer fan in the pics. The power supply is an unregulated multi-voltage plug pack. 100 hz=50 revs/sec=3000 rpm
4 coils driven pulsed dc 4 coils driven psuedo ac
8.8 v 84 ma 72 hz 9.6 v 34 ma 76 hz
10.2 v 97 ma 80 hz 11.2 v 42 ma 89 hz
13.5 v 122 ma 98 hz 14.8 v 59 ma 116 hz
As it stands it's not self starting. Additional electronics need to be developed.Something like using the standard hall effect sensor/circuit in the computer fan to start, then switching to this "conservation mode". Also pulse width modulation is used to efficiently modulate the motor output, in electric cars. Running in C mode, i guess run caps with different values or individual drive coils would need to be switched in and out,possibly with the aid of zero crossing circuitry, for variable throttle control.
Recently i got a bigger computer fan to run nice using it's own hall sensor, as per the last circuit diagram. it runs even better.
So the big question is.... if i use 70 -200 uf low esr run cap capacity for these little motors that consume less than 1 watt in C mode, is it viable to run say a 25 kw motor like this.Do the necessary caps exist, or could batteries be used, or some sort of hybrid storage device. If it can be done,then this approach may double the range of electric vehicles and battery tools and garden equipment,etc.,with further development.
I would appreciate any comments or advice.Any feedback is welcome.
cheers.
lasermouse.
Last edited: