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| my burnt coils |
For
a given torque and speed you'll need the same phase current through
the motor regardless of whether or not you have a low voltage or a
high voltage pack. The high voltage battery would have the potential
to climb a hill at higher speeds if it is not phase current limited
by the controller. And if you use lower gears to get the same slow
speeds and watts there will be more kinetic thrust at less amps.
If
you want to make a given Permanent Magnet motor spin faster, you can
either run it at a higher voltage, or keep the voltage the same and
use a faster motor winding [with fewer turns]. The former approach
will have your input electrical power at a higher voltage and lower
current, while the latter would be at a lower voltage and higher
current, but the total power (volts x amps) would be the same, as
would the motor efficiency, heating, etc. However, the motor
controller and external wiring can get hotter with the fast wind at
lower voltage and higher current, unless you appropriately increase
the wire gauge and mosfet resistance.
For
a given torque and speed you'll need the same phase current through
the motor regardless of whether or not you have a low voltage or a
high voltage pack. The high voltage battery would have the potential
to climb a hill at higher speeds if it is not phase current limited
by the controller. And if you use lower gears to get the same slow
speeds and watts there will be more kinetic thrust at less amps.
If
you want to make a given Permanent Magnet motor spin faster, you can
either run it at a higher voltage, or keep the voltage the same and
use a faster motor winding [with fewer turns]. The former approach
will have your input electrical power at a higher voltage and lower
current, while the latter would be at a lower voltage and higher
current, but the total power (volts x amps) would be the same, as
would the motor efficiency, heating, etc. However, the motor
controller and external wiring can get hotter with the fast wind at
lower voltage and higher current, unless you appropriately increase
the wire gauge and mosfet resistance.
You really need a controller or CycleAnalyst that shows phase amps and voltage.
[The
Phase wires are the three wires that the controller sends the power
to the motor's multiple sets of magnets to make it turn.]
The
amp current delivered to your motor will be greater than the battery
current at gravity forced low speeds, at higher speeds of flat land
cruising the motor current will equal the battery current. The
controller acts as a power converter and produces more output current
at low speeds. This output motor current can be several times the
battery current at very low hill climbing speeds where the motor's
high drain voltage is low. Installing
a digital thermometer is about all you can do to keep the motor
from burning out, because no one knows how to install a tachometer in
an electric motor. Unless it is some kind of high tech device?
Sometimes
a controller will feed power to the motor even though it is not
spinning. The CA only shows the battery current. [Ask for one that
shows phase amps with a tachometer]. The motor voltage is directly
proportional to the RPM it is spinning at. So if your battery voltage
is 60V, and the motor is 5RPM/V, it will spin at 300RPM. If that same
5RPM/V motor is spinning at 150 RPM, the motor voltage is 30V.
The
only way to read phase amps would be with a magnetometer with
remote readout. Use a Field Oriented "FOC" controller.
[The
Phase wires are the three wires that the controller sends the power
to the motor's multiple sets of magnets to make it turn.]
The
amp current delivered to your motor will be greater than the battery
current at gravity forced low speeds, at higher speeds of flat land
cruising the motor current will equal the battery current. The
controller acts as a power converter and produces more output current
at low speeds. This output motor current can be several times the
battery current at very low hill climbing speeds where the motor's
high drain voltage is low. Installing
a digital thermometer is about all you can do to keep the motor
from burning out, because no one knows how to install a tachometer in
an electric motor. Unless it is some kind of high tech device?
Sometimes
a controller will feed power to the motor even though it is not
spinning. The CA only shows the battery current. [Ask for one that
shows phase amps with a tachometer]. The motor voltage is directly
proportional to the RPM it is spinning at. So if your battery voltage
is 60V, and the motor is 5RPM/V, it will spin at 300RPM. If that same
5RPM/V motor is spinning at 150 RPM, the motor voltage is 30V.
The only way to read phase amps would be with a magnetometer with remote readout. Use a Field Oriented "FOC" controller.
Phaserunner and Baserunner controllers have heat protection
emergency turnoff. Also using Stator-aid in a direct drive HUB motor
will help it stay cool [but not with a geared motor because of the
higher RPMs of the stator [this applies to mid-drive motors in the
proper gear also]. If you use a higher voltage just to run the bike
faster without watching the amps, it can result in coil burn. I
intend to use a 72v battery pack with lower gears just to keep the
motor cooler.
I think I am going to have to drill vent holes
in my mid-drive motor and use a fan blowing down a 1” tube to keep
out the road crud in wet weather.
Instead of one large motor
two smaller ones would be the best for a heavy duty cycle truck.
Although it will require two controllers.
Phaserunner and Baserunner controllers have heat protection emergency turnoff. Also using Stator-aid in a direct drive HUB motor will help it stay cool [but not with a geared motor because of the higher RPMs of the stator [this applies to mid-drive motors in the proper gear also]. If you use a higher voltage just to run the bike faster without watching the amps, it can result in coil burn. I intend to use a 72v battery pack with lower gears just to keep the motor cooler.
I think I am going to have to drill vent holes in my mid-drive motor and use a fan blowing down a 1” tube to keep out the road crud in wet weather.
Instead of one large motor two smaller ones would be the best for a heavy duty cycle truck. Although it will require two controllers.
Every
thing you need to know about hub
motors:
https://www.youtube.com/watch?v=c96n0Ma2rLYhttp://www.ebikes.ca/learn/power-ratings.html
Field Weakening, what is it?
Best new controllers:
http://www.cloudelectric.com/Alltrax-Controllers-s/14286.htm
Best new controllers:
 |
| https://kellycontroller.com/shop/kls-s/ |
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