Can I connect Phase to dc load somehow?
- Thread starter rg12
- Start date
dustNbone
10 kW
It's basically 3 phase AC power that comes out of the controller, so you need 3 loads, one across each set of 2 phases.
Say your phases are labelled A, B, and C
You need a loads across A-B, B-C, and C-A, they will energize in turn as the phases "rotate".
This might work with a sensorless controller, but for a sensored one you'll need some way to simulate the hall sensor signals that the controller uses to determine when to "rotate". That would be a much more complicated thing to simulate.
Say your phases are labelled A, B, and C
You need a loads across A-B, B-C, and C-A, they will energize in turn as the phases "rotate".
This might work with a sensorless controller, but for a sensored one you'll need some way to simulate the hall sensor signals that the controller uses to determine when to "rotate". That would be a much more complicated thing to simulate.
Alan B
100 GW
You could program an Arduino to generate the hall signal sequence. They can rotate at a constant speed to distribute the power across the three loads.
Another approach I've used is to hook up a very small brushless motor so it will run, then add the 3 giant resistors across the phase wires to increase the load.
Right. If there is no sensor input, you won't get any output. The little motor gets the controller to fire on all phases.
With many controllers, you could simulate a valid hall signal by just connecting one of the hall signal wires to the 5v and you would get output between a pair of phase wires, but if the signal is static, most controllers will time out after a few seconds thinking the motor was stalled.
With many controllers, you could simulate a valid hall signal by just connecting one of the hall signal wires to the 5v and you would get output between a pair of phase wires, but if the signal is static, most controllers will time out after a few seconds thinking the motor was stalled.
FWIW, those little ebike testers may already have a circuit in them to simulate the hall signals, given that they are intended to test a controller. Haven't done a test like that or opened one up to check that though.
Alan B
100 GW
Controller will shut down if motor does not spin, as fechter said. Phases should be connected so relationship between phases and halls is correct. Additional power can be consumed by paralleling equal loads to phases.
Alan B
100 GW
Yes, that's what was suggested several posts back by fechter. You are essentially building a low efficiency motor.
If I order 3 of these:
https://www.aliexpress.com/item/1-5-Inch-Stainless-Steel-Copper-Head-Heating-Tube-220V-9KW-Electric-Heater-Pipr-Water-Boiler/32707082555.html?spm=a2g0s.9042311.0.0.npFyn7
How do I connect the exactly?
I see that it has 3 heating elements which for some reason are shorted at the terminal.
Is that for a 3 phase connection?
It's rated for 9kw at 220v so if I give it about 80V it will be almost 3300w and if connect three of these in series somehow I should get about 10kw at 80v which is 125A and thats about what I'm aiming for.
https://www.aliexpress.com/item/1-5-Inch-Stainless-Steel-Copper-Head-Heating-Tube-220V-9KW-Electric-Heater-Pipr-Water-Boiler/32707082555.html?spm=a2g0s.9042311.0.0.npFyn7
How do I connect the exactly?
I see that it has 3 heating elements which for some reason are shorted at the terminal.
Is that for a 3 phase connection?
It's rated for 9kw at 220v so if I give it about 80V it will be almost 3300w and if connect three of these in series somehow I should get about 10kw at 80v which is 125A and thats about what I'm aiming for.
Alan B
100 GW
Power goes with voltage squared (if the resistance does not change). So if you use 80V which is about 1/3 of 220V you'll get 1/9th the power.
You'll have to get more information from the vendor on how it is wired. Or just tell them what you want and let them tell you how to do it.
You'll have to get more information from the vendor on how it is wired. Or just tell them what you want and let them tell you how to do it.
Alan B said:
I thought that a third of the voltage on x amount of resistance would cause the amps (and wattage) to be a third too, so why 9th if the resistance is the same? I checked this with this calculator:
https://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.html
Alan B
100 GW
Yes,
Power goes as the square of voltage when resistance is fixed: P = E^2 / R
Current is proportional to voltage if resistance is fixed: I = E / R
But Power comes from both voltage and current, thus it is affected by the change in both voltage and current: P = E * I
So if voltage is 1/3 then current is 1/3 and power is 1/9 th.
Power goes as the square of voltage when resistance is fixed: P = E^2 / R
Current is proportional to voltage if resistance is fixed: I = E / R
But Power comes from both voltage and current, thus it is affected by the change in both voltage and current: P = E * I
So if voltage is 1/3 then current is 1/3 and power is 1/9 th.
JanComputerman
10 W
The three load resistors connect between the three phase wires ... One resistor between any two wires will be a load. If the controller does indeed time out detecting a stall condition then yeah three resistor loads would be needed if no stall function is designed into the controller then all that you need do is connect the ONE right hall sensor input to the 5 volt wire (red) on the hall connector to activate an output phase of the controller. (Or is it to ground?) You may see this easier if you connect a 120 volt light bulb between each of the controller outputs so you see them light up as the output phases turn on and off. The old single xmass bulbs work great or a 120 volt low wattage halogen bulb with pin contacts. Otherwise go the motor route but keep in mind that the throttle will control the output power level and the motor will be spinning fast at full throttle. You may also get additional controller FET heating due to high frequency switching of a non-inductive resistor load.
JanComputerman
10 W
If you use a motor you can just connect the hall sensor connector to the motor and turn the motor by hand to activate the phase outputs along with some throttle. As long as the motor is turned it should keep the outputs sequencing on and off as fast as you spin the motor by hand.
Leaving the motor phase wires disconnected from the controller makes it easier to just connect the load resistors to the controller phase wires.
Leaving the motor phase wires disconnected from the controller makes it easier to just connect the load resistors to the controller phase wires.
JanComputerman
10 W
Try them with one per phase and remember that only one is active at a time ...then connect all three in parallel on one phase and you have your maximum load but it will only turn on for the amount of time that your controller allows a stall condition. Turn the motor connected to your hall sensors to activate it keeping in mind that you will be driving only two of the 6 output FETs at a time so they will not have any rest to recover from heating however there will be 4 FETs connected and you have 2 motor positions which will activate different sets of FETs, driving the outputs high low and low high... opposite polarities on the load.
JanComputerman
10 W
If you have done the math right it will not matter but start with one on each phase then try two on one phase and you can always lower the battery voltage which is always a great way to start.
I have a RoboteQ HBL1650 controller 150 amps 50 volt and after using it for years finally connected it to two 6s12ah 15C graphene batteries in Series (12s) for just over 50 volts (max 55) and it works great. Prior to this I only ran it on 36 volts (9s).
I have a RoboteQ HBL1650 controller 150 amps 50 volt and after using it for years finally connected it to two 6s12ah 15C graphene batteries in Series (12s) for just over 50 volts (max 55) and it works great. Prior to this I only ran it on 36 volts (9s).
