ok I’ll get the quote for u since reading the link seems to much. I keep bringing it up because it seemingly goes against BASIC electricity formulas.
I don’t know how it works. That’s what I’m asking. But I will link it word for word for u
Ren: "Do you know transformers?
You can transform 220V, 1A to 22V, 10A, right?
The VESC is doing the same, it is transforming 50V, 25A into 20.8V, 60A for your motor"
I rest. I quoted for u. Said to specifically convert voltage to amps like a transformer. Answer to that. I do read links if u find one explaining how it works. I’m here asking not telling more than that.
@Hummie Volts and amps are two sides of the same coin or two characteristics that can’t exist without each other. You can’t only have one side without the other. And one “side” does not get converted to the other “side”. I like the water analogy to visualize these electrical characteristics where the water pressure (electrical potential) is volts, and the size/diameter of the hose determines how much water (amps) can flow through that hose. This illustrates how pressure and flow are two totally different characteristics of the system, and can’t get “converted” from one to the other. Here are some examples of how they relate to each other.
Garden hose (~6s) = low pressure (volts), low flow (amps) Fire hose (~12s) = high pressure (volts), high flow (amps) Pressure washer (~24s?) = very high pressure (volts), low flow (amps)
I like to go one step further and imagine the hose diameter is flexible, like a ballon, to simulate a change in Amps, and the amount of Load on the system determines how large that hose or balloon diameter can get. At some point it will stretch too much and pop from too much Load drawing too much Power (pressure x flow) from the system. Conversely, at a small load, the hose will shrink to a very small size, and only require a small amount of flow at that pressure.
Here’s a link to hopefully describe it much better than I can.
https://learn.sparkfun.com/tutorials/voltage-current-resistance-and-ohms-law/voltage
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No more water analogies please:laughing: I know ohm’s law. This is not basic electricity and it’s been said by Vedder and Ren that the vesc converts/transforms voltage to amps for the motor. Thems facts. Anyone who can explain that more in detail id like to read from.
Oh my god. Where is your VEDDER’S HOLY GRAIL QUOTE??
jaroslavnovotny wrote: “This is wrong. With more RPM the current the motor draws decreases, because torque decreases as rpm rises.”
“You are talking about motors that are not relevant to the VESC.” Ren
Vedder:
What causes heat in both the motor and VESC is the motor current. Neither the motor nor the VESC care about the battery current, only the battery does. Also, the battery current can never be higher than the motor current. So when you set the current limits you should set the motor current to a suitable value for the motor and VESC. For setting the battery current you only have to look at the battery.
On low speed the motor current is much higher than the battery current, and on full speed they are the same. This means that if you have very high top speed the VESC will get warm on low power levels when running on low speed. The faster you go, the less heat the VESC generates per power output because the motor current is what causes heat and the battery current is what defines power.
Regarding the motor getting hot under a given load, this has nothing to do with the kv, as I wrote a bit about here: http://vedder.se/2014/10/chosing-the-ri … kateboard/ so if you have a given motor with different kv choises and the same copper fill, all of them will generate exactly the same amount of heat going up a given hill at a given speed. Changing to a higher kv value and running on lower voltage and higher current does not change the heat generation of the motor one bit. The motor only cares about the torque it has to provide, regardless of the kv/current combination.
“At low speed the motor current is much more than the battery current.”
Are we going to argue with that from the designers mouth
There a battery amp limit and a motor amp limit you set on the vesc
Ok tell vedder. I’m done. Ur arguing with what he’s said now and I’ve quoted it. Nothing more for me to do.
Still didn’t seen any quote on volts converting to amps, just read about motor pulling out more amps at low rpm because it needs more torque.
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“Motor current much more than battery current”