trilerian

iTrader: (51)

I asked a question similar to this a few years ago. The answer was it had to do with the power output of the motor. It stays the same no matter the input voltage.

Edit: To expand further, if the power is the same for 3.4v and for 7.2v and power = torque x rpm, but the rpm drops, then torque needs to increase. Increasing torque will increase current. But the analysers are measuring unloaded so torque should be near zero. Maybe your bearings are bad?

mrreet2001

iTrader: (9)

I don't know why, but from 1s experience Trinity RevTechs do not like the same timings that work fine on 2s.

jasburrito

iTrader: (3)

On 1s it's harder for the high strength rotor to spin. So it draws more amps. 4amp sweet spot vs 6amps 2s kinda normal rotors. your in the middle at 5amps. Bigger round rotors also increase timing. Smaller diameter rotors decrease timing!!! It changes the timing about 20 degree swing. They hit different on the sensors. Big strong rotors like low timing. Smaller rotors like high timing and boost. Buy like 6 way different rotors. Put them in all your motors and test.
8⁸

PDR

iTrader: (31)

Back EMF will increase as the RPM increases - this will increase impedance of the motor. I think what you're seeing is that at 3.4V, it has a lower impedance, but I wouldn't have expected it to be such a big difference. Interesting observation!

gigaplex

iTrader: (2)

I can't see how power would possibly stay the same with reduced voltage like this. Input power = voltage x current. No way for mechanical output power to exceed input. My ESC telemetry shows me that under load, current goes up, not down, when increasing voltage with the same motor. There is no power output at no-load peak RPM either, torque is zero.

I doubt the bearings are bad, this motor has only done 2 events and it podiumed both times.

OffRoadJunkie

iTrader: (9)

As we all know, every electrical device has an amp draw. And the less voltage there is the harder that device has to work. Because of that, it draws more amps.

gigaplex

iTrader: (2)

Ohm's law disagrees with you.

DirkW

iTrader: (1)

OffRoadJunkie
It's just not that simple all the time. If you take e.g. a LiPo Charger and the settings you've selected require let's say 240W from the PSU... then yes, if your PSU only delivers 12V than your charger will draw 20A, while at 24V only 10A (assuming the charger can take both input voltages).

So note: this "the fewer the voltage, the higher the current" is only valid for a fixed electrical power. But not all devices have such fixed power. Some will simply produce/draw less overall power, when you cut the voltage down.

If we take a simple resistor of 1 Ohm and supply 10V, you'll get a current of 10A through it. Same resistor with only 5V? No, not 20A but only 5A. So half the voltage equals half the amps here.

So in layman's terms you need the voltage (often compared to water "pressure") to push a certain current (compared to amount of water flowing per second) past a resistor (obstacle). If you don't supply enough pressure, you get less flow.

OffRoadJunkie

iTrader: (9)

I get it. I understand electricity. I am a master MECP tech. It just depends on what you are doing with it. Example, we would run electronics that cruise at 14.4 volts and low amperage. As soon as the voltage drops to 12, the amps shoot up. When I was a forklift tech, many moons ago, I would get a lot of calls to replace fuses because people would use the forklifts with too low of a voltage and it would raise the amperage and pop the fuse.

trilerian

iTrader: (51)

Has anyone figured out the maximum amp draw the Tunaylzer is capable of handling?

Thanks

OffRoadJunkie

iTrader: (9)

I have not looked into it or tried it.

OffRoadJunkie

iTrader: (9)

With LSR Speedway closed, where are you all racing now? Are you all going to the Delta Speedway?

OffRoadJunkie

iTrader: (9)

How do you hook up a printer to this?

Bsthetech

iTrader: (17)

You can’t, yet. Thats why I’m waiting for V2.

OffRoadJunkie

iTrader: (9)

That sucks!

What's the USB port for?