Hobby BLDC ESC snsor connections

[Circlotron]

Looking on ebay for a small electronic speed control for a PMSM with sensors. The motor I want to use it on has 3 sensors, so a ground wire and three others. Many of the sensor ESCs I have looked at seem to only have 3 sensor wires, red, black, white. Is this for a potentiometer connection instead? So how would connect three sensors? Example ESC ->  https://www.ebay.com.au/itm/315093498324?itmmeta=01HVQT2F6ED5QHD9GKQXH79FK0&hash=item495d0939d4:g:bv4AAOSwkz1lojwl&itmprp=enc%3AAQAJAAAA8MSg8sdXiwgJOAvXwOYbBAWlrRL93sAXiw3NYa4fA5r5cQ9Uki4fI6PpcXgkGaTaXxZwj5uWTMyT4YG4L%2BIXsKIFBWkthLR3G2NgAFypSxUn5TL8%2FUWSyV2%2BgSPQ7NWiNrzUvmrIRO5ACU%2ByJZCR9azgFr2GhZAABKm8JAFOXSr%2BHgU95sn5ZL9sHkd2Kpy8e2AwVwa3so5NRX7o8Wtuji21tr7d07GlY9xWfqOHxROQ%2Fp3NhKQr%2BnJQdSthmh94%2B5S6cymCXpwJ65JWNtuyrJJM5f0EwB3Kz9L%2FG0w153NoM5dw7TztgAAYL1xICRo5aA%3D%3D|tkp%3ABk9SR7DzifrdYw

[mtwieg]

Actually I would expect five wires for the sensors, typically they need both GND and a supply voltage. Long ago I took apart some old BLDCs and found some with passive sensors (some had pickup coils, others seemed to have two-terminal magnetic sensors, maybe magnetoresistive?). But I would never expect to find exotic stuff like that in a toy ESC like this...

[langwadt]

I'd expect the red-white-black to be for the RC-servo like pwm signal to control the ESC

[Circlotron]

Actually I would expect five wires for the sensors, typically they need both GND and a supply voltage.

Five wires... oh yeah, of course.
After looking a bit further I found an e-bike controller that should do just what I want. There are heaps of these available at very low prices. I just want to mess around on the bench with a motor that is about the size of a coke can.

https://www.ebay.com.au/itm/404922267506

[mtwieg]

I'd expect the red-white-black to be for the RC-servo like pwm signal to control the ESC

You're right, it does look just like a RC servo pwm cable. But that makes no sense on a BLDC controller (unless it's used to control speed, not position).

Five wires... oh yeah, of course.
After looking a bit further I found an e-bike controller that should do just what I want. There are heaps of these available at very low prices. I just want to mess around on the bench with a motor that is about the size of a coke can.

https://www.ebay.com.au/itm/404922267506

Well that does have five wires for the sensors, at least. e-bike/e-scooter controllers like those are probably a good option, so long as you have decent documentation for them.

[langwadt]

I'd expect the red-white-black to be for the RC-servo like pwm signal to control the ESC

You're right, it does look just like a RC servo pwm cable. But that makes no sense on a BLDC controller (unless it's used to control speed, not position).

plenty of bldc controllers with rc servo pwm interface for controlling speed