Motors & Drivers Part 8: the ESC — the brain between the battery and a brushless motor
An ESC (electronic speed controller) switches the motor's three coils on and off in turn with MOSFETs, thousands of times a second; the throttle signal sets how fast.
Connect a brushless motor straight to a battery… and nothing spins! 🔋🌀
🔌 A brushless (drone) motor has 3 wires and no brushes, so plain DC can't turn it.
🧠 It needs an ESC (electronic speed controller) in between.
⚡ Inside: 6 tiny switches (MOSFETs). They power the 3 coils a pair at a time — A+B−, A+C−, B+C− … six steps round and round.
🔁 Thousands of times a second, so the magnets on the bell keep chasing the lit coils = it spins!
🤔 So how do you go faster?
🎚️ The throttle signal: a longer pulse (about 1 ms = stop, 2 ms = full) → the ESC sends more power → more RPM. (Many drones now use a digital signal called DShot.)
✅ Pick an ESC rated ABOVE your motor's max current (motor 25 A → a 30 A ESC).
Read the voiceover (transcript)
- Brushless motor straight on a battery?
- Nothing spins! It needs an ESC in between.
- Six tiny switches feed the three coils, a pair at a time.
- Thousands of times a second, so the magnets chase round!
- So how do you go faster?
- A longer throttle pulse!
- Match the ESC to your amps.
- Next: the H-bridge. Follow for Part nine!
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