I Finally Got My Hall Effect Sensor Motor Running (16AWG Coil)

Hook

I fired up a single 16AWG coil with a 26 gauge trigger strand on just 3 volts and it actually spun the rotor like crazy. Then I gave it 5 volts and the whole thing went full train noise before the coil let the smoke out. This is the raw bench test.

Watch this experiment

I stacked one 16 gauge coil on top of another just to get enough height so the magnet would pass in the right zone. The air gap ended up around a centimeter or two. Nothing fancy, just a transistor, a power supply, and that little coil on top.

What you'll learn

You’ll see real current draw at 3 volts, how fast it accelerates with ceramic bearings, and exactly why I’m thinking about adding a hall sensor next. Plus what happens when you open the coil up with zero extra resistance.

From the bench

I used three 16 gauge coils I already had wound with 280 turns each. One of them has a 26 gauge trigger strand. Right now I’m only running the one coil. The rotor has ceramic bearings so it spins pretty free. I kept the air gap mediocre on purpose—about a centimeter to two centimeters. The hit zone seems to be right around one centimeter away from the coil face.

How it works / what we changed

Started at 3 volts. You can hear it pick up speed right away. Current draw was around 500 to 700 milliamps once it got going. The rattling noise was the rotor so I killed the power quick. Then I tried 5 volts and that’s when it really took off. It sounded like a train. No external resistance at all, just whatever is in the coil itself. That 16 gauge wire with 280 turns around the bobbin handled a lot until it didn’t.

hall sensor

I mentioned in the video that I might hook a hall sensor up to this setup and run the trigger strand to the base of the transistor. The whole thing is a 3-volt system right now, but I think the hall sensor will probably need 5 volts to work reliably. That’s why I tested at 5 volts in the first place.

hall effect

The plan is to replace the current trigger method with a hall effect sensor so the timing stays clean even as speed changes. I didn’t get it wired up in this test but it’s the next logical step since everything else is already running so well at low voltage.

little coil

This is just that little coil on the top. I call it a medium-size coil but it’s still small compared to some of the big multi-coil builds I’ve done. 16 gauge with 280 turns plus the 26 gauge trigger strand hooked to one transistor. It surprised me how much torque it made on 3 volts. Freaking awesome.

Builder checklist

• 16AWG coil, ~280 turns on a bobbin
• 26AWG trigger strand (or hall sensor later)
• Simple transistor driver
• Ceramic bearings on rotor
• Power supply starting at 3 V, max 5 V for testing
• 1–2 cm air gap, aim for 1 cm hit zone
• No added resistance in the drive path

Troubleshooting

Rattling noise usually means the rotor is out of balance or the air gap is too tight. I killed power immediately. If the coil gets hot fast at 5 volts, that’s normal with zero resistance—mine literally went on fire. Drop voltage or add a current-limiting resistor if you want longer runs.

Safety

These things can accelerate fast. Keep fingers clear. When a coil starts smoking, shut it down instantly. 16 gauge wire can carry a lot of current and will get hot with no resistance. Always have a way to kill power quickly.

FAQ

Will it run on 3 volts? Yes, it spins nicely and keeps accelerating. Current stays reasonable.

Why did the coil burn at 5 volts? Zero external resistance plus high speed equaled too much current for that little coil.

Do I need a hall sensor? Not required for basic running, but it cleans up timing and is what I plan to add next.

What’s the best air gap? A mediocre one—around 1–2 cm worked fine. Closer than that and it can get noisy.

Related on this site

• How to Build a Pulse Motor: Complete Beginner's Guide
• Pulse Motor vs Bedini Motor: What's the Difference?
• Best Wire Gauge for Pulse Motor Coils (AWG Guide)
• Using a Hall Effect Sensor in Your Pulse Motor Build
• How to Wind Coils for a Pulse Motor (Step by Step)

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