Amp Funnel Coil Powers 8 Neo Cube Magnet Pulse Motor to 1300 RPM

Hook

I didn't expect much when I threw eight neo cubes on this rotor but the amp funnel coil proved me wrong. We hit 1300 RPM and pulled some serious induction.

Watch this experiment

I fired up the motor generator, let it rev while watching the oscilloscope, and measured AC voltage straight off the coils. The shaft started shaking right around 1200-1300 RPM so I had to back off. You can hear it scream in the video.

What you'll learn

How an amp funnel coil behaves on the generation side, what eight neo cubes do for smoothness and power, and why the waveform loses its bottom spike at higher speeds. All straight from the bench, no theory fluff.

From the bench

The drive coil is 300 turns of 20, 18, and 32 gauge wire in parallel for a total of 900 turns. The amp funnel coil starts at 28 gauge in the middle, steps to 26, then 24 on the outer rim. There's also a thin induction coil with 32 and 26 gauge plus another with 24 and 32. I used a bridge rectifier on each set and metered the AC voltage directly off the coils. The rotor is an eight magnet setup and I compared it mentally to a rectangle magnet version I have.

How it works / what we changed

I pushed 50V through the funnel coil when I tried it as a drive coil and only got about 400 RPM. Switched it back to generation and the real fun started. The coil behind the drive coil picks up heavy induction right after the drive pulse. On the scope we saw a nice smooth 500 peak-to-peak volts. At higher speed the bottom spike cuts off and we lose about 200 volts peak-to-peak. The drive coil lights a bulb while the induction coils generate. When I connect the coils through the bridge rectifier to a 500F 16V capacitor bank it charges at a decent rate for induction. Hook the coil straight to the cap bank and it loads up in about a minute.

Cube magnet pulse

The cube magnet pulse from the eight neo cubes gave surprisingly strong results. I honestly didn't think I'd get that much juice but it runs smooth and hits 1300 RPM before the shaft shakes. Compared to the rectangle magnets I have, the cubes are smoother even though the rectangles would probably give higher readings. The pulse is strong enough that stopping the rotor by hand would cost a finger.

Funnel coil power

The funnel coil power comes from the way it's wound like a cone or megaphone. It starts small current-wise in the middle at 28 gauge and ends bigger with 24 gauge on the outer rim. Even though current is limited by the thinnest strand, the thicker outer wire gives a lot of benefit on the generation side. When used as a drive coil with 50V it only reached 400 RPM, but as a generator it performed well and helped produce the 100-116V AC readings we saw.

Neo cube magnet

These neo cube magnet pieces are glued or arranged into the eight positions on the rotor. They're strong and give a clean pulse. The rotor becomes heavy from the magnets which helps it act like a flywheel once spinning. Even with no power applied it kept turning for 8-9 minutes while generating, though induction does load it down a bit. The induction from the coils is partly coming from the drive coil itself when the magnets pass.

Builder checklist

• Wind the amp funnel coil starting 28 gauge center stepping to 26 then 24 outer
• Use 8 neo cube magnets on the rotor, balance as best you can
• Place one induction coil directly behind the drive coil for extra pickup
• Bridge rectifier on every output set
• Scope the waveform right after the drive pulse
• Have a big capacitor bank ready (500F 16V worked for me)
• Watch for shaft shake above 1200 RPM

Troubleshooting

Shaft shakes at 1300 RPM — it's probably not perfectly round. The bottom spike on the scope disappears at high speed and you lose about 200V p-p. If it slows constantly with no power it's acting like a loaded flywheel from the heavy magnets and induction. The light flickers and the negative spike can vanish on the scope when the drive coil is loaded.

Safety

This thing gets powerful fast. At 1300 RPM if you try to stop the rotor with your hand you could lose a finger. Keep clear of the spinning magnet rotor. The voltages we saw hit over 100V AC and 500V peak-to-peak on the scope so treat all leads with respect. Capacitor bank holds charge — discharge safely after tests.

FAQ

Why does the bottom spike disappear on the scope? It happens when the motor gets going fast enough. We lose about 200 volts peak-to-peak but the top part stays strong.

Can the amp funnel coil run as a drive coil? Yes, with 50V it spins the motor but only reaches about 400 RPM. It works much better on the generation side.

How long will it spin with no power? About 8-9 minutes like a flywheel before it slows too much, even while generating into the coils.

Will rectangle magnets give better results? They should give higher readings but the neo cubes run smoother in this eight-magnet setup.

Related on this site

• How to Build a Pulse Motor: Parts, Coil Gap, First Spin
• Pulse Motor Rotor Design: Magnets, Materials and Balance
• Best Neodymium Magnets for Pulse Motor Rotors
• Pulse Motor vs Bedini Motor: What's the Difference?
• Reading Oscilloscope Output on a Pulse Motor
• How to Maximize RPM on Your Pulse Motor

Watch this experiment on YouTube

• ▶ Watch full on YouTube