I Ran 4 Parallel Drive Coils Pulse Motor and Got 55V 1A Out

Hook

I just got this parallel drive coils pulse motor running with all four coils hooked to one reed switch and the numbers are wild — 2.08V at 0.7A in and 55V at 1A out. Lots of iron, lots of different coil wire, and some interesting magnetic drag when I turn the voltage up.

Watch this experiment

I set the multimeters up so you can see input volts and amps on one side and the bridge-rectified DC output on the other. The scope shows the very low frequency waveform coming off the generator coils. You’ll see the rotor speed change when I add or subtract voltage and what happens when the reed switch gets overloaded.

What you'll learn

You’ll see real-time DC fluctuation between 35-56V at about 1A while input stays under 3V and under 1A. We talk about why thick wire seems to give more current, how all the iron affects magnetic behavior, and why splitting the coils onto separate transistor circuits is the next step.

From the bench

Right now the output is all DC after the bridge rectifier. Frequency sits at 41-42Hz no matter what. I’m using a four-magnet rotor and the coils sit at north, south, east, and west. One of the rectifiers was flaky so I swapped it for a sturdier one. When I pushed voltage from 2.6V to 2.7V at 1A the rotor slowed down hard and the red LED on the reed switch lit up. Dropping back to 2.3-2.6V let it recover and speed up again.

How it works / what we changed

All four coils are wired in parallel on a single reed switch. The drive coils are mostly 16 gauge with 250 turns; one is 20 gauge with 666 turns and has a trigger strand ready for a transistor. On the generator side I’ve got 20, 22, 30, 32, and 26 gauge wire with turn counts from a few hundred up to 18,000 turns of 32 gauge (over 1k ohms). The thick wire mix seems to be what lets us pull over an amp out while putting less than one in. Everything is coming from magnets moving past the coils — that’s it.

coils pulse

The coils pulse when the reed switch closes and all four cardinal directions fire at the same time. Because they’re in parallel the current demand on the switch is high. At higher voltage the magnetic drag from all the iron makes the rotor slow down instead of speeding up. I plan to split them so two fire, then the other two, for smoother operation and higher speed.

coil wire

I threw every gauge I had into these coils — 16, 18, 20, 22, 26, 30, and 32 gauge. The drive coils use 16 gauge with 250 turns and one 20 gauge at 666 turns. Generator coils have 20 gauge with 666 turns, another with 20/22/30 gauge at 730 turns each, 26 gauge at 3,333 turns, and one monster 18,000 turns of 32 gauge. The mix of thick and thin wire plus all that iron is what seems to give us the higher output current.

Builder checklist

• Four coils placed at north, south, east, west
• All coils wired in parallel to one reed switch initially
• Mix of 16-32 gauge magnet wire with documented turn counts
• Bridge rectifier on output for DC measurement
• Multimeters on input volts/amps and output volts/amps
• Scope on generator waveform to watch frequency
• Ready to add transistors for staggered firing

Troubleshooting

When I increased voltage by half a volt the rotor slowed dramatically and the reed switch LED lit solid. Solution was to drop voltage back to 2.3-2.6V range. One rectifier was giving unstable readings so I swapped it. If the motor bogs down, check for too much magnetic drag from all the iron and consider splitting the parallel drive coils onto separate circuits.

Safety

Keep voltages low on the reed switch side — it can’t handle high current for long. Watch for heating in the coils when running at higher input. All the magnets and spinning rotor deserve eye protection and a safe distance. I’m staying under 3V and 1A input for these tests.

FAQ

Why does the rotor slow when I raise voltage?

All four coils pulsing together plus lots of iron creates magnetic fluctuations that fight the rotor at higher voltage.

Where is the extra power coming from?

It’s coming from the magnets moving past all the different coil wire. We’re measuring more out than in on the bench but it’s still conventional induction.

Will you switch to transistors?

Yes — next motors will trigger two coils then the other two so it fires bang-bang instead of all at once.

What gauge wire works best?

I’m getting good current with a mix. Thicker gauges on drive and generator seem to help amperage while fine wire gives high voltage and resistance.

Related on this site

• How to Build a Pulse Motor: Parts, Coil Gap, First Spin
• Pulse Motor vs Bedini Motor: What's the Difference?
• Best Wire Gauge for Pulse Motor Coils (AWG Guide)
• Pulse Motor Rotor Design: Magnets, Materials and Balance
• Understanding Back EMF in Pulse Motors

Watch this experiment on YouTube

• ▶ Watch full on YouTube