School girl roller skate motor



small "window coil"



roller skate motor with window coil



roller skate motor with window coil powering LED



this is one of the old coils and configurations from about 7-8 years ago using a small coil surrounding the wheel and resting on the axle. Everything else is boxed up and this is all I have besides some bike wheel stuff and trifilar oscillator circuits.

Anyway, I'm posting this just for the concept that a coil like this can be used to power an LED like in the original roller skate wheel motor but obviously not a pickup coil with a core and this doesn't cause any drag that I can notice.

The coil can be wound one way to power the LED on the power pulse or wound the other way to catch the collapsed pulse. Years ago I thought it was cool to be able to power the coil without the transistor, just connect the coil straight to the battery on both ends and the LED wouldn't light up. Then, as soon as I disconnected the battery, the light would light up. That taught me long ago that you can get work from the system when turning it off! No mystery to everyone here but that made a deep impression on me.

Looking at this coil, one may think the magnets on the rotor are what are inducing the current in the coil to light the bulb and it CAN be from that but isn't necessarily so.

This video is just the plain motor running as normal on a 12v battery.
http://www.esmhome.org/library/john-...schoolgirl.wmv
22 seconds 2.82MB WMV video format

This video shows that the coil is powering the LED with the induced current from the magnets spinning on the rotor. I disconnect the battery and the LED still lights proving that the magnets on the rotor are doing it.
http://www.esmhome.org/library/john-...irlwindow1.wmv
19 seconds 2.47MB WMV video format

This vid shows that the coil powering the LED will only power the LED when there is battery power because the light goes out when I disconnect the battery and will only light it when the power is on.
http://www.esmhome.org/library/john-...irlwindow2.wmv
15 seconds 2.08MB wmv video format

Having the coil not produce power from the magnets on the rotor but from the electromagnetic coil will cause much higher voltage from that coil than with just the magnets - or you can get a combination of both. It can charge small caps higher than the battery voltage. I had that setup charging the input battery without any timing system, just the cap was going to the battery through the diode. The input battery would climb but on that setup the input battery voltage climbed but wound up getting to be pretty fluffy and wouldn't power a load very well after a while but on the meter the voltage did go up. Anyway, just a simple thing to try and results can be had with a smaller scaled system.




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