Bedini Schoolgirl

[theremart]

RE: what did you do wrong?

Hello everyone,
this is my first post but i've been interested in these kinds of underground electronics for a couple of years.

i finally had a few spare hours to tinker with this bedini motor circuit. i am currently low on money so i was just using the materials i had in my shop... the bifolar coil is too small w/ too few wraps.
as soon as i fired her up, the electromagnet coil (bigger wire) would trigger the trigger coil (smaller wire), which switches the transistor and the cycle continues. The bifolar coil hummed and the rotor seemed to have little effect with regards to the transistor swithing.

what did i do wrong?
do i just need to get the correct gauges and length of wire.
what keeps your guys' coil from entering this "self-resonance"?
the induction from the main coil to the trigger coil is much greater than from the rotor magnets.

If you are using neos, move the coil back away from the magnets at least a 1/2 inch.

It helps to understand your circuit if you can give us pictures of it.

I have found the hard way if you skimp on the parts you get skimpy results. It is best to gather the various parts that are right to do the job then go about it.

Please post a picture of what you have. Also list the materials that you used.

Hang in there we are pulling for ya, took me about 2 weeks to get my first one going. I also had too little wire on the coil..

Mart

[Hans]

excited like a child :-)

Hi there Jetijs, Theremart and others !

Yesterday I completed my construction of the SSG, and the moment was there to give it a try. The model worked right from the start, so I jumped with joy !
I have the technical insight of a snail, but after reading and rereading and carefully following the instructions, I managed the very first time.
Parts I used:
- coil wire #20 (to + of battery)
- coil wire #25
- about 600 parallel coin windings
- coin length 2 1/2 "
- 2 weak iron bars and some galvanised wire as coin rods
- tranosistor 2N3055
- resistor 47 Ohm
- diode 1N4007
- 12V lead acid battery (small 9V battery also worked)

Made a small film with my camera:
YouTube - Bedini Simplified School Girl (Monopole) Motor

[theremart]

Hi there Jetijs, Theremart and others !

Yesterday I completed my construction of the SSG, and the moment was there to give it a try. The model worked right from the start, so I jumped with joy !
I have the technical insight of a snail, but after reading and rereading and carefully following the instructions, I managed the very first time.
Parts I used:
- coil wire #20 (to + of battery)
- coil wire #25
- about 600 parallel coin windings
- coin length 2 1/2 "
- 2 weak iron bars and some galvanised wire as coin rods
- tranosistor 2N3055
- resistor 47 Ohm
- diode 1N4007
- 12V lead acid battery (small 9V battery also worked)

Made a small film with my camera:
YouTube - Bedini Simplified School Girl (Monopole) Motor

Congrates...!!!!!!

I know how it feels to see that wheel turn the first time!!!

[petey256]

Bedini does not run

Hi, Im a new member and have been inspired by this forum to build my first sg and start experimenting. Looks so simple but I can not get it to run.Im using a skateboard wheel with four magnets ducktaped to it. I was using a 16 inch bike rim but changed to a skateboard wheel when I couldnt get it running. I have about 900 turns on the coil and am using a in914 diode with a 100ohm resister changed from 470ohm when it didnt work. I am using a 3055 transistor. I see nothing on the base and 12volts on the collector and emitter.
The coils are not shorted together or open. If I read across the diode I see a little over 100 ohms so Im reading through the resister and coil across the trigger side. My battery negitive side is my ground. I have no load on it and am using a sealed lead acid 12volt battery as my source voltage. Does anyone have any ideas? Thanks petey256

[Sephiroth]

Hi Petey...

were you using a neon in the circuit?

[petey256]

No I wasnt. I just checked the transister and it is not open or shorted.

[Sephiroth]

try BRIEFLY shorting the base to the collector... if the transistor hasn't fried then the coil should repel the magnet on the rotor...

though if your ssg has no load and no neon the chances are your transistor is going to die...

[petey256]

What kind of neon and where could I find one. I read to use one but it is not in the schematic. I looked when I was at radio shack but could not find one rated at 90volts dc. Maybe I was looking at the wrong thing. Also where do I connect it between emitter and ground or collecter and the small wire coming off the coil? Thanks for the quick response I wasnt sure this thread was still active.petey256

[petey256]

I shorted the base and collector like you said and the wheel moved. What does it mean and can I connect something besides a neon to see this run for now like a dead 6volt battery? Thanks

[Sephiroth]

yeah... the 6 volt battery should be fine..

sounds like your transistor is ok (as long as you shorted the base and coolector and not the emitter an collector)

by shorting the base and collector you allow current to flow into the base and out through the emitter... this is what turns the transistor on during normal operation except the triggering current comes from the trigger coil when a magnet passes over it.

Not sure what the problem is then... what kind of magnets are you using and does your coil have a core?

[petey256]

Im using radio shack rectangular magnets with the hole in them. So the problem is on the trigger side of it?

[Sephiroth]

It sounds like the problem is on the trigger side... is the trigger wire on the positive side of your coil going to the resistor (then to the base) and the other connected to the emmitter?

Does your coil have a core?

Edit : meant to say positive side...

[petey256]

I put welding rod in the center of my coil and the wire coming from around the right side of the coil is connected to the base and the big wire is connected to + side of battery. The wires coming from around the left side are connected to the emmiter and the big wire is connected to the collector.

[petey256]

Is it possible I have my coil upside down?

[BinzerBob]

Voltage

I Finished my SSG Bedini Motor, hooked it up, and it fired up in one shot. I was impressed that it worked first time.

I have a question about the voltage. I read that the motor has a cpacity to shock. Mine dosen't have this capacity to shock, it only seems to develop a maximum of 60V.

I do not have a scope but if I replace the charge up battary with a capacitor to see what the max voltage is it will only register 60V.

My coil is 650 turns or more, #20 and #24 wire bifilar. Rotor spins at about 1000 rpm, 4 magnets (standard type). Diameter of the rotor is 5". I am not using a Neon Bulb (I could not find one yet). I am using a diode to protect my transistor.... maybe this is the problem?

The run battery is 12V and with the resistance set at 1000 ohm the motor draw only 180 mA.

The core of my electromagnet is a solid bolt. It extends about 1.5" on the south side of the coil so that I can mount it (I use the threads of the bolt... but maybe this is the problem, as I am not using the welding rods?)

I can post something on u Tube if clarification is needed.

Any suggestions?