Bedini Schoolgirl

[kumaran]

Recheck your circuit & component

Hi ERKAN,

I think you have fried the transistor. If you use 2N3055 transistor, do the following steps to check if the transistor still ok or not.

1. Set multimeter in diode mode.
2. Touch positive probe to transistor base and negative probe to transistor.
3. You should see readings or beep sound from your multimeter.
4. Now touch negative probe to transistor base and positive probe to transitor emitter.
5. There shouldn't be any readings or beep sound from multimeter. If does then replace new transistor.

Other info :

• Bifilar wound 850 turns of #23 & #26 clockwise direction.
• Use battery 12VDC only.
• Positive #26 goes to 680 ohm then to transistor base and negative #26 goes to battery negative.
• Positive #23 goes to battery positive and negative #23 goes to transistor collector.
• Small push to rotor should rotate now.

Make the rotor rotate first then go for tuning.

[ERKAN]

Not Working

Checked everything what you guys said and still nothing. When I disconnect the resistor I get 0A for the circuit and 12V at transistor.

[ERKAN]

Not workin

I pulled everything appart. Then I took new diode, resistor and transistor. Now I get 111mA and litle of humming when magnet is on the coil. I also replaced the neo magnets with normal ones. Neo magnets were very small and the new ones are 3/4" diameter. But whele is still not spining. WhenI put the coil next to the magnet it repels. I don't have a core in my winding.
I have one question: "If you disconnect smaller wire winding should motor work?". When I disconnect the second coil I get 0 amps. If circuit is energized and than connect the smaller wire winding it is still 0 amps. I have to turn the power off and than urn it on in order to work.
What am I doing wrong?

[kumaran]

Hi Ekran,

Can you give details of your setup?

1. No of turns for coil winding?
2. Gauge of wires used?
3. Components used like transistor, diodes and others?

Too little windings for trigger coil will not trigger the transistor. TO3 transistor casing is a bit tricky to identify base and emmiter. Check everything again. Bedini SSG should start easily if the components connected correctly.

[ERKAN]

Not Working

I am using transistor 2n3055, diode 1n4001, resistor 680 ohm, bifilar coil with 680 turns of #23 and #26. Rotor is wheel taken from inline skates with four 3/4" round magnets from Home depot. I don't have a core because I could't find R60 welding rods. Before I tried to use bolt but somebody said it is better not to use anything if you don't have R60.

[Aaron]

use a solid core for now

Hi Erkan,

The welding rod is better than solid core, but and air core won't let the magnet induce enough to trigger the transistor. I would find some solid piece just for now at least until you get welding rod. I think that might do the trick.

[obelix]

hello all,

until you receive yours R60 test with some nails, that does the trick for me !!

Obelix

[amigo]

I have used galvanized steel wire (tie wire for fence repair?) found at Home Depot, for my core. I find it working well (or better than the welding rods) and it's easier to cut.

[Shamus]

Like Aaron said, you have to have some kind of magnetizable metal for your core. The important thing is that it should resist the formation of eddy currents, so any of the things suggested above should be sufficient to get it to work.

[ERKAN]

not working

I tried putting the stainless steal bolt but still nothing. I start measuring voltages and currents in the coil and system so this is what I have:

12V battery DC
Current measured at the negative leg 111mA DC(I cannot measure AC)

#23 wire coil
Voltage DC 0.34V
Voltage AC 15.7V
Amperage DC 111mA

#26 wire coil
0.457 mA DC
Voltage AC 14.7V
Voltage DC 3 mV but this can be a mistake so read it 0.

Resistor
Same values as #23 wire coil

Diode reads some 0.7 VAC, 358mV DC

Just a reminder that for AC scale is 200V so it shows only one decimal.

Emitter collector and base collector show the same
25V AC only when I put positive read on collector and negative on emiter or base. When I flip it shows 0V.
11.47DC, positive lead on collector. It shows negative when I flip the leads.

Base emitter 0.3VDC and 0.1 VAC.

[adam ant]

i believe that the collector to base should only go one way. you said that when you reverse it you get a negative number, this shouldnt be the case, it should read 0. it sounds like your transistor is fried.

[adam ant]

yes,

base to collector should only read one way (not collector to base)
base to emmitter should read only one way (not emmitter to base)
emmitter to collector should read only 0, either way. (E to C only conducts when B is triggered)

i hope this helps

[ERKAN]

Not Working

These readings I obtained while the battery is connected. When the battery is off everything is as you said.

[adam ant]

DOH!! i thought i was on to something there. sorry i couldnt help.

[Shamus]

One step at a time...

@ERKAN: If it's not turning, then there's a few things to look for:

• Bearings. Your rotor should freewheel very easily; if it doesn't spin for at least a minute after giving it a good push then you need to fix that. The SG doesn't develop much torque, and it can't overcome bad bearings.
• Coil. You have to have enough turns on your coil to induce a current when a magnet passes by it. I've been able to get by with only 600 on my first attempts, but I had to give it a good spin to get it going. Also, you absolutely must have some kind of magnetizable core. Air cores won't work.
• Magnets. They should be strong, but not too strong. Neodymium magnets are too strong. If the ceramic magnets aren't working, then perhaps you can double or triple stack them so they're at the right field strength (I don't know what that would be, since I don't have the equipment to measure magnetic fields).