Bedini Schoolgirl

[BinzerBob]

60 Volt max issue

I think I figured out why my circuit only seems to product a maximum of 60 volt spike (radian energy).

The NPN Transistor 2N3055 is rated for 60V. Above that voltage, it probably breaks down and shorts out.

I was not able to find a 40 V neon bulb, so I am using a 90 Volt one for now. Any comments on my hypothesis about why the maximum of only 60V?

[citfta]

Re: 60 volt max issue

Hi Bob, Congratulations on getting your SSG to work. Your problem is most likely caused by your solid bolt for your core. The solid bolt allows a lot of eddy currents to flow in it and robs the coil of its magnetic ability. Your circuit will work much better if you can find some kind of soft iron material to use as a core. Even a bunch of pieces of old coat hanger wire will be better than the bolt. As far as the transistor goes if it's max voltage is ever really exceeded then the transistor is fried and you will need a new one. By the way the max ratings are approximate and are suggested by the manufactorer. They are max voltage and current ratings you are supposed to design your circuit around. Good luck, citfta

[petey256]

Hi, I still cant get my ssg to work. I am thinking about scraping the whole thing and starting over. One thing I dont understand is that I have the wires coming off the right side of the coil towards me and I found the top of the coil was south not north. When I jumped across the collector to the base of the trasistor it made the wheel jump but also pulled it towards the coil. Acording to the schematics it should produce a north field.

[Sephiroth]

ah... ok, then try swapping around the wires on the coil... ie the wire currently connected to the primary positive needs to go to the collector and vice versa.... do the same for you trigger winding... this will reverse the polarity of your coil.

[ren]

I think I figured out why my circuit only seems to product a maximum of 60 volt spike (radian energy).

The NPN Transistor 2N3055 is rated for 60V. Above that voltage, it probably breaks down and shorts out.

I was not able to find a 40 V neon bulb, so I am using a 90 Volt one for now. Any comments on my hypothesis about why the maximum of only 60V?

The comment about your choice of core material is spot on.

The voltage rating of your transistor is mostly relevant to your input power, and not to the spike which is directed away from the transistor anyway. If the spikes destination (charging battery/capacitor) is removed then the spike can damage the transistor, hence the neon bulb.

[boguslaw]

I found something interesting...

OK, probably I've found something interesting about schoolgirl circuit.But first please do a simple test. Connect second neon in place of charging battery and adjust POT to see light in neon. Please tell me what you see.I see very weak light in on of then neon terminal. Is that correct ?

[theremart]

OK, probably I've found something interesting about schoolgirl circuit.But first please do a simple test. Connect second neon in place of charging battery and adjust POT to see light in neon. Please tell me what you see.I see very weak light in on of then neon terminal. Is that correct ?

Much better to put a nite light in place of the charging battery... or use the 1 ohm resistor test found on the yahoo monopole 3 group.

I tried the neon on mine and I blew my transistor. I might be driving a much higher voltage than you but in my old age I do try to smoke less transistors

[patmac]

Hi, I still cant get my ssg to work. I am thinking about scraping the whole thing and starting over. One thing I dont understand is that I have the wires coming off the right side of the coil towards me and I found the top of the coil was south not north. When I jumped across the collector to the base of the trasistor it made the wheel jump but also pulled it towards the coil. Acording to the schematics it should produce a north field.

Hey. My Bedini use South Pole, I have no noted any difference, logically is necessary invert electrical poles to get it work.

[boguslaw]

My Bedini schoolgirl circuit modification

Hi,

I will describe what I have.I had mistake placing transistor in reverse so E and B replace each other. Surprisingly it works!


Even more it has a sweet spot when the wheel is not required to maintain oscillations. Second to note is much high intensity of output oscillations - it easily lights neon connected in place of charging battery.

It also seems to behaves quite differently then with normal Bedini schoolgirl circuit. Battery "eats" voltage and very fast rise even to 15V and then stays long on this.

I have to confirm if charging is also faster, because after disconnecting battery voltage slowly drops to original value, but I only tested it for a few minutes.

If I remove 1N4001 diode (which is 1N4002 in my case) the circuit is not able to self-oscillate - it looks almost the same as original - wheel is rotating and a sweet spot may be found. However there is a difference - neon connected to the output in place of charging battery is lighting very bright with even a purplish accent.

The problem is with POT, I fired a few of them. 1/4W POT is not good in that modification.

[BinzerBob]

Iron Core

Ok, I will change my iron core (solid bolt) to the type specified by the Bedini literature. I will paint the welding rods first (allow them to dry)then make the core.

My motor with the iron bolt, is charging batteries. I am trying to condition a 9.6 V 1.3 Ahr NiCad. Should I abandon the NiCad and move to a lead Acid type battery? So far I have noticed that the discharge voltage of the 9.6 volt battery is held mostly above 10 Volts (with a discharge rate of .04C ie about .053ampre), then when the voltage gets to 9.5 volts it dies very very fast.

With an imput current of .3ampre and at 12volts the iron core get just a bit warm, which are the eddies current shorting out.

Thanks for your help.

[theremart]

Nicad..

Ok, I will change my iron core (solid bolt) to the type specified by the Bedini literature. I will paint the welding rods first (allow them to dry)then make the core.

My motor with the iron bolt, is charging batteries. I am trying to condition a 9.6 V 1.3 Ahr NiCad. Should I abandon the NiCad and move to a lead Acid type battery? So far I have noticed that the discharge voltage of the 9.6 volt battery is held mostly above 10 Volts (with a discharge rate of .04C ie about .053ampre), then when the voltage gets to 9.5 volts it dies very very fast.

With an imput current of .3ampre and at 12volts the iron core get just a bit warm, which are the eddies current shorting out.

Thanks for your help.

Lead acid batteries are much better with the Bedini.

[elias]

Much better to put a nite light in place of the charging battery... or use the 1 ohm resistor test found on the yahoo monopole 3 group.

I tried the neon on mine and I blew my transistor. I might be driving a much higher voltage than you but in my old age I do try to smoke less transistors

Tired of frying transistors! Anyone has any idea how to burn less transistors?
The neon simply won't handle voltages more than 12 volts!

Elias

[Sephiroth]

try 2 neons

[elias]

try 2 neons

Well, Thanks, I'll do but will it protect my precious transistors? I don't want to burn my remaining two transistors. maybe I'll try three!

[Sephiroth]

can't say for sure but 2 neons in parrelel should offer more protection. Are you using the 2n3055s?