Joule Thief

[xee2]

[@ freepow

I am measuring with probe tip to Emitter and aligator to collector.

Thanks. Thar is the best photo I have seen of the collector spike. If you have a divide by 10 probe, you might want to see what the voltage across your 30 turn pickup coil is like. I suspect it looks the same but with higher voltage. But, make sure not to exceed the max voltage input for scope.

[IotaYodi]

Is there any device a person could use outside of an insulated screwdriver

I didnt know these little cameras were that high.
When you use a screwdriver to discharge you take a chance on degrading or destroying the cap if there is a substantial amount of voltage. If you have a high mfd cap,then even at low voltage it can cause an extreme discharge melting the screw driver. These kinds of caps can kill you even with a normal healthy heart. You can make a discharge tool in different ways. Heres a simple one

One can make a capacitor discharge tool with two insulated alligator clips, about 16 inches of 14 gauge stranded wire and a 10,000 ohm, wire-wound, 10 Watt resistor. Solder an insulated alligator clip to either end of the insulated wire. Then cut the wire about 7 inches from one end, and solder the resistor in place. Now wrap the resistor and solder points with at least three layers of ELECTRICAL TAPE.


The higher the resistor value the longer it takes to discharge. Higher voltage and current caps would need a higher Resistance. 

[protonmom]

Thanks IotaYodi,
that sounds like something even I can do.  Will have to give it a try.
Guess I was just looking for something to add to my tool collection.  I have a third hand on the way, so ...HEY!   More tools, more goodies.  Maybe I will even make something with them some day.

[kamax]

@gadget, or anyone else who might know: 
Is there any device a person could use outside of an insulated screwdriver, that can discharge those cam caps safely?  Perhaps some sort of wooden tongs?  I have only opened three of my cameras, so far.  I have not yet been shocked, fortunately.  I try to be careful, yet I know it only takes a moment of looking the other way....
I thought about making some wooden tongs, but not sure just how to do it.  I do have insulated screwdrivers.  Do I need to add an extra layer of elec. tape around them to be sure they are safe?

If you use only one hand and don't have the foots in water, generally there is no prob. Your body just need to be insulated from a ground like water, a piece of conducting metal, earth if you are outdoor...

The electricity always take the less resistive way. If you are not grounded(like with shoes) there is no way, except if you use 2 hands and touch + and - with different hands, in this case your body act like a resistor between your left hand->left arm->chest->right arm->right hand.

[jeanna]

I just  burnt out my last 3055

I got  it to work for a little while .

On  my last  try  I was lighting  2 LED arrays

They  were lighting up pretty good ....... but not that much better than  I have been able to do with 2 AAs
I tried  just  a little less resistance to the  base and  the  transistor blew out .
I am not sure of the voltage I was getting .
My meter only  goes to 600 V    It  started beeping  as soon as  I  got a little  light  from the first LED array .
I  must  have had some pretty  big spikes .


I did not have any time to  try  any feedback or  flyback

gary

I am sorry to hear this, gary.
The part that is unclear to me is why you are expecting to get more volts from a higher voltage input battery.

This is a switch circuit, right?

All you are doing with the battery is switching the transistor on and off.
The voltage going into the secondary is coming from the inductance of the toroid not the voltage from the battery.
This is the reason the battery is not drained by what the secondary is doing.
Said a different way, this is how the amps draw can go down or remain unchanged with more lights coming off the secondary.

I never tried this, but my guess is that the 450 volts which come from my fluoro tube inductor would drain the battery as quickly with or without the tube actually there... (because it is the transistor that it is working and nothing more.)

In fact, if I check the battery volts when the light goes out then forget to remove the battery, it is significantly drained later with no light on any more.

I have never said this before to you because I just figured there was something in your feedback/flyback that was involved. But you just said you had not set them on when the transistor blew out.

Would you be interested in trying to explain it to me?

thank you,

jeanna

I just saw this on introvertebrate's bedini part2
I copied it directly from his answer to someone about why the neon in parallel to the base resistor.

A neon bulb only conducts when the voltage goes over 90v. If you disconnect the charging battery then the high voltage spike from the coil won't have anywhere to go so it zaps your transistor and fries it. If you have a neon bulb in the circuit it allows the spike to go around the transistor and protects it. It does not conduct electricity as long as the charging battery is connected and a resistor won't work either... it has to be a neon bulb.

Maybe this is what you need to do. It doesn't stop the bedini from charging etc.

j