Joule Thief 101

[sm0ky2]

riotous man,  and groovy. 

here's one for ya.
Metal Desk (wasn't dodged, just seemed irrelevant, but since challenged....)

As was discovered upon placing the computer onto an insulating support
The metal case of the computer is charged up to ~45V above the rest of the house.
This is generally unnoticed with the small computer. However the large metal desk acts as a capacitance.
When the desk is not insulated from the computer case, it too measures at around ~+45v
this was in reference to both house ground at the plug, as well as the floor, the door knob, and several other
random points of reference.

It was presumed that some low-current flow forms between the power supply plugged into the wall
grounded through the circuits, to the case, then the desk.
this is all extremely large compared to the JT which uses the desk as its' "battery".

[tinman]

 author=MileHigh link=topic=8341.msg474965#msg474965 date=1455982986]




MileHigh


The term !blocking oscillator! is a bit of an incorrect description.The current flow isnt actually blocked,the current path is disconnected/becomes open--nothing is actually blocked. When the current path becomes open,no current can flow,and so the magnetic field collapses. But it is what it is.

ROTFLMAO, you are not at the point in your understanding where you can properly name a circuit by it's type.  I am not going to try again because there are other issues at play which result in you making that foolish statement.

Odd words from a man that needs dots on coils to work out how an SS SSG circuit is wired.
Or from some one that dose not even have a JT circuit of there own,even though(as you say) is only 5 components.

Two weeks ago people were talking about how a Joule Thief runs like they were from another planet - Planet Bizarro.  And now people understand how a Joule Thief actually works, they understand how its operating frequency is determined, and they understand how it has absolutely nothing to to with resonance at all.

Well i never actually got into the resonance thing,as i dont think that is important towards efficiency,nor plays a key role in it. But then again,we all know the kid on the swing theory,where resonance plays a key roll in efficiency. I mean,you wouldnt want to try and push the kid forward again when he was only half way back on the return swing--would you. You would wait until he hit his return peak,and then give a little push as he just started the cycle all over again. You could also give that little push in the right direction when he reached the mid point in the forward swing--this would be the zero volt line on the AC sine on every down slope crossing.

After all, this is like a circuit with five components and it should be understood.  But of course there was a huge amount of push-back and it was a total slog to get these basic concepts across.  It reminds me a bit of EMJunkie and the coils discussion.  I called his bluff and asked him how a circuit worked that consisted of only two components, a voltage source and a coil, and was unable to answer the question after he was talking about coils for months.  It just shows how easy it is for people out there in YouTube land and elsewhere to deceive people that want to believe.

Well there could be two answers to that one MH--you were not clear enough in your description.
Was the voltage source AC or DC ?
As you said !voltage source and coil!,im guessing there was no core for the coil?.
If the voltage source was DC,then you just get a resistive heater with a stable magnetic field.
If the voltage source was AC,then you would have a resistive heater with an alternating/varying magnetic and electric field.

The Joule Thief in it's normal operating mode is understood.  What happens when a Joule Thief changes operating mode at very low voltages is not understood, and it will be up to the people on this thread if they want to pursue that investigation at all.

You mean-not understood by your self MH. I mean,you even said in a reply to Mag's scope shot that you were not even going to try and work it out--but yet,tell me im wrong-->even though you have no idea what is right

Your sarcasm about the incorrect schematic is misplaced.  All experimenters should do that otherwise you end up with mass confusion.  Look at your push-back on the question of the dots for the transformer.  It's not the fact that in this case it was not to difficult to discern, in other schematics it will be difficult to discern.  It's all about the principle of the thing and good practices.  Shame on you for such a sucky attitude - put on the bloody dots.

Some time's MH you become to critical when you find you made a booboo. Like i said,how would you determine the resistance of a 10k VR. It could be .1ohm or 10 000 ohms--but as long as i put it there in the schematic,it's all good.I could turn that pot down to it's lowest resistance,and then the two circuits are the very same--i turn the pot to 1 ohm resistance,and now there different lol. But dot's for such a well known simple circuit?--really
Do i need to come and write keyboard on your keyboard so as you know what it is ? Should i put a sticky note on it for you,saying belongs on computor desk--just so as you know where it go's-like the wires on the SS SSG circuit.. do i really need to place dot's on the bifilar coil for such a simple and well know circuit ?.

You have never seen a depleted battery at 1.5 volts?  How about I interrupt your stream of consciousness with some reality:  Lots of people will pop in a fresh or slightly used battery in their Joule Thieves.  It's supposed to be designed to give you decent performance over a voltage range, not just at a certain low voltage.  Welcome to the real world.

The real world MH,is that most people want there JT to run LED's from nearly dead batteries.
Reality check MH-->If people wanted to use good batteries to run LED's,then why worry about a JT (or any other)circuit at all ?,as more components results in more losses. If you want maximum light for a minimum power cost,then you just run your LED of two x 1.5 volt batteries(using 3 volt LED's)--the best efficiency you will get. But you want to take a good 1.5 volt battery,and loose some of that stored energy in other components as well as your LED--makes no sense.

I didn't miss the schematic in your clip - stop pissing.  I was actually shocked to see a schematic in your clip and I should have remembered that memorable event. What I did do was get thrown off a few days later when you posted a schematic that did not match what transpired in your clip and I commented on that incorrect schematic.  Work on developing some effective communication skills for your audience.

Like i said MH,i turn the VR down to it's lowest resistance,and the two schematics are the same
If i go by 1 ohm intervals,do i have to post 10 000 schematics for you?. Oh how hard it would be to follow MH's rules when we put a VR in the circuit lol.

More pissing.  I just did and I practically has to pound it into your head and now you finally understand how one works.  You are welcome.

Well i have understood what a JT is for,and how it operates under conditions we all want it to operate at(other than yourself MH)for quite some time. It would seem MH,that you want to use good batteries to run an LED,so as the battery becomes run down,but not quite fully discharged,where as the bulk of us want to use as much energy from that battery as we can.
I think you may be in the minority here MH,and i think that bothers you.

Well my point has been made in this thread.

Yes--that much is clear.


Brad

[tinman]

ROTFLMAO

Don't make me laugh Smoky2.  The term "internal resistance" is used for things like batteries, not diodes.  In common electronics terminology, you never say that diodes have an "internal resistance," you talk about their I-V transfer curves or absolute equivalent resistance at a given operating point or their differential resistance at a given operating point.

Are you serious MH
Lol--you have got to be kidding me--and everyone else here.

You have seen me post enough in this thread to have a reasonable grasp of my electronics knowledge level.  So posting the "instructional material" is just you making a fool of yourself, more pants pissing.

Im sorry MH,but things are not looking bright for you ATM.
Can you calculate the !!internal!! resistance of the LED in the below graph?. I saved this page from some years back when learning all about LED's and there current/voltage curve.

Brad

P.S
Hey MH--at the end of the day,where all having fun-right?.
I mean,i love our games of tennis,and no hard feelings at the end of the day--well not on my side anyway.

[MileHigh]

If the voltage source was DC,then you just get a resistive heater with a stable magnetic field.
If the voltage source was AC,then you would have a resistive heater with an alternating/varying magnetic and electric field.

That just shows how linear and insulated your thought patterns are.

You mean-not understood by your self MH.

You have made a claim that you understand how a Joule Thief works at very low voltages.  I am calling BS on you.  Tell me, what determines the operating frequency at very low voltages?

As far as just about all of the content in your two postings goes, you can sure lay the poseur BS on thick when you want to.  It's like watching a bad actor in an amateur theater production.

P.S.:  The only feelings are frustration because of the willful ignorance.

[MileHigh]

riotous man,  and groovy.

But do you get it?