Joule Thief

[Mk1]

Bifilar for the two driving coils only - collector coil is a stand alone.  This is where you wrap one two or three coils.  Any load on that coil will effect the gains on the other coils.

Ok , first 2 jt coils 1 to collector one to base with the resistor, basic jt . other coils are pick up coils only connected to bridge or any diode , otherwise it will not show on the meter.

[Pirate88179]

@ Mark:

Thanks for repeating this.  Most don't seem to get it.  We need the rectifier to see what is really happening or, maybe lighting a bunch of leds says the same thing but, testing with it rectified is the way to go.  Thank you.

Bill

[electricme]

@all,
Gadgetmall has been very very sick, I last heard from him about a week ago, since then nothing.

jim

@ Koen1,
240v query.
How did I know the difference between both power supplies? Well it's hard to discribe, this is over 50 years ago,.

All I could say is I felt the power in Lae as smooth and effective, the power in Australia felt like it was harsh, as though it had a wild beast inside it, with a sharp saw tooth about it, like I said, difficult to discribe.

Koen, your post on P(376) you mentioned also that the voltage is averageing out at 230v, funny that because in Australia this is also occuring, there was an article in the Silicon Chip about this, I wasnt aware of this situation until I read it last week, so I am confused like you hmmmmm, wonder whats going on here? Big picture wize.

No, the Grid is powered by Hitension AC, 33,000 volts, this drops down via transformers to different feeds to eventually 240v (230V) 50cycles (Hz for those who like Hz lol.) for Town and City usage
There is 3 phase power line poles along my street, there is a transformer on 2 poles about a 100 yards away from me, this supplies a 3 phase to the town, I'm on a single phase.

I will answer your other post further down the page shortly.

jim

[Pirate88179]

@ Jim:

When I worked for my father in his NJ machine shop, we installed 3 computer controlled diamond surface grinders.  they had all sorts of problems and the techs came down many times from Boston (at our expense) to try to fix them.  well one bright guy decided to put a metering device on the grid supplied power to see what was actually powering the machines.  we found out that, even though we were paying for 220volt 3 phase power that many times during the day, it dipped to 175 volt and also sometimes went to 290 volt.  Now this was 3 phase and it did a lot of damage to the computer circuits when this happened.  The manufacturer said it was not their problem because the machines were designed to operate on a certain range of power input.  Well, a spokesman for the local power company said that, under their requirements, they only had to supply an average voltage of 220 3 phase as measured over a one month period.  He said it might go as low as 110 volts and as high as 350 volts and still be in "acceptable levels".

Bottom line is we were on the arm for all machinery repair due to this fluctuation.  After a while, I replaced the internal components with stuff that could handle the real ranges a lot better.

So, we never really know what we are getting from the local power company.

Bill

[TheNOP]

Gosh! ...I'll just have to scrape the paint off one and check.  ..and it doesn't appear to conduct.

i did not scrape the paint off it, i broked it and checked for the resistance inside.
core capable of higher frequency will be less conductive, more resistance.

i rechecked, the piece i found back is about half a yellow toroid, resistance show 32k ohms