Joule Thief

[TheNOP]

I connected the meter to the ac lead and then to the last wire. That was where the drawing said to put the load. MK1 said this was the meter.

then the problem is how the coils are connect in series.

knowing that one coil must be connect to the opposite side coil (180 degree) and same for the 2 other coils.
connect to get the highest voltage for each 2 coils paires.

connect one paires to the bridge.
there are 2 ways it can be connected - + or  ~ ~, it does not matter

connect one lead of the second paires to the bridge
then check the voltage between the remaining bridge pin and the remaining lead.
change the second paires leads if voltage is small.

[Mk1]

@Jeanna

I also see that we don't check the same thing , i see your voltage readings are in ac , and i always check the rectified dc voltage, this make a use difference in the results.

Mark

If you get over 100 v ac , that should be more in dc or the same.It depends on the wave shape.

[Mk1]

@all

I have found new toroid to use , and they look even better then the green wonder.

[jeanna]

@MK1,
I was just testing for the highest. I get zeros on the dmm for vdc so I used the vac and just went for the highest value. Then I turned on the scope and read it there for accuracy. I am reporting scope measurements, not dmm, unless I say so. If so, I just did it to be expedient. I can quickly see the best connection that way.

Now, I have been using the full bridge rectifier so I don't see how you can tell me you use a bridge and I don't.

Anyway I just ruined it.

I saw it was loose and I wanted it to stay tight so I tightened it up and put a small amount of tape around the outside edge. Now instead of 75volts on the scope one pair reads 20volts the other 14 volts..

Maybe I didn't ruin it. It wouldn't turn on the string of leds, maybe the higher reading was a false reading.

I don't know.

Just for today, ALL I was doing was trying to match my MK2 with the schematic, which I find out was a complete waste of the day because it isn't supposed to match it.

I am not smiling.

jeanna

[MrMag]

any way, you got my point.
both are emiting light.



@jeanna
don't be disturbe by the bridge diode marking, ~ ~  - +
they are not input/output mark per say.
you can put ac on the - + pins and get dc on the ~ ~ pins.
the marking are only to help us to know in advance what pins will be the + and what pin is the -.

from what i make from your explanations your error is to connect the 4 leads to the bridge.
only 3 leads from the coils connect to the bridge, the remaining last lead and the last bridge pin are where you put your meter.

NOP,

It does matter how you connect the bridge to the circuit. AC has to go to the ~ ~ pins and the + - Are the DC output. If you look at how the diodes are connected you will see what I mean.
The two AC connections have their diodes positioned 1 with the anode and the other with cathode on both AC connections. The DC side have the two diodes connected anode/anode and cathode/cathode.
So, if you connect AC to the DC terminal there will be no flow through the rectifier during 1/2 of the cycle.

Tim