Joule Thief

[Pirate88179]

0.6uF seems very high.  Are you sure it isn't 0.6nF?

That is why I don't use a cheap meter from ebay.  The one I wanted is like $150 or more.  I bought a cheap one a few years ago and, I can measure the same cap 10 times and get 10 different measurements.  Also, it will not do supercaps which is what I was using mostly at that time.  I still have it as it does have a nice blue lcd display that I might be able to use elsewhere.

Bill

PS  I am not disparaging Teo's meter as I have no idea what he is using.  I just know that I tried to give mine away to one of the electronics guys at work, and he did not want it as he said it was crap.  Mine cost $25.00 a few years ago.  It runs off a 9 volt battery.

[tgraca]

0.6uF seems very high.  Are you sure it isn't 0.6nF?

Well, that's what my LC meter shows... The battery may be low... I changed the battery and am getting 3 uF (not nF).
I tried my other LC meter and it's showing about 4 uF... I guess I need to find a descent meter for capacitance.
I do know that these inductors act as if they have some capacitance. I can see it, so it must be in the uF range.

[tgraca]

That is why I don't use a cheap meter from ebay.  The one I wanted is like $150 or more.  I bought a cheap one a few years ago and, I can measure the same cap 10 times and get 10 different measurements.  Also, it will not do supercaps which is what I was using mostly at that time.  I still have it as it does have a nice blue lcd display that I might be able to use elsewhere.

Bill

PS  I am not disparaging Teo's meter as I have no idea what he is using.  I just know that I tried to give mine away to one of the electronics guys at work, and he did not want it as he said it was crap.  Mine cost $25.00 a few years ago.  It runs off a 9 volt battery.

lol... damn... I guess I am in the market for a descent LC meter... Any suggestions? I am pretty sure these work well with ohms and
mH, but I would be willing to find a better one just to make sure... The LC meter is the most important tool to me...

[MarkE]

Well, that's what my LC meter shows... The battery may be low... I changed the battery and am getting 3 uF (not nF).
I tried my other LC meter and it's showing about 4 uF... I guess I need to find a descent meter for capacitance.
I do know that these inductors act as if they have some capacitance. I can see it, so it must be in the uF range.

The numbers seem way off.  The resonant frequency of a coil that has 3mH inductance and around 1uF capacitance is around 3kHz.  If your JT oscillates much faster than 3kHz then you should be very suspicious of those readings.  Are you measuring the capacitance with the coil isolated on the bench, or in circuit?

[MarkE]

lol... damn... I guess I am in the market for a descent LC meter... Any suggestions? I am pretty sure these work well with ohms and
mH, but I would be willing to find a better one just to make sure... The LC meter is the most important tool to me...

If you can afford them, Fluke and Keysight make reliable instruments.