Joule Thief

[TinselKoala]

MarkE,

Thanks, I have set up a test and the readout on the L meter did go down to almost half when the switch was closed.
This confirms that it is possible to use this method to tune a oscillator to two different frequencies just by open or
close a switch.

Thanks again.
GL.

You can also do it with a single inductor, using your switch to short across turns, or by selecting multiple taps on the inductor.

[Groundloop]

You can also do it with a single inductor, using your switch to short across turns, or by selecting multiple taps on the inductor.

TK,

Thanks for the test. Yes, I have seen this coil switching in "old" HF power amplifiers. :-)

GL.

[synchro1]

It is a reasonable guess that the "high voltage" is something he measures when the LEDs are not connected.  It is also a reasonable guess that it is less than 50V peak, which is certainly much greater than the three volts required to run a white LED.

@MarkE,

Quote from Pirate88179:

"I am even using some commercial bulbs in my lights, like the Lights of America 24 chip led bulbs and ...they are just fine with 400 volts at high freq.  My bedside table uses 2 of those bulbs and...I have been using it every night for many years and...the bulbs still work. (still using the original D cell battery also)".

Pirate's running a 120 volt AC LED bulb at 400 volts.

[MarkE]

@MarkE,

Quote from Pirate88179:

"I am even using some commercial bulbs in my lights, like the Lights of America 24 chip led bulbs and ...they are just fine with 400 volts at high freq.  My bedside table uses 2 of those bulbs and...I have been using it every night for many years and...the bulbs still work. (still using the original D cell battery also)".

Pirate's running a 120 volt AC LED bulb at 400 volts.

That's not something that I would do.  The electronics in a 120V LED won't be very happy seeing 400V.  His 400V may be open circuit.  Without seeing a sample of his measurements and how he performs them, I don't know what he's really doing.

[Pirate88179]

@MarkE,

Quote from Pirate88179:

"I am even using some commercial bulbs in my lights, like the Lights of America 24 chip led bulbs and ...they are just fine with 400 volts at high freq.  My bedside table uses 2 of those bulbs and...I have been using it every night for many years and...the bulbs still work. (still using the original D cell battery also)".

Pirate's running a 120 volt AC LED bulb at 400 volts.

That is correct.  You can screw those bulbs into a light fixture and run them on 120, or place into my circuit and run them at around 400.  The lights of America have no electronics inside, so no need to modify.  Most of them are 27 chip leds and I have some that are 24.  Now, when I use the Cree 40 watt equiv. bulbs in the same circuit, I have already removed all of the electronics and am just using the leds.  I have hundreds and hundreds of hours on those LOA bulbs and all of them still work great.  Much brighter than lighting a gutted cfl.

Even running 2 bulbs of the LOA style led bulbs with 27 chips each (Like the one next to my bed) I am only drawing 150 mA's.

Bill