I tack soldered this two transistor “Joule Thief” V boost circuit together using one of the 100 microhenry low resistance (0.7 ohm) chokes that I bought from Mouser. I wanted a V boost circuit that put heavy current demands on the choke. The schematic for this type of circuit is here. I made the following
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The Youtuber going by the name of Sanjev21 has read my comment about using the TN0702 low gate threshold MOSFET for a Joule Thief that will start and run below 0.6V. He replied that this has a Rds(on)of 4 ohms at 2 volts, which is “too high”. The problem is that he is using a
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I got an email from amzfx<at>email.com with a link to this picture. I thought it was cool enough to blog. I figured that most Nixie tubes are driven by high voltage transistors such as the MPSA42, which are only a few cents apiece. In this case, it looks like the tube is driven by ten
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I once had this blogged in my watsonseblog, but I haven’t blogged it here. I’m trying to charge this Maxwell ‘Boost Cap’ or ultracapacitor with a solar cell, but the problem is that this cap is so ginormous that it takes a very long time to charge when the solar cell is putting out 100
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I continued on with my experiments using the BD433 by building a Light Flasher. This flasher is a very old design which originally used germanium transistors. It also predates LEDs, so it used a standard #1850 miniature lamp or incandescent light bulb. Instead I used LEDs, so I had to allow a small current to
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I ordered some parts from Mouser, and along with them I ordered some BD433 and BD438 transistors. Belza uses the BD433 in some of his LED projects and as far as I can make out using google translate, Belza says the BD433 is supposed to do a very good job in a Joule Thief. The
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I came across this forum thread where the person asks how to find and equivalent transistor. First off I would like to say that if you substitute another transistor and it burns up in a few seconds, like it did in this case, then you should certainly consider that the circuit is bad in some
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I wanted to get some 100 microhenry chokes to experiment with, so I ordered a bunch from BG Micro. Also, I found they had some Steward 2B0686-100 EMI Suppression Filter, which once I cut through all the gobbledygook, came down to toroid cores. So I ordered a dozen or so of those. Then I found
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Well, I saw this way of emulating a coil in the Wikipedia entry for Joule Thief. I said to myself, this is really Mickey Mouse, and it would never withstand the scrutiny of an engineer or designer if they saw it. It’s just not the way a circuit should be designed. But I did it
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A picture of my Supercharged Joule Thiefs and some coils I wound. I noticed that the LED in the center has a big bubble in the lens. I got some LEDs with bubbles in them from a seller on eBay, and I had to send them back to get a refund. I think this must
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