Been a while since I've read here. I need sources for various simple projects

I've got a new camcorder, the old Cannon bit the dust. Unfortunately the 6V gel-cell battery that I used to power it won't power my new camcorder because that one needs 8.4V. So, what I need (I think) is a DC-DC converter that takes down to 5.5V and bumps it up to a nice clean

8.4VDC @ 1A (the rating on the A/C adapter that came with the camera). Is this something that's possible?

Next up, I want to build a nice NiMH charging circuit that uses temperature to control the charging cycle. I know it's a bit more complicated than that, but does anyone have some good sources I can start learning at? I've been using the cheap timer chargers but I find that typically the AA cells are too damaged to be reliable after only 10-20 chargning cycles.

Next one's more difficult, I think. I want to make some exhaust temperature pyrometers. I bought some thermocouple wire, and want to use stainless steel tubing to make the actual probe with. I'll weld one end of a short length of tube closed with my TIG, and I'll use a compression fitting with a 1/16" NPT pipe to actually install the probe into the exaust tube at the head. Do I need to weld the ends of the thermocouple wire together to establish a junction? Or will twisting the ends together work? Also, I'd like to pot it in something to electrically insulate the wire from the housing, what can I use? I'll be making half a dozen of these so that I can do cylinder to cylinder comparisons.

Any suggestions, sources, and/or ideas would ge greatly appreciated!

JazzMan

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Reply to
JazzMan
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This is better suited to news:sci.electronics.basics

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

Start with companies like

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and
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find parts that meet your needs and request a few samples.
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has some good parts for these purposes too.

Reply to
James Sweet

Thanks, had no idea that group even existed!

JazzMan

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********************************************************** Please reply to jsavage"at"airmail.net. Curse those darned bulk e-mailers! ********************************************************** "Rats and roaches live by competition under the laws of supply and demand. It is the privilege of human beings to live under the laws of justice and mercy." - Wendell Berry **********************************************************
Reply to
JazzMan

In your application I'd suggest welding.

There's nothing wrong with twisting the wires together from a theoretical point of view but in practical application twisting might not work. Oxidation or vibration could lead to loss of electrical continuity. Plus a twisted junction tends to be worse in terms of thermal properties with too much mass and length that can add errors to your measurement. Also cold working some thermoelements shifts their calibration.

Bill

Reply to
Bill

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