T&L Publications

In general what you describe is illegal in the US. You may not deploy a device that interferes with radio transmissions.

Most inexpensive digital thermometers are accurate to about 1C (~2F), so the results you are getting for several different thermometers is about right. Generally, that is sufficiently accurate, even for laboratory work. (An expensive mercury filled lab thermometer is typcially accurate to about 0.5C...

Ya, 60% humidity is anything but low. The page is probably referring to something more like January in the Midwest where inside humidity might be as low as 15%. I take it this is the basic jFET-9V battery-LED setup for detecting electrostatic fields? You might get better sensitivity if you remember ...

Mr. Al The issue arises when two (or more) measurements have widely different precisions (by definition accuracy is basically always unknown). Working with the given example of a precisely known bucket count but a bucket of unknown accuracy and precision. And, the bucket's precision may also be furt...

"All those significant digits (67,435 gallons total) are totally worthless." Not quite. Though you are correct that a formula can not, in general, give an answer that is more precise than the least precise value in it**, some level of extra precision, even some that is beyond what is belie...

Have you considered replacing the lock washer with say a dab of locktight (or clear fingernail polish, or superglue or ...). Or, go old school and simply bend the nut slightly, or dimple it with a punch. Or, replace the star washer with a standard split ring washer. The split ring should work just a...

Sounds like you are talking about the ignition circuit for a gas water heater, or some such similar appliance. The circuit has to turn on the glow igniter, verify it is on, turn on the gas, verify the flame lit, recycle if the flame signal is lost, etc. and do appropriate things when something doesn...

Another place to check would be at your local Fedex-Kinkos (or other print shop). They mostly use laser printers and they definitely have transparency material. (Regular inkjet transparencies melt in a laser printer.) Heck, you can probably submit your artwork online and get a single copy or two on ...

"650 total watts out of 5 speaker modules" How was the power actually spec'd? It should be quoted as either RMS (reasonably accurate measure of output) and not "peak" or IHF (both are basically meaningless). And, it should spec that all channels are driven simultaneously and quot...

Or, debounce with just a series resistor followed by a cap to ground, it's a low pass filter. A 555 will take what two resistors and a cap and the 555 and ...

Figure something like a 10MFD cap and a 10K resistor, RC~0.1S (~10Hz).

my $0.02 Acetone is worth a shot. But, DO NOT HEAT THE ACETONE! Acetone is a gigantic fire hazard, much worse than say gasoline. A hot electric burner is enough to ignite acetone vapors. Acetone has a pretty low boiling point so even mild warming will generate a large amount of combustable vapor. An...

Like Robert said. For example, a 100W 120 VAC (RMS) incandescent light bulb has a resistance of about 140 ohms at its operting temperture. At room temperature the resistance is more like 10 ohms. (The filament of an incandescent light operates at about 4500F.) Light bulbs and heaters are, in a sense...

Peterlonz I don't think 20,000 hours is nearly enough. A single year at 100% duty, which is nothing for a bus strip, is 8760 hours. 20K hours is less than three years. Figure the lifetime of a generic bus strip (ignoring any surge protection capability) is probably 10+ years that means the LED will ...

Looking at the circuit the MrAl posted and the rest of this thread, reminds that a few years back a friend that works for "Ginormous Gov't Military Contractor Of High End Electronics" says all the ubiquitous 120 VAC bus strips with the NE-2 type power indicator lights were being replaced i...

Besides the N&V article there are a couple other pretty simple ways to do a shooting chronometer (a device to measure the time of flight between to detectors). All you really need is a pair of phototransistors (RadioShack has suitable ones for a buck or so) and a laptop with a sound card. There ...