Search found 1461 matches

by dyarker
Wed Jul 26, 2017 7:03 am
Forum: General Discussion
Topic: What keeps me up late!
Replies: 48
Views: 6012

Re: What keeps me up late!

An alternate possibility on the envelope - You put the contents inside, and suspect it might be over weight. You don't want it to come back; so either you weigh it yourself, or take it to the Post Office. With the measured weight and postal chart the correct postage is lookedup. Then stamp, or stamp...
by dyarker
Wed Jul 19, 2017 8:34 am
Forum: General Discussion
Topic: Lightning rods...
Replies: 24
Views: 2387

Re: Lightning rods...

Try some more today.

https://en.wikipedia.org/wiki/Lightning_rod seems pretty informative

Is the rebar part of above construction? If yes then No, could break the concrete during a strike. If no then still no due to rust and iron has a higher resistance than copper, even without rust.

Cheers,
by dyarker
Tue Jul 18, 2017 2:58 pm
Forum: General Discussion
Topic: Lightning rods...
Replies: 24
Views: 2387

Re: Lightning rods...

No
Yes
Above, yes
Not burned home

(Longer answer wiped by internet.)
by dyarker
Tue Jul 18, 2017 7:50 am
Forum: General Discussion
Topic: TONE DECODER
Replies: 3
Views: 820

Re: TONE DECODER

Perhaps those are ABCD ? No. Coin tone is mix of 1700Hz and 2200Hz in the U.S.. Highest tone in high group of DTMF is 1633Hz. "ABCD", "#" and "*" were/are used for specialized functions in different systems. (i.e. the U.S. military system used A thru D for precedence dialing.) Still other tones wer...
by dyarker
Sat Jul 01, 2017 7:36 am
Forum: General Discussion
Topic: Drone communication/control
Replies: 5
Views: 844

Re: Drone communication/control

Next big industry will be how to disable them in flight, if they pose a threat!
Yeah, people get upset by the noise from a shotgun. When the paparazzi start using them there will be plenty that need bringing down!
by dyarker
Fri Jun 30, 2017 8:40 am
Forum: General Discussion
Topic: What keeps me up late!
Replies: 48
Views: 6012

Re: What keeps me up late!

Oh, never mind.
Bye,
by dyarker
Fri Jun 30, 2017 6:49 am
Forum: General Discussion
Topic: What keeps me up late!
Replies: 48
Views: 6012

Re: What keeps me up late!

If a right angle is defined as 100°, then a full circle would be 400°. It unavoidable. Or, make full circle 1000°, then right angle is 250°. A right angle is one quarter of a full circle. It is impossible to have both based on a multiple of 10. It is a sphere, can still be subdivided in the same 'un...
by dyarker
Thu Jun 29, 2017 8:09 am
Forum: General Discussion
Topic: What keeps me up late!
Replies: 48
Views: 6012

Re: What keeps me up late!

Externet, I heartily agree with the idea, but - If you mean a full circle is 100 metric degrees, then longitude would run from -50 to +50 with the fiftys being the same line. And latitude would run from -25 (South Pole) to +25 (North Pole). If you try to make full circle, longitude and latitude all ...
by dyarker
Wed Jun 07, 2017 12:42 pm
Forum: General Discussion
Topic: ASCII in to ASCII out converter
Replies: 4
Views: 1041

Re: ASCII in to ASCII out converter

Is a PC one end of this serial link? Instead adding a box in the middle; make the string translation programmatically in a program.
by dyarker
Fri Jun 02, 2017 7:08 am
Forum: General Discussion
Topic: Turns ratio on audio transformer...
Replies: 8
Views: 1595

Re: Turns ratio on audio transformer...

No math in electronics ? :? ? :? ? :? ?
That is called a big pile of blown fuses, fried resistors, and transistors with the magic white smoke let out; but not electronics :)
by dyarker
Wed May 31, 2017 1:26 pm
Forum: General Discussion
Topic: Turns ratio on audio transformer...
Replies: 8
Views: 1595

Re: Turns ratio on audio transformer...

For transformers spec'ed in impedence - turns ratio equals square root of (primary impedence divided by secondary impedence) so 1300 / 8 = 162.5 162.5^ .5 = 12.75 2V * 12.75 = 25.5V You need turns ratio 4 times higher, or impedence ratio 16 times higher. 21K Ohms : 8 Ohms ought to do (if current loa...
by dyarker
Thu Mar 23, 2017 8:49 am
Forum: General Discussion
Topic: looking for a digital Fahrenheit sensor
Replies: 13
Views: 2337

Re: looking for a digital Fahrenheit sensor

Checked at Digikey. For analog there are Fahrenheit choises (fewer than Celsius, but there). For digital there is no choise, just Celsius. Makes sense. In analog converting could mean two op-amps, some resistors and compensation capacitors. In digital it is bit of programming to convert to Fahrenhei...
by dyarker
Sat Feb 11, 2017 6:14 am
Forum: General Discussion
Topic: Edenpure Classic space heater...NOT LEVEL
Replies: 11
Views: 2336

Re: Edenpure Classic space heater...NOT LEVEL

http://www.pureenergystore.com/edenpure-classic-heater-parts/ Does anything on that page look familiar? The back of the PC board has a connection for a "germ lamp". That would be UV lamp, and air flow would be through the box. The heating is the 500W infrared tubes. Are the other ICs on the PCB iden...
by dyarker
Fri Feb 10, 2017 2:48 pm
Forum: General Discussion
Topic: Edenpure Classic space heater...NOT LEVEL
Replies: 11
Views: 2336

Re: Edenpure Classic space heater...NOT LEVEL

Infrared is a longer wavelength than visible light (frequency below red). Where red is the longest visible wavelength. Ultraviolet is a shorter wavelength than visible light (frequency above violet). Where violet is the shortest visible wavelength. (wavelength and frequency are inversely proportiona...
by dyarker
Wed Feb 08, 2017 4:24 pm
Forum: General Discussion
Topic: 9 volt Duracell Procell
Replies: 6
Views: 1655

Re: 9 volt Duracell Procell

Looked at spec sheets for Duracell, Energizer and Panasonic. Even on paper (well pdf by manufacturers) the Duracell wasn't rated to last as long. Note - the 20 hour rate for Energizer and Panasonic looked like around 26mA. So, your 50mA load is on the heavy side for a 9V battery. Ever consider six A...