Search found 1470 matches

by dyarker
Tue Jul 18, 2017 7:50 am
Forum: General Discussion
Topic: TONE DECODER
Replies: 3
Views: 900

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: 973

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: 6533

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: 6533

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: 6533

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: 1126

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: 1726

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: 1726

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: 2520

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: 2440

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: 2440

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: 1733

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...
by dyarker
Sun Jan 22, 2017 5:11 am
Forum: General Discussion
Topic: Looking for a Rotary Servo
Replies: 1
Views: 562

Re: Looking for a Rotary Servo

Anyplace that has parts for radio controlled models.

The mechanics look reletively simple. The PID calculation software, and software to drive the servo that is hard.

Good luck,
by dyarker
Tue Jan 10, 2017 12:09 pm
Forum: General Discussion
Topic: 120v to 4800 v transformer
Replies: 14
Views: 2706

Re: 120v to 4800 v transformer

1. He said in post 1 the 120V winding was 10mA.

2. For the amount of iron, 1.2W makes more sense than 48W.(see left side of photo in post 3)
by dyarker
Mon Jan 09, 2017 3:07 pm
Forum: General Discussion
Topic: looking for a led driver board
Replies: 19
Views: 3244

Re: looking for a led driver board

I'll believe you, but it isn't easy. Pulse frequeny? Peak current?