Search found 1746 matches

by dyarker
Mon Apr 12, 2004 9:45 pm
Forum: General Discussion
Topic: 1 Bit ALU
Replies: 3
Views: 2238

Re: 1 Bit ALU

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by jwax: Curious Turbo, what is a 1 bit ALU at the uni? :D :roll: <p>More seriously, 1 bit addition is Exclusive OR. 0b + 0b = 0b 1b + 0b = 1b 0b + 1b = 1b 1b + 1b = 0b (10b withou...
by dyarker
Mon Apr 12, 2004 6:09 am
Forum: General Discussion
Topic: 'gold' color /silver color on transistor EBC legs?
Replies: 9
Views: 3924

Re: 'gold' color /silver color on transistor EBC legs?

TO-5, round steel can 'bout 3/8" diameter 5/16" high with a maybe brass ring around the bottom with a tab to show emiter, 3 wire leads 2" or 3" long made of steel because they supported the transistor off the board or terminal strips. RF and switching types tended to be gold plat...
by dyarker
Sun Apr 11, 2004 9:33 pm
Forum: General Discussion
Topic: 'gold' color /silver color on transistor EBC legs?
Replies: 9
Views: 3924

Re: 'gold' color /silver color on transistor EBC legs?

Used to see TO-5s with steel leads plated copper/tin or gold.
by dyarker
Thu Apr 08, 2004 6:07 am
Forum: General Discussion
Topic: Need help with a simple transistor circuit
Replies: 8
Views: 3432

Re: Need help with a simple transistor circuit

Where is the thermistor already in use?<p>"Tapping-in" will probably upset operation of existing circuit. And, if the existing circuit isn't isolated from AC mains it could upset your circuitry ... permanently.<p>So, more detail please. Then you'll get lots of suggestions.<p>Cheers,
by dyarker
Thu Apr 08, 2004 5:51 am
Forum: General Discussion
Topic: midi player
Replies: 15
Views: 6939

Re: midi player

Going the other way, a Yamaha keyboard. If you mean large pocket sized, I don't think such a thing exists.<p>Cheers,
by dyarker
Thu Apr 08, 2004 5:39 am
Forum: General Discussion
Topic: Need bezel for LCD dispalys
Replies: 3
Views: 2227

Re: Need bezel for LCD dispalys

Digikey? Jameco?<p>[ April 08, 2004: Message edited by: Dale Y ]</p>
by dyarker
Thu Apr 08, 2004 2:18 am
Forum: General Discussion
Topic: Transmitter Power in dBm
Replies: 9
Views: 4268

Re: Transmitter Power in dBm

For dBm the "m" is for milliWatt and 0dBm = 1mW. Relative numbers like loss or gain are "dB".<p>A perfect monopole antenna is defined as a gain of 0dB, and emits the signal equally in all directions. The shape of equal signal strengths is a sphere.<p>With a real antenna like a qu...
by dyarker
Sun Apr 04, 2004 12:48 am
Forum: General Discussion
Topic: Audio Frequency Counter Recommendation
Replies: 14
Views: 6798

Re: Audio Frequency Counter Recommendation

How about a program that uses a PC's sound card. There must be be a freeware/shareware/demo on the web somewhere.<p>Cheers,
by dyarker
Fri Apr 02, 2004 5:18 pm
Forum: Robotics
Topic: dedicated motor controller protocols
Replies: 8
Views: 6189

Re: dedicated motor controller protocols

oops, when I said "RS-485", I should have said "I2C". A lot of PICs and other microcontrollers have I2C built in. A very popular standard!
by dyarker
Thu Apr 01, 2004 12:12 am
Forum: Robotics
Topic: dedicated motor controller protocols
Replies: 8
Views: 6189

Re: dedicated motor controller protocols

I think L. Daniel Rosa means a protocol between the controllers he's building, and a PC or master microcontroller. As Harold said, the signal needed by a servo is already specified. Stepper motor signals will depend on motor type.<p>For PC to controller protocol I would guess RS-485 as most popular....
by dyarker
Wed Mar 31, 2004 4:12 am
Forum: General Discussion
Topic: Life on Mars???
Replies: 5
Views: 2721

Re: Life on Mars???

April Fool!!!! I think.<p>April issue, memory problems, etc.
by dyarker
Wed Mar 31, 2004 2:03 am
Forum: General Discussion
Topic: 433mhz data reciever
Replies: 3
Views: 2371

Re: 433mhz data reciever

The unit working when your hand is near/on it is the clue. It wants a grounded common. And if TX antennas are vertical, keep RX antenna vertical.<p>Cheers,
by dyarker
Tue Mar 30, 2004 7:16 pm
Forum: General Discussion
Topic: PWM or PDM ?
Replies: 2
Views: 1467

Re: PWM or PDM ?

I think PWM and PDM are the same.<p>With just ON and OFF, there are only two variables, ratio of ON to OFF and frequency. PWM has a fixed frequency and varies the ratio. PFM has a fixed ON time and varies the frequency to change ratio.<p>Did the Forrest Mims List have PFM (Pulse Frequency Modulation...
by dyarker
Mon Mar 29, 2004 12:52 am
Forum: General Discussion
Topic: Best way to regulate a high current PS?
Replies: 8
Views: 3477

Re: Best way to regulate a high current PS?

Stay with the Variac.<p>With any kind of AC duty cycle controller into filtered DC, the output voltage will always try to approach peak at anything more than 45% (with current pulses getting narrower and higher). At less than 45% the output voltage will adjust, but will vary depending on load (bad r...
by dyarker
Wed Mar 24, 2004 8:23 pm
Forum: General Discussion
Topic: How a Power inverter works?
Replies: 9
Views: 3896

Re: How a Power inverter works?

250V at 50A ... We have an UPS at work about that size. It is about the size of the large refrigerator! The battery box about the size of 3 refrigerators. The 12V batteries are in series.<p>Can I ask a question? What do you want such a beast for? For variable speed of a BIG motor? I would suggest SC...