Search found 59 matches

by dtief
Tue Oct 14, 2008 3:14 pm
Forum: General Discussion
Topic: Cutting clean holes in enclosures
Replies: 25
Views: 5666

Roughly - how much did those panels cost?
by dtief
Thu Oct 09, 2008 5:08 pm
Forum: General Discussion
Topic: Question About Automobile Noise Cancellation Technology
Replies: 8
Views: 2469

On the idea of wearing headphones that block sound while driving - I can't say for sure in all states, but some do have laws against it. Primary reason is they want drivers to be able to hear emergency vehicle sirens, horns, etc.
by dtief
Thu Oct 09, 2008 2:27 pm
Forum: General Discussion
Topic: Question About Automobile Noise Cancellation Technology
Replies: 8
Views: 2469

Lower frequencies are easier to cancel than higher. Below 100Hz low. Here's a simplified version of acoustic noise cancellation: A microphone located so that it picks up the noise. Another located near your ears. A speaker is in the acoustic space. A DSP calculates the phase and amplitude of the noi...
by dtief
Wed Oct 08, 2008 7:33 pm
Forum: General Discussion
Topic: Magnetic contraptions on videos...
Replies: 1
Views: 981

I looked at a few. I've seen these things before. I have yet to see one that isn't either an outright scammer, or most of them, just someone who doesn't know what they are talking about. Mangleing terms & basic electronics concepts, misinterpreting things. I have yet to see one where the inventor ac...
by dtief
Wed Oct 08, 2008 7:18 pm
Forum: General Discussion
Topic: Computer PSU to 150W HAM PSU ??
Replies: 17
Views: 4090

Also, switchers don't like low load conditions, so you have to put a load resistor or other circuitry on the output that the regulator actually regulates. Generally, I am refering to pre ATX power supplies. The regulated output is usually the highest curent output. With older supplies it would be th...
by dtief
Sun Sep 28, 2008 7:14 pm
Forum: General Discussion
Topic: Two Nuts & Volts Projects That Don't Make Sense
Replies: 8
Views: 2573

One of the things I like about N&V is they have a range of projects - from simple / beginner to advanced. While it's unlikely that I'll own a Prius soon - 10K is the most I will pay for a car - If I did, I could handle pretty much any modification safely. Would I recommend it as beginner electronics...
by dtief
Sun Sep 28, 2008 6:53 pm
Forum: General Discussion
Topic: CATV signal level meter
Replies: 4
Views: 1717

Sometimes it seemed like the weather had an effect, but sometimes it doesn't I had a phone line problem like that once. I kept having to tell the phone company "you have to come during or immediatly after rain to see the problem". Eventually they did, & fixed it. But I digress... The connection has ...
by dtief
Thu Sep 25, 2008 7:37 pm
Forum: General Discussion
Topic: MSN
Replies: 15
Views: 4677

Not knowing your setup, this may or may not help. I put all sites I don't like in my router's firewall. Blocks them nicely, without bogging down the computer. I have several computers on the router & hubs, on a cable modem. I use it to conviniently block any advertising site (& dataminers, etc.) tha...
by dtief
Thu Sep 25, 2008 7:27 pm
Forum: General Discussion
Topic: CATV signal level meter
Replies: 4
Views: 1717

CATV signal level meter

Is there any affordable signal level meter analyzer for cable TV signals? Or schematic for whatever RF meter that would do the job? I'd like to be able to check the signal level on the coax from my cable modem. A short sequence: All's well. Intermittant internet connection - tech checks, level too h...
by dtief
Thu Sep 18, 2008 6:48 pm
Forum: General Discussion
Topic: Stringed Instrument Tuner, Ideas?
Replies: 30
Views: 6447

@ philba - It should be equal. When the string looks like it's not moving coresponds to when you hear the beat frequency drop to zero. - to clarify my previous post: Here is an example of the tachometer / strobe I was refering to: http://www.hotektech.com/Itlab1542B.htm Not to be confused with an au...
by dtief
Wed Sep 17, 2008 7:06 pm
Forum: General Discussion
Topic: Stringed Instrument Tuner, Ideas?
Replies: 30
Views: 6447

It sounds like he is using the LED as a strobe light. So it needs to go on / off fast. = square wave. The tuning accuracy is related to the frequency / pulse rate of the flashes. Very similar idea to strobe based tachometers.

Dave
by dtief
Wed Aug 20, 2008 6:29 pm
Forum: General Discussion
Topic: Real time clock interface / coding
Replies: 2
Views: 1086

Intel mode.
by dtief
Wed Aug 20, 2008 5:13 pm
Forum: General Discussion
Topic: First impressions of Digi-Key
Replies: 13
Views: 4776

I've used DigiKey since their catalog was printed on 2 sheets of newsprint paper. :shock:

They have one of the best website / component search on the web. Sometimes it is easier to pick / find a new part on thier page than the actual manufacturer's pages.
by dtief
Wed Aug 20, 2008 5:09 pm
Forum: General Discussion
Topic: Real time clock interface / coding
Replies: 2
Views: 1086

Real time clock interface / coding

Hi, I am working on interfacing a BQ3285EP real time clock IC to a micromint 80C52 processor. I have done a *lot* of projects with the 80C52 w/BASIC, all kinds of I/O. Here's the problem: I can verify that I can progam the control registers- I can tell because I can set the bits to activate the squa...