Search found 1797 matches

by Externet
Tue Jun 18, 2002 8:37 pm
Forum: General Discussion
Topic: Audio Spotlight
Replies: 1
Views: 1415

Re: Audio Spotlight

Hello Abu. You will get better results at higher frequencies (over 500 Hz ¿?), the bass range will reach, but spreads too soon. Get a solid (not mesh) parabolic reflector from a discarded satellite antenna and position the speaker cone center exactly at focus aiming towards the parabola. The smaller...
by Externet
Tue Jun 18, 2002 11:37 am
Forum: General Discussion
Topic: Hey Dacflyer... bib on !
Replies: 0
Views: 983

Hey Dacflyer... bib on !

Hello.
Visit this:<p>http://www.neontrim.com/<p>Enjoy,
Miguel
by Externet
Tue Jun 18, 2002 8:08 am
Forum: General Discussion
Topic: "Phantom power 4 mic. "
Replies: 3
Views: 986

Re: "Phantom power 4 mic. "

Hello Dacflyer.<p>The electret condenser microphones take a little power via the same lead the audio exits. Isolating the audio and power is done with a capacitor and a resistor.
Here is a great place to dig deeper :<p>http://www.hut.fi/Misc/Electronics/circ ... ering.html<p>Miguel
by Externet
Sat Jun 08, 2002 12:54 pm
Forum: General Discussion
Topic: 5 AH NiCd single cell charger
Replies: 6
Views: 4338

Re: 5 AH NiCd single cell charger

Hello. The simplest way is to use a 22 ohm / 10 Watt resistor in series with any 500mA capable 12 V source as your car cigarette lighter. A 12V/~6W automotive lamp bulb should work too. This will yield about 500mA charge. If the battery gets hot, increase the resistor value to 33 ohm or more until d...
by Externet
Sat Jun 08, 2002 12:33 pm
Forum: General Discussion
Topic: LED operating point
Replies: 5
Views: 1391

Re: LED operating point

Hello. Check its data sheet. If you do not have it... If you mean optimum as maximum life, drive it with less than 20 mA. The voltage across it will be around 3.8 V, depending on the manufacturer or composition. If you mean maximum brightness, you could push it up to 40mA. You cannot have both "opti...
by Externet
Sun May 26, 2002 5:15 pm
Forum: General Discussion
Topic: LCD Display Connection?
Replies: 2
Views: 840

Re: LCD Display Connection?

Hello Dave. It is called zebra connector, is made of multiple conductive rubber strands, very close to each other, and provides resiliency, soft contact and shock absorption between conductive glass traces to the pcb traces. The alignmmennt is not critical as one or more of the strands will be able ...
by Externet
Sun May 19, 2002 8:15 pm
Forum: General Discussion
Topic: Another ROV Question -Tilt
Replies: 7
Views: 1883

Re: Another ROV Question -Tilt

Agree, mercury. If placed inside a sealed concave dish, maybe 1" Ø with one single central contact at the bottom and peripheric contacts as many as resolution wanted (maybe 8 or every 45 degrees) will yield a signal at the heading down one. Problem: will misread under acceleration.<p>An upside-down ...
by Externet
Sat May 18, 2002 7:57 pm
Forum: General Discussion
Topic: Do Compasess work underwater ?
Replies: 3
Views: 1404

Re: Do Compasess work underwater ?

Yes. They work. Wrist worn or attached to a hose.<p>Miguel
Scuba diver.
by Externet
Thu May 09, 2002 2:07 pm
Forum: General Discussion
Topic: GPS Devices To Track Cars
Replies: 8
Views: 2137

Re: GPS Devices To Track Cars

Hi EVA.<p>I am after the same on the same cheap budget for my classic car... My intention is to securely hide a low powered ~1W? 2m amateur radio transmitter behind the dashboard or somewhere, that would transmit simplex 2 second bursts every minute (sort of a beacon) at 144.000 MHz whenever there i...
by Externet
Wed May 01, 2002 7:44 pm
Forum: General Discussion
Topic: Prepaid Cell Phones
Replies: 2
Views: 1096

Re: Prepaid Cell Phones

Hi Buford.<p>The real good stuff is in Europe. You buy a card at a corner store with as many minutes as you choose, with the service provider you want.<p>Stick it inside your OWN portable telephone, and you are talking. No contracts, no ties, no monthly fees, no credit references, no nothing.<p>They...
by Externet
Tue Apr 16, 2002 6:03 pm
Forum: General Discussion
Topic: Battery-Powered Radio Transmitter?
Replies: 4
Views: 1485

Re: Battery-Powered Radio Transmitter?

Hi Thomas. Two days ago I bought a portable CD player with built-in transmitter for FM stereo reception in my classic car radio. The whole thing was $55 at Wherehouse, that place they sell music CD's. It transmits well, but skips. I do not know if MY unit is defective, I will have to return it/excha...
by Externet
Mon Apr 15, 2002 8:59 am
Forum: General Discussion
Topic: UAV project
Replies: 7
Views: 2584

Re: UAV project

Hi Bill.<p>I suggest you stay very away of such projects.
It's nice as a thought, but not beyond.<p>Miguel
by Externet
Sat Apr 06, 2002 7:40 pm
Forum: General Discussion
Topic: Cellular Antenna Lights - I'm confused
Replies: 8
Views: 2969

Re: Cellular Antenna Lights - I'm confused

Hi !<p>The leds turn on when the antenna transmits, not with reception microvolts as mentioned above...<p>One miliwatt could be enough to emit light from a very efficient led; and a portable phone outputs about a watt to antenna, so there is enough energy to tap from. I believe the portable telephon...
by Externet
Tue Mar 26, 2002 10:11 am
Forum: General Discussion
Topic: 12v DC - 9v DC
Replies: 5
Views: 2135

Re: 12v DC - 9v DC

Hi !<p>A 78M09 voltage regulator will do it.<p>Miguel