Search found 1783 matches

by Externet
Tue Mar 26, 2002 10:11 am
Forum: General Discussion
Topic: 12v DC - 9v DC
Replies: 5
Views: 1924

Re: 12v DC - 9v DC

Hi !<p>A 78M09 voltage regulator will do it.<p>Miguel
by Externet
Tue Mar 19, 2002 5:27 pm
Forum: General Discussion
Topic: Differential to referenced audio drive
Replies: 1
Views: 1181

Re: Differential to referenced audio drive

Hi Ian. That is "balanced to unbalanced", in RF terms, would be a balun transformer. In audio stereo terms, it is still two -audio- transformers with one lead of each secondary tied together as common for the headphones. I do not know which IC you have in mind, but the data sheet should tell you if ...
by Externet
Mon Mar 18, 2002 12:10 pm
Forum: General Discussion
Topic: cell phone antenna light thingies
Replies: 13
Views: 4921

Re: cell phone antenna light thingies

Hi Dacflyer.<p>I will try to guess this one... As they are LED's, I suppose their leads are cut precisely at ¼ wavelenght and function as a dipole antenna. The high efficiency in new led's helps too. Try the highest efficiency LED you can find, the one you make light with the least current, and clip...
by Externet
Mon Mar 11, 2002 12:25 pm
Forum: General Discussion
Topic: cell phone antenna light thingies
Replies: 13
Views: 4921

Re: cell phone antenna light thingies

Hi !
I would say they are neon or other gases bulbs, turning on by the RF field.<p>You like lights ? Clip the leads off some neon bulbs an put them on top of a useless compact disk, all this on top of a cup with some water; in your microwave oven...<p>Miguel
by Externet
Wed Mar 06, 2002 2:08 pm
Forum: General Discussion
Topic: How to 6VDC to 12VDC (antique car)
Replies: 11
Views: 2933

Re: How to 6VDC to 12VDC (antique car)

Hello .<p>Here you have it :<p>http://www.jcwhitney.com/product.jhtml? ... 26&BQ=jcw2<p>Enjoy your radio,<p>Miguel
'62 Caddy
by Externet
Tue Mar 05, 2002 3:38 pm
Forum: General Discussion
Topic: inverter rfi problems
Replies: 4
Views: 1399

Re: inverter rfi problems

Hello.<p>The interfering noise can reach your amateur radio equipment via the house power lines or via antenna; or both. You must find first the offending path to tackle the problem. Try operating the HF radio with an automobile battery with no connections at all to mains. If you still get the noise...
by Externet
Wed Feb 27, 2002 10:27 pm
Forum: General Discussion
Topic: Faxphone B70
Replies: 2
Views: 1104

Re: Faxphone B70

Hi !<p>I have been digging for the precise information, but cannot find my fax service manual I purchased from Canon. I have the invoice with the right phone numbers somewhere. Just remember it was very easy: Call Canon asking for the right phone number to order service manuals. Should work for you ...
by Externet
Mon Feb 25, 2002 4:24 pm
Forum: General Discussion
Topic: Object tracking
Replies: 2
Views: 1295

Re: Object tracking

Hello.<p>As expressed above, some extra information could help. If the location of a person in a building is reduced to which room instead of what part of a room (resolution) there is a way that comes to mind, BUT, every person must wear some sort of identification to discern who and where. That cou...
by Externet
Mon Feb 18, 2002 9:09 pm
Forum: General Discussion
Topic: engine control Unit ECU
Replies: 7
Views: 1938

Re: engine control Unit ECU

Hi Mark.<p>It is a big can of worms, spiders and bugs.<p>Not to answer your question but for you to sense how this ball game is played, visit:<p>http://www.starrperformance.com.au/efilivev5/index.htm<p>Enjoy,<p>Miguel
by Externet
Wed Feb 13, 2002 12:09 pm
Forum: General Discussion
Topic: PC Based Scope?
Replies: 6
Views: 1763

Re: PC Based Scope?

Hi Brettn.<p>>>>>>>>>>> does anyone know of a circuit that I can use to probe electronics that will protect my sound card from too high of a voltage or too much amperage?<<<<<<<<<<p>For this, you may use 1n4007 diodes pairs head to toes; only one will clip signals at 0.7Vpp; if you use two in series...
by Externet
Tue Feb 12, 2002 5:36 pm
Forum: General Discussion
Topic: PC Based Scope?
Replies: 6
Views: 1763

Re: PC Based Scope?

Hi OKjello.<p>Here it is:<p>http://polly.phys.msu.su/~zeld/oscill.html<p>The good thing is it really works. Enjoy,<p>Miguel
by Externet
Tue Feb 05, 2002 9:29 pm
Forum: General Discussion
Topic: 5V to 3.3V
Replies: 4
Views: 1294

Re: 5V to 3.3V

Hi Matthew.<p>Almost any defunct computer motherboard will be a glad donor for such low dropout voltage regulator.
They are usually TO-220 with a small heatsink, and can supply up to 3 Amperes.<p>Computer power supplies yield 5V, but many chips on the mainboards run on 3.3V.<p>Miguel
by Externet
Fri Feb 01, 2002 2:09 pm
Forum: General Discussion
Topic: Telephone system question
Replies: 4
Views: 1376

Re: Telephone system question

Hi Russ.<p>.>>>>> Can someone tell me how the central office knows the phone is off hook and should stop ringing? How much current can I draw from the line? <<<<<<<<<p> In the central office (CO), the 48 Volt battery is fed to your line pair trough sensitive relay coils in SERIES with it.<p>With you...