How to build a black box

Category: Tutorial


<< Buy This Book on Amazon >>

346 views since 2007-05-18, updated at 2007-05-27. Bookmark this: How to build a black box

Description


How to build a black box?

I found this tutorial quite a long time ago and I don't know if it still works. Nevertheless , it might be interresting to read, you might even learn something from it! I would have gladly given credit to it's author but won't since I have no idea who he is. So here is his tutorial that remained unchanged ( I hope!):

A BLACK BOX
is a device that is hooked up to your phone that fixes your phone so that when you get a call, the caller doesn't get charged for the call. This is good for calls up to 1/2 hour, after 1/2 hour the phone Co. gets suspicious, and then you can guess what happens.

What this little beauty does is keep the line voltage from dropping to 10v when you answer your fone. The line is instead kept at 36v and it will make the fone think that it is still ringing while your talking. The reason for the 1/2 hour time limit is that the
phone CO. thinks that something is wrong after 1/2 an hour of ringing.

All parts are available at Radio Shack. Using the least possible parts and arangement, the cost is $0.98 !!!! And that is parts for two of them! Talk about a deal! If you want to splurge then you can get a small PC board, and a switch. There are two
schematics for this box, one is for most normal fones. The second one is
for fones that don't work with the first. It was made for use with a Bell
Trimline touch tone fone.

** Schematic 1 for most fones **
** LED ON: BOX ON **

FROM >--------------------GREEN-> TO
LINE >--! 1.8k LED !---RED--> FONE
!--///--!>--!
! !
------>/<-------
SPST



Parts: 1 1.8k 1/2 watt resistor
1 1.5v LED
1 SPST switch

You may just have two wires which you connect together for the switch.


** Schematic 2 for all fones **
** LED ON: BOX OFF **

FROM >---------------GREEN-> TO
LINE >------- ---RED--> FONE
! LED !
-->/<--!>--
! !
---///---
1.8k
�Parts: 1 2 watt resistor
1 1.5v LED
1 DPST switch


Here is the PC board layout that I recommend using. It is neat and is very easy to hook up.

Schematic #1 Schematic #2

************** ****************
* * * ------- *
* ----- * * ! ! *
* ! ! * * ! *
* RESISTOR ! * * ! ! ! *
* ! ! * * ! ! / *
* -------- ! * * ! ! *
* ! ! * * ! ! / *
* --SWITCH-- * * ! ! *
* ! ! * * ! ! / *
L * ! ! * F L * ! ! ! * F
I>RED- -RED>O I>RED- ---RED>O
N>-----GREEN---->N N>-----GREEN------>N
E * h * E E * * E
************** ****************

Once you have hooked up all the parts, you must figure out what set of wires go to the line and which go to the fone. This is because of the fact that LED's must be put in, in a certain direction. Depending on which way you put the LED is what controls what wires are for the line

Download this book from Usenet
DOWNLOAD Free register and download UseNet downloader, then you can free download from UseNet.

Free Download "How to build a black box" from Usenet!

Buy this book from amazon


Disclaimer:
Contents of this page are indexed from the Internet. All actions are under your responsability. Email us to report illegal contents or external links and we'll remove them immediately.

Search More...

How to build a black box

Search free ebooks in ebookee.com!


Links

Free Trade Magazine Subscriptions & Technical Document Downloads

Search and Buy
<< Search and Buy This Book on Amazon >>

Download this book from Usenet
DOWNLOAD How to download:
Free register to download UseNet downloader and install, then search book title and start downloading. You can DOWNLOAD 150GB for free! Register and Download NOW!

Free Download "How to build a black box" from Usenet!

Download Link 2


No download links here
Please check the description for download links if any or do a search to find alternative books.

Can't Download?
Please search mirrors if you can't find download links for "How to build a black box" in "Description" and someone else may update the links. Check the comments when back to find any updates.

Search Mirrors
Maybe some mirror pages will be helpful, search this book at top of this page or click here to find more info.


Related Books


Books related to "How to build a black box":


Comments


No comments for "How to build a black box".

Usenet Binaries anonym mit DSL Speed downloaden inkl. gratis Software

    Add Your Comments

    1. Download links and password may be in the description section, read description carefully!
    2. Do a search to find mirrors if no download links or dead links.

    required

    required, hidden

    need login

    required

    More Categories

    We Recommend

    Email Subscribe

    Enter your email address:

    Delivered by FeedBurner

    Feed & Bookmark

    • Add to Google Reader or Homepage

    Sponsored Links

    Back to Top