Mike Chambers
May 3rd, 2008, 01:22 AM
thought you guys might enjoy this. a few days ago i found a little box with a bunch of spare electrical components, and after a few minutes of looking through it i saw a couple things that gave me a great idea!
basically i just built a little circuit that lets me have all kinds of fun with the telephone line. i'm surprised it worked, i don't have much experience with making circuits but it is pretty simple really.
i drew this schematic if you want to make it... it's bad i know. i did it in ms paint.
http://rubbermallet.org/phone_fun_schematic.gif
as you can see, it's you don't need much:
- a transformer (doesn't need to be exactly 1k-ohm. it should be fine if its anywhere from like 600 to 1200 or so. the important part is making sure the wire coil ratio is equal on both sides, 1:1 and make sure it's an 8-ohm seconday tap)
- a 9VDC power source (you'll want at least 600 mA or so)
- a switch
- two 150 ohm resistors.
you'll also have to butcher a phone cord with an RJ11 jack on it, and you'll need two cables with standard 1/8-inch headphone jacks on one end of each. (you could take them from a couple broken or crappy headphones if you want)...... btw, the transformer i used is item #273-1380 from radio shack.
what it'll do if you haven't figured it out yet, is let you run ANY audio you want directly into the phone line from a sound card or any other audio source with a headphone out or line-out. PLUS if you flip the switch on, it can record all the audio going over the line with your sound card's mic-in :)
you might have to run the mic-in lead through a pre-amp first. even with mic gain turned on in the sound card, you could barely hear it until i did that. oh and make SURE you put those resistors on, or you'll get a nice loud feedback loop!
so basically i can think of three real uses for it. the first one (and this is awesome) is i've been using a regular phone for making skype calls by plugging the RJ11 from the circuit right into an old phone! :cool::cool::cool:
the other is plugging the RJ11 right into the phone jack on the wall and screwing with telemarketers. after you answer and they say they're with so-and-so and want all your money, just say "i'd be happy to talk with you, i'm sorry can i put you on hold for a moment?"
then you have a your winamp playlist set up with a bunch of terrible elevator music and you could have a synthesized computer voice interrupt now and then and say "we appreciate you holding. the estimated wait time is currently 43 minutes" or something like that. see how long it takes them to hang up.
third use would be recording phone convos to a sound file if you wanted to for something.
a couple notes... the 9 VDC power source is generally only needed if you are using a regular corded phone. if you use a cordless phone or any other one with it's own power source it does not need this.
the way the phone line works is they send a ~9 VDC signal through the line when the line is in use. if you don't do that, a standard corded phone won't do a thing when you try to use it.
come to think of it, you might want to put a 2-way switch there that lets you bypass the battery because you for sure don't want the telco's power on the line going through the battery... unless you like explosions.
have fun!
basically i just built a little circuit that lets me have all kinds of fun with the telephone line. i'm surprised it worked, i don't have much experience with making circuits but it is pretty simple really.
i drew this schematic if you want to make it... it's bad i know. i did it in ms paint.
http://rubbermallet.org/phone_fun_schematic.gif
as you can see, it's you don't need much:
- a transformer (doesn't need to be exactly 1k-ohm. it should be fine if its anywhere from like 600 to 1200 or so. the important part is making sure the wire coil ratio is equal on both sides, 1:1 and make sure it's an 8-ohm seconday tap)
- a 9VDC power source (you'll want at least 600 mA or so)
- a switch
- two 150 ohm resistors.
you'll also have to butcher a phone cord with an RJ11 jack on it, and you'll need two cables with standard 1/8-inch headphone jacks on one end of each. (you could take them from a couple broken or crappy headphones if you want)...... btw, the transformer i used is item #273-1380 from radio shack.
what it'll do if you haven't figured it out yet, is let you run ANY audio you want directly into the phone line from a sound card or any other audio source with a headphone out or line-out. PLUS if you flip the switch on, it can record all the audio going over the line with your sound card's mic-in :)
you might have to run the mic-in lead through a pre-amp first. even with mic gain turned on in the sound card, you could barely hear it until i did that. oh and make SURE you put those resistors on, or you'll get a nice loud feedback loop!
so basically i can think of three real uses for it. the first one (and this is awesome) is i've been using a regular phone for making skype calls by plugging the RJ11 from the circuit right into an old phone! :cool::cool::cool:
the other is plugging the RJ11 right into the phone jack on the wall and screwing with telemarketers. after you answer and they say they're with so-and-so and want all your money, just say "i'd be happy to talk with you, i'm sorry can i put you on hold for a moment?"
then you have a your winamp playlist set up with a bunch of terrible elevator music and you could have a synthesized computer voice interrupt now and then and say "we appreciate you holding. the estimated wait time is currently 43 minutes" or something like that. see how long it takes them to hang up.
third use would be recording phone convos to a sound file if you wanted to for something.
a couple notes... the 9 VDC power source is generally only needed if you are using a regular corded phone. if you use a cordless phone or any other one with it's own power source it does not need this.
the way the phone line works is they send a ~9 VDC signal through the line when the line is in use. if you don't do that, a standard corded phone won't do a thing when you try to use it.
come to think of it, you might want to put a 2-way switch there that lets you bypass the battery because you for sure don't want the telco's power on the line going through the battery... unless you like explosions.
have fun!