MYVALK

i need to build, and be shown how to hook up, a remote phone bell, so i can hear the phone when im outside of my office.
any ideas?
thanx in advance.

wow... bigger than i thought hahaha

Leftyretro

Just use a normal phone hooked up outside your office?

__________________
Measurement changes behavior

crutschow

Radio Shack sells a remote ringer at http://www.radioshack.com/product/in...entPage=search that should do just what you want.

MYVALK

thats it . thanx.

MYVALK

but.. if i wanted to build my own, what would it entail?

blueroomelectronics

You've got to be careful what you connect to the phone lines. It's better if you buy such a device and most likely cheaper than the parts you'll need.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

crutschow

Bill is right. Why reinvent the wheel?

The phone ring in the U.S. is a 20Hz, 75VAC signal which is riding on -48V DC. You need to detect the AC (without drawing any significant DC current) and convert it into a higher frequency audible signal (20Hz being pretty well inaudible). The circuit to detect this must be isolated from ground. The equivalent load for 1 ringer is defined to be an 8uF cap in series with 6930 ohms. It's good practice not to exceed that load when connecting to the phone line.

I made one many years ago using a unijunction transistor oscillator powered from the ring signal to generate high frequency pulses (a kHz or so) which drove a small speaker. Made kind of a ratty sound, but you knew when the phone was ringing.

Still want to do it?

Super_voip

8uF, here it's 2uF

MYVALK

ok guys, ill take your advice and radio shack it.

thanx again.