Blinking Telephone Light

[CW]

> Back in the old days, people just put a neon lamp across the
> phone line. It doesn't load the line unless it is ringing.
> When the ring voltage comes down the line, it normally
> exceeds 60-65 volts or so, and the lamp lights.  Simple.
> The Bell System had neon lamps mounted in little octagonal
> base fixtures that resembeled the tail light lens of a '57
> DeSoto.  
>
> Just a neon lamp like a NE 2 and a series resistor (About
> 100-120 K, IIRC) should work.  I guess they still have neon
> bulbs at Rat Shack.

Telco specs for analog/POTS lines:
Line impedance: 600ohms typical
Tip/Ring voltage: On Hook (hung up) 48-56 V DC
                  Off Hook (when talking) 6V approx
                  (Actually, it is 20ma current flow that counts here)
Ring Voltage: 90V @ 20 Hz AC

Use of the Radio Shack box is easiest on POTS lines...if you are trying it on a KSU, make sure you do this on ANALOG lines only...the digital circuits do NOT comply with the above obviously and will be proprietary with any system.
Teltone made some relays that were great for signaling on ringing AND offhook...
but they are out of production.

[farside1023]

If you can't find them at Radio Shack, try www.sandman.com in Chicago. All kinds of phone stuff.

>
> Use of the Radio Shack box is easiest on POTS lines...if you
> are trying it on a KSU, make sure you do this on ANALOG
> lines only...the digital circuits do NOT comply with the
> above obviously and will be proprietary with any system.
> Teltone made some relays that were great for signaling on
> ringing AND offhook...
> but they are out of production.
>

[CW]

> If you can't find them at Radio Shack, try www.sandman.com
> in Chicago. All kinds of phone stuff.
>

Amen!! Mike has PLENTY of neat stuff