With this system you can disconnect phone lines in case of need for protection. The circuit is from a 1989 documentation working only with analog lines.
With an output power of 1.5 W under a 12 V supply, this circuit makes use of transistors that are...
I got this circuit from Hands-On Electronics, 1988. The American magazine no longer exists, but...
This circuit is from the Motorola Linear Databook of 1990. The values of the components depend on the...