Abstract: Surge protection for a data transmission line, typically a telephone line including two data signal conductors, incorporates a primary protector circuit for high voltage, high energy surges and a secondary protector circuit for low voltage surges. The primary protector circuit includes a normally non-conductive "breakdown" or "crowbar" device having a high breakdown voltage, a solid-state triac, or a thyristor, driven conductive by a surge exceeding its breakdown voltage; the crowbar device is connected from one or both conductors to ground. An inductance is connected in the circuit to extend the time in which the circuit reduces a surge to near zero voltage, and thus dissipates power from the surge. The second protector circuit includes at least one avalanche diode, Zener diode, or other threshold device in parallel with the primary protector circuit.

Abstract: An add-on device that modifies the operating characteristics (e.g., amplitude, frequency response, "sustain") of the output signal of an electromagnetic pickup for a stringed musical instrument, such as a guitar with steel strings; the modification device includes one or more transversely magnetized thin, flat permanent magnets. The signal modification device covers most or all of the top surface of an electromagnetic pickup. In one form the signal modification device comprises a thin, flat permanent magnet member formed of resin impregnated with particulate permanent magnet material and magnetized transversely to its thin dimension, either uniformly or in a predetermined pattern; in another form the device includes one or more discrete thin, flat permanent magnets for each instrument string, mounted on a base sheet that may also have permanent magnet characteristics or that may be non-magnetic.