Surge protector

Abstract: Surge protector components are enclosed within a housing similar in size and shape to that of a "plug-in" circuit breaker. The surge protector enclosure is provided with "stabs" for plugging in to the loadcenter bus, thus connecting the protector line contact solidly to the service conductors. The breaker enclosure is large enough to provide for generously sized surge-protecting components, and the outside case is usually made of phenolic, which can confine the energy of even relatively large surges. Furthermore, the loadside terminal will accept a good sized wire, such as #10 or even #8, which can solidly ground the protective element to the system grounding bus. In most small systems, the loadcenter acts as service equipment, and contains the ground/neutral bus. Instead of the unnecessary breaker handle, there may be a holder for a renewable fuse to limit the follow current after a heavy strike and even a neon lamp to indicate that the surge protective element has been made inoperative by lightning. Replacing the protector is as easy as replacing a breaker. Manufacturers' distributors will presumably stock the surge protectors as they now stock replacement breakers.

Abstract: A surge protection device for low level electronic systems and especially conventional roadway traffic monitoring equipment connected to embedded roadway sensors, which includes, for each sensor, first and second stage common mode and normal mode surge arrestor circuits and which stages are connected by a common mode choke in series with the sensor circuit and monitoring equipment. The first and second stage surge arrestor circuits and choke are preferably mounted on surge arrestor circuit boards having enlarged conductive traces and peripheral ground contact surfaces which enable large surge currents to pass to ground when the boards are mounted to a common grounding backplane.

Abstract: A surge protector is tested by injecting a current spike with an exponentially decaying waveshape (12) through the surge protector. The current is generated by connecting a voltage source (16) to the surge protector and controlling the current through the surge protector by a Darlington array amplifier (20) connected between the surge protector and ground. The Darlington array amplifier (20) is in turn controlled by first generating a reference pulse having a voltage waveform corresponding to the desired current waveform and comparing this reference voltage with a voltage feedback from the Darlington array amplifier (20) to in turn generate an error voltage which is coupled into the amplifier (20). Additionally, differential amplifier circuits (44 and 46) monitor the voltage impressed on the amplifier (20) and reduce the input voltage to the amplifier (20) significantly if the voltage impressed on the amplifier (20) is greater than a predetermined fraction of the voltage source (16).

Abstract: The present invention is a surge protector circuit and method of protecting electronic equipment which do not load down a circuit at high frequencies and do not degrade a signal in high speed data transmission. A gas tube is connected in parallel with low capacitance diodes and an avalanche semiconductor device, such as a TVS. The diodes and the avalanche semiconductor clamp the voltage transient and allow the slower gas tube more time to fire, discharging the surge. The addition of the low capacitance diodes in series with the avalanche semiconductor, reduces the line-to-line and line-to-ground capacitances of the surge protector and keeps the surge protector circuit from loading down the rest of the circuit and degrading the signal.