Abstract: A folding sawhorse including a rigid planar center panel and a pair of hinged rigid planar end panels which can be folded flat against the rigid planar center panel when the sawhorse is not in use and swung into position and locked in place when the sawhorse is in use.

Abstract: A wiring concentrator (160) for Fiber Distributed Data Interface (FDDI) networks employs only two PHY modules (182 and 184) for initialization of all attached stations (174, 176, 178, and 180). A bank of switches (204, 206, 208, and 210) initially switches one of the stations into full-duplex communication with one of the PHY modules (182), with which it performs the initialization process. The attached station (174, 176, 178, or 180) is then switched into a loop formed with the other PHY (184), in which loop the station remains in the active state that it reached as a result of the initialization process. The process is then repeated for each attached station. A separate PHY module thus is not required for every attached station.

Abstract: A wiring concentrator (160)for Fiber Distributed Data Interface (FDDI) networks employs only two PHY modules (182 and 184) for initialization of all attached stations (174, 176, 178, and 180). A bank of switches (204, 206, 208, and 210) initially switches one of the stations into full-duplex communication with one of the PHY modules (182), with which it performs the initialization process. The attached station (174, 176, 178, or 180) is then switched into a loop formed with the other PHY (184), in which loop the station remains in the active state that it reached as a result of the initialization process. The process is then repeated for each attached station. A separate PHY module thus is not required for every attached station.

Abstract: A circuit useful to protect motors and other dynamoelectric machines from overtemperature conditions caused by a fault condition such as locked rotor, overcurrent, or the like. The circuit comprises first and second tuned branch circuits coupled to the power lines of the motor or other machine along with an oscillator circuit and detector circuit and a switch to change the effective impedance of one of the tuned circuits. The tuned circuits each includes a series connected inductance and capacitance while the switch, which can be an electro-mechanical device such as a heat responsive thermostatic switch, or a solid state switch such as an NTC or PTC thermistor is connected around one of the components of one of the tuned circuits. The oscillator may be a conventional one adapted to provide a selected frequency, preferably high relative to that of the motor power supply.

Abstract: A circuit is shown useful to protect dynamoelectric machines from overtemperature conditions. The circuit comprises first and second tuned circuits coupled to the power lines of the dynamoelectric machine along with an oscillator for injecting a selected frequency signal in the line and a detector for detecting the signal when the tuned circuits are resonant. A thermally responsive switch comprising an electromechanical bimetal switch or a solid state PTC or NTC switch is adapted to be disposed in heat conductive relation with the dynamoelectric machine and is electrically coupled to one of the tuned circuits so that the temperatures below a selected level the switch will be in one state, e.g. a low impedance state, precluding resonance while at temperatures above the selected level the switch will be in an opposite state, e.g. a high impedance state, permitting resonance.