Abstract: An apparatus for protecting an integrated circuit is applied to an electrical apparatus having a control unit. The control unit is used for controlling the integrated circuit and the protecting apparatus. The protecting apparatus includes a power input terminal, a power output terminal, and a control terminal. The power input terminal is used for receiving a power, and the power output terminal is used for outputting the power to the integrated circuit. The control terminal is used for receiving a control voltage of the control unit. When the control unit is at the power on mode, the control unit outputs the control voltage of a first level to prevent the power being input to the integrated circuit. Over a predetermined period of time, the control unit outputs the control voltage of a second level, so that the power can be input to the integrated through the protecting apparatus.

Abstract: A power limiting circuit for power supply that is controlled by a power supply control module includes a shunt regulator having a reference input operatively connected to a voltage input that receives a voltage representative of the power supply control module connected thereto. The shunt regulator is biased on when the voltage at the reference input increases above a reference voltage established at the voltage input. A transistor is operatively connected to the shunt regulator and to an output operatively connected to the power supply control module and has a voltage that is representative of voltage operating the power supply control module. The transistor is biased on from the shunt regulator such that the shunt regulator and transistor form a latch when the voltage at the output reduces below an off voltage level to turn off the power supply, dropping the input voltage, and restarting the power supply in a restart cycle.

Abstract: A GFCI is provided that has secondary test switch contacts. In case closing of the primary test switch contacts fails to trip the GFCI, subsequent closing of the secondary test switch contacts results in a short circuit between the AC input terminals of the GFCI. The short circuit blows a fuse disposed on the line side of the GFCI. The blowing of the fuse disables the GFCI and/or provides an indication to the user that the GFCI is defective.

Abstract: A voltage transient suppression circuit for power electronic circuits comprising: a snubber circuit having a resistor and a first and second capacitive element connected in series with a switching power semiconductor; and a sensing logic device connected in parallel with the snubber circuit; the logic circuit being configured to receive voltage signals indicative of said first and second capacitive elements.