Abstract: A bobbin for use in a three-phase line reactor. The bobbin includes a tubular main body with a first end, a second end, a first side, a second side, and a core that extends from the first end to the second end. The main body also has two radially-extending flanges; one on its first end and another on its second end. Four tabs extend axially from the main body and are integral with it. A first tab is positioned on the first end of the main body extending from the first side and a second tab is positioned opposite the first tab on the second side. A third tab is positioned on the second end of the main body extending from the first side and a fourth tab is positioned opposite the third tab on the second side. The integral tabs eliminate the need for metal support bars used to hold and align laminations inserted into the cores of the bobbins. Thus, fixing laminations in place is more accurate and repeatable than with prior bobbins.

Abstract: A three-phase, low-pass filter for use in an electronic speed control system and wherein an adjustable speed drive is disposed in signal transmitting relation relative to an electric motor by an electrical conduit having a predetermined length, and wherein each single-phase circuit of the three-phase, low-pass filter includes an inductor having input and output nodes, a first resistor electrically coupled in parallel to the inductor, a second resistor having input and output nodes, and wherein the input node of the second resistor is electrically coupled to the output node of the inductor, and a capacitor having input and output nodes, and wherein the input node of the capacitor is electrically coupled to the output node of the second resistor, and wherein the low-pass filter is electrically coupled to the electrical conduit and operable to substantially filter out frequencies that tend to excite the natural resonant frequency of the electrical conduit.

Abstract: A monitoring apparatus for a tuned harmonic filter is provided to prevent electrical system and filter damage. A tuned harmonic filter is provided in an electrical system to prevent overheating, motor damage, flickering lights, capacitor failure, etc. The present invention provides a sensing device in conjunction with the filter reactor to provide a signal indicative of the true operating condition of the filter. A monitoring circuit compares the signal with normal operating conditions of the filter to determine if a "fault" is occurring. Timing devices provide for a delay or rapid disconnection of the filter and/or electrical system. Indicator devices are provided to aid in diagnostic analysis of an electrical system. A remote indicator device may be included.