A switching system for powering first and second electrical loads from a voltage supply, the electrical loads being operable from controls and adapted to be connected to the voltage supply by the switching system. The switching system includes switching circuitry having a control element which is responsive to a control voltage difference to cause the switching circuitry to become conductive, the switching circuitry having a switch terminal connected to a first supply line and another switch terminal connected to the first electrical load. The switching system also includes additional circuitry responsive to the controls for generating the control voltage difference when the voltage supply is connected to the first supply line thereby powering the first electrical load from the first supply line. The switching system further includes further circuitry responsive to the controls for generating first and second control signals. Also included in the switching system is a contactor responsive to the second control signal for connecting the voltage supply to a second supply line, the second electrical load connected to the second supply line and another contactor responsive to the first control signal for connecting the second supply line to the first supply line thereby connecting the voltage supply to the first supply line and for disconnecting the second supply line from the first supply line to interrupt power through the switching circuitry thereby discontinuing the supply of power to the first electrical load. Other forms of the switching system and a testing system are also disclosed.

A patch or access module usable with an insertable patch plug having a plurality of electrical contact elements. The patch or access module includes a circuit board, a first electrical circuit electrically connected with a first point on the circuit board, a second electrical circuit electrically connected with the second point on the circuit board and switch contact means for selectively making electrical connection between the first point and the second point and for making electrical connection between the first point and the electrical contact elements of the patch plug upon insertion of the patch plug into the patch or access module. The switch contact mechanism includes a first portion electrically engaged with the first point, a second portion adapted for selective electrical engagement with the second point and a third portion adapted for limited movement relative to the circuit board for electrical engagement with the electrical contact element of the patch plug when the plug is inserted into the patch module.

A testing implement that can be electrically connected to a test-alarm pa in a vehicle fire-suppression system for verifying the integrity of the panel circuitry. The testing implement can be used with the test-alarm panel installed in a vehicle or outside the vehicle (i.e., bench testing). The implement can also be used to test the integrity of electrical cables used in the fire-suppression system.

Apparatus and methods for testing multiconductor data cables. A test connector having plural elements is engaged with one connector of the data cable, and a test signal is applied to a preselected common element of the test connector. The test signal is conducted through one conductor of the data cable to a connector on a breakout box and terminals on the breakout box are interconnected with one another while the presence or absence of the test signal at elements of the test connector other than the common element is detected.

A power module with leads extending upwardly. The circuit components and connections of the power module are arranged upon a substrate having interface leads attached thereto extending away from the undersurface of the substrate. The interface leads extend through openings in a form fitting molded case. The case has an open center region to facilitate performance of final assembly steps upon the module and is subsequently covered with a rugged lid and is encapsulated with a suitable potting material. The interior of the module is filled with a gel to provide moisture-proof protection.