Abstract: A device (10) is disclosed for intercepting the input of a system (23) of an internal combustion engine (12) normally provided to a solenoid valve (22) for actuating a fan clutch (20). A pressure switch (24) is provided in the pressure line between the solenoid valve (22) and the fan clutch (20). The input is received by terminals (27, 28) and is passed on to a transistor (53) which turns on and allows current flow to the solenoid valve (22) during a first period of time. If a second transistor (48) turns on because the pressure switch (24) remains open as a set point is not sensed in the pressure line and does not discharge a time delay circuit formed by a combination of a resistor (44) and a capacitor (46), then the voltage of the gate of the first transistor (53) is pulled down to turn the transistor (53) off and interrupt the current flow to the solenoid valve (22).

Abstract: A device (10) is disclosed for intercepting the input of a system (23) of an internal combustion engine (12) normally provided to a solenoid valve (22) for actuating a fan clutch (20) when rotation of a fan (16) is desired. The input is received by terminals (42, 43) and is conditioned and passed on to a timer (96) and a controller (97). A vacuum switch (24) senses whether the fan (16) is rotating and provides a second input to the controller (97). In the event that an input is provided by the system (23) and the time delay signal has been provided by the timer (96) and also in the event that an input is provided by the system (23), the time delay has expired, and the second input is provided by the vacuum switch (24), the controller (97) provides an actuation output to terminals (71, 73) connected to the solenoid valve (22) by use of actuation provisions (98) to actuate the fan clutch (20).

Abstract: The present invention is an interconnection of a loop analysis test system (LATS) to a digital switching system. This arrangement includes the utilization of existing network units to establish a path connection from the computer of a LATS system to a measuring unit of the LATS system. This path through the digital switching system provides for the appropriate signaling requirements in order to simulate a telephone call to the digital switching system for connection to a subscriber. Another path is provided to connect the measuring unit to the subscriber line to be tested via a special access network. In addition, this arrangement includes a data base in the CPU switching system to provide for determining whether the connection of this path through the switching system is for a test access or for normal calling functions. The data base also records the interconnection of equipment such that the proper subscriber's line may be accessed when called by the LATS system.

Abstract: The present invention is an interconnection of a loop analysis test system (LATS) to a digital switching system. This arrangement includes the utilization of existing network units to establish a path connection from the computer of a LATS system to a measuring unit of the LATS system. This path through the digital switching system provides for the appropriate signaling requirements in order to simulate a telephone call to the digital switching system for connection to a subscriber. In addition, this arrangement includes a data base in the CPU switching system to provide for determining whether the connection of this path through the switching system is for a test access or for normal calling functions. The data base also records the interconnection of equipment such that the proper subscriber's line may be accessed when called by the LATS system.

Abstract: An arrangement for testing a plurality of subscriber lines, which are operationally connected to an electromechanical switching system is shown. Operational service is to be transferred from the electromechanical switching system to a digital switching system. This arrangement provides for automatically verifying the connection of the subscriber lines to the digital switching system and determining whether the proper ring signalling is transmitted to each subscriber.

Abstract: An arrangement for testing a single subscriber line, which is operationally connected to an electromechanical switching system is shown. Operational service is to be transferred from the electromechanical switching system to a digital switching system. The arrangement provides for isolating subscribers which share common line equipment, for verifying the subscriber's line and its ringing characteristics.

Abstract: An arrangement for automatically testing a plurality of subscriber lines, which are operationally connected to an electromechanical switching system is shown. Operational service is to be transferred from the electromechanical switching system to a digital switching system. This arrangement provides for automatically verifying whether the digital switching system is applying the proper ringing signal to each subscriber by a comparison with that applied by the electromechanical switching system.