Abstract: An electronic circuit arrangement for switching an electrical load disposed intermediate a power source and a ground includes a combinatorial logic block for receiving and processing at least one condition signal and for generating a first enabling signal. A biasing element generates a bias voltage upon receiving the first enabling signal. A first switch disposed intermediate the electrical load and the power source conducts upon application of the bias voltage enabling passage of an electrical supply current from the power source to the electrical load. A fail-safe circuit operation is achieved with the use of a microprocessor which generates a second enabling signal feeding into the biasing element and a second switch disposed intermediate the electrical load and the ground and which conducts upon application of a third enabling signal from the microprocessor thus enabling passage of the electrical supply current to ground.

Abstract: An electronic circuit arrangement for switching an electrical load disposed intermediate a power source and a ground includes a combinatorial logic block for receiving and processing at least one condition signal and for generating a first enabling signal. A biasing element generates a bias voltage upon receiving the first enabling signal. A first switch disposed intermediate the electrical load and the power source conducts upon application of the bias voltage enabling passage of an electrical supply current from the power source to the electrical load. A fail-safe circuit operation is achieved with the use of a microprocessor which generates a second enabling signal feeding into the biasing element and a second switch disposed intermediate the electrical load and the ground and which conducts upon application of a third enabling signal from the microprocessor thus enabling passage of the electrical supply current to ground.

Abstract: A service control processor includes a plurality of service feature processors each corresponding to selected telephone service, and a plurality of call processing records, each corresponding to a customer of a service provider. The customer call processing records specify services subscribed to by the caller. A feature manager processor manages call processing and the implementation and execution of services by managing the individual service feature processors. In an alternative embodiment, multiple feature manager processors are included, and a trigger manager selects between them in response to call processing triggers.