Abstract: A telephone based control system comprises a central control console, a digital time division multiplexed (TDM) telephone system incuding a PBX matrix switch with signal ports adapted for direct connection to PBX primary port telset devices and to the central control console, and including primary port telsets adapted for connection to PBX secondary port devices, the control system further comprising secondary port control units, each connected to an associated one of the primary port telsets, for controlling the operation of one or more controlled devices located in proximity to the associated telsets.

Abstract: The contaminants in the exhaust gas emissions from a motor vehicle such as carbon monoxide (CO) and hydrocarbons (HC) are analyzed within a nondispersive infrared analyzer which includes means for assuring that the vehicle being tested has achieved a predetermined engine speed and that no blockage has occurred in the gas transport system when the measurements are made.

Abstract: The rpm, dwell and timing of an internal combustion engine are measured by starting and stopping a digital counter on the leading edge of pulse waveforms generated either within the engine or by a timing light. For rpm measurement, the counter is started when the ignition points open, and stopped upon the next opening of the points. To measure dwell the counter is started by the opening of the points and stopped when the points close, and this count is subtracted from the rpm count to obtain dwell. Timing is measured by starting the counter upon the firing of the number one cylinder, and providing an additional signal delayed in time as a function of the distributor advance to stop the counter. The count in the counter is converted to rpm, dwell or timing by either analog or digital techniques. A high energy ignition adapter circuit prevents triggering of the counter by a false indication of the opening of the points in vehicles using high energy ignition systems.

Abstract: The rpm, dwell and timing of an internal combustion engine are measured by starting and stopping a digital counter on the leading edge of pulse waveforms generated either within the engine or by a timing light. To measure rpm and dwell only the low coil signal is used. For rpm measurement, the counter is started when the ignition points open, and stopped upon the next opening of the points. To measure dwell the counter is started by the opening of the points and stopped when the points close, the resultant count being the inverse of dwell, and this count is subtracted from the rpm count to obtain dwell. Timing is measured by starting the counter upon the firing of the number one cylinder, and providing an additional signal delayed in time as a function of the distributor advance to stop the counter. The count in the counter is converted to rpm, dwell or timing by either analog or digital techniques.

Abstract: The condition of the ignition coil and capacitor of an internal combustion engine are analyzed by determining the number of zero cross-overs in the ringing of the low coil voltage as well as whether or not the low coil voltage exceeds a threshold magnitude, during the spark period of a disconnected spark plug while the engine is running. In one disclosed embodiment, the cross-overs in the low coil ringing voltage and the times that the threshold is exceeded are counted over a moderate number (such as 16) of revolutions of the distributor and then the average number of ringing cross-overs is combined with the approximate percent of time that the threshold voltage is exceeded during that number of revolutions to present signals indicating that the ignition is normal, the coil has shorted turns or intermittent arc-overs, or that the capacitor is open.