Abstract: A speedometer system for automatically calibrating a speedometer by adjusting the speedometer drive to take into account the varying wheel sizes of a locomotive which comprises: at least one speed probe; a speedometer drive; a speedometer; a gate for enabling and disabling the normal speed signal from the speed probe; a programmable counter for transmitting a test speed signal to the speedometer drive to produce a test speed current; a gate for enabling and disabling the transmission of the test speed signal to the speedometer drive; and a microprocessor which is capable of processing a signal representative of wheel size, calculating a test signal frequency, causing the counter to create and transmit the test signal, measuring the speedometer current, and signaling a digital potentiometer to increase or decrease the resistance on the speedometer drive until a full scale current value is measured.

Abstract: An inverter power supply system (DC input, AC output) with a bridge type power stage having switching devices (transistors) in each arm is used to create an AC output voltage across the bridge center terminals. The transistors execute numerous switching cycles per period to create an output waveform that has a low frequency AC component together with a high frequency AC component that is removed via a low pass filter. Unless some means is provided to prevent it, a DC component is usually present at the output of the inverter as well. This DC component will cause saturation in transformer coupled loads with attendant excessive inverter device currents unless means are provided to limit or eliminate the DC component of the output voltage.

Abstract: A calorimetry system for measurement of the heating value of coal, having a combustor 24 and a mixing unit 30 wherein heat from combustion gases is transferred to air. The system has a gravimetric feeder 64 for providing coal at a measured mass feed rate; the coal including any moisture present therein. The coal is pulverized in an air-driven mill or pulverizer 14 which is fed coal from the feeder and is separated by a cyclone separator 16 into two streams; one carrying coal and air mixed together in a controlled ratio to the combustor. The air which drives the separator, together with fines of the coal and moisture is fed to an afterburner 26 of the combustor so that the thermal dynamics of the entire coal stream is involved in the heating value measurement.

Abstract: A calorimetry system for measurement of the heating value of coal having a combustor 24 and a mixing unit 30 wherein heat from combustion gases is transferred to air. The system has a gravimetric feeder 64 for providing coal at a measured mass feed rate; the coal including any moisture present therein. The coal is pulverized in an air-driven mill or pulverizer 14 which is fed coal from the feeder and is separated by a cyclone separator 16 into two streams; one carrying coal and air mixed together in a controlled ratio to the combustor. The air which drives the separator, together with fines of the coal and moisture is fed to an afterburner 26 of the combustor so that the thermal dynamics of the entire coal stream is involved in the heating value measurement. Instrumentatoin measures the flow rates of cooling air, primary air which carries the coal streams into the combustor and secondary combustion air as well as the mass flow rates of the coal into the combustor as measured with the gravimetric feeder.