Motorola Corporation

John H Aseltine

Robert W Deutsch

Edward E Li

Ralph M Mitchell

Stephen G Oller

Daniel D Prochaska, Sr

An improved battery charger apparatus and method with multiple range current control includes a programmable current source (101) for providing a charge current (105) to charge a battery (107). An amplitude of the charge current (105) is dependent on a charge demand signal (117) supplied to the programmable current source (101). A scaler (109) provides a scaled charge current signal (111), dependent on the charge current (105) and a current range signal (113). A charge current control unit (115) regulates the charge current (105) by providing the charge demand signal (117) to the programmable current source (101) dependent on the scaled charge current signal (111). More than one amplitude of the charge current (105) is provided to the battery (107), dependent on more than one current range signal (113) provided by the charge current control unit (115) to the scaler (109). Moreover, a constant amplitude of the scaled charge current signal (111) is maintained responsive to the more than one current range signal (113).

Battery charger apparatus and method with multiple range current control

Diagnostic fault test system and circuit sequentially tests a plurality of drivers (12) and their associated solenoid loads (13). Control signals (PM, SM) are provided to the drivers by a computer controller (11) to achieve desired solenoid actuation. The controller temporarily alters the control signals such that all of the drivers are forced into an on or off state for a first time period (t.sub.A or t.sub.B). After a delay (t.sub.Don or t.sub.Doff) a signal (V.sub.M) associated with each driver stage is monitored to determine if the driver and its load are operating properly. Then the controller resumes normal control of the drivers. The duration of the forced on/off state is short enough so as not to cause a change in the actuated/nonactuated state of the solenoid loads. Each monitored signal from the driver is sequentially compared to a high and low threshold (50, 51) to indicate either proper operation or the identification of one of two different types of fault which may occur. Drivers are preferably tested in both on and off states for proper operation and identification of a total of four different possible faults. Present system allows rapid testing of all drivers and their loads by use of a common transient setting delay time. Accuracy is improved since driver switching during fault monitoring is not permitted. Fewer components are needed since a single comparator (18) is used to sequentially compare each monitored signal for each driver with both high and low thresholds. Also, an indication of what type of fault is provided rather than just providing an indication that some fault exists.

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Buffalo Grove, IL, United States of America

John H Aseltine