Control for an electromagnetic brake for a multiple-ratio power transmission that has a brake actuation counter

摘要

A control system and method for an electromagnetic clutch brake, including an electromagnetic clutch brake actuator coil surrounding a power input shaft for a multiple-ratio transmission in a vehicle powertrain. A protective circuit of the control system normally monitors data inputs from a databus that may indicate conditions that are not favorable for clutch brake actuation. The protective circuit prevents actuation of the clutch brake under such conditions. In the event the data inputs are not available from the databus, the protective circuit permits operation in a fall-back mode in which a brake ON timer is checked prior to clutch brake actuation. A primary counter is incremented with each normal clutch brake actuation and a secondary counter is incremented with each fall-back clutch brake actuation.