Pulse-width modulation control system for multiple solenoids utilizing a single A/D converter in which the A/D conversion time is used to control the sequential operation of the solenoids

摘要

A pulse-width modulation control system having a power source, driver circuits connected to the power source, and two solenoids, such as those for a vehicle automatic transmission, connected to the power source through the driver circuits, and pulse trains of a predetermined PWM duty ratio are supplied. The supplied currents are detected and A-D converted. In the system, one pulse train lags behind the other at the leading edge. When PWM controls two solenoids at the same time using an on-board microcomputer, two voltage memory circuits are additionally needed, since the microcomputer ordinarily has only one A-D converter. With the arrangement, only one voltage memory circuit is needed, rendering the system configuration simple.