| 摘要 |
A bidirectional chopper transconductance amplifier for driving a motor winding provides a duty cycle signal as an input to an H bridge circuit that provides a voltage output across the motor winding. The amplifier also provides a direction input that determines the polarity of the voltage output across the motor winding. An RS flip-flop is set by the pulses of a cyclical chopper sync input signal and is reset as a function of the current in the motor winding and a command current input to produce the duty cycle signal. A first pair of flip-flops, one clocked by the trailing edges of the chopper sync input signal pulses and the other clocked by the trailing edges of the chopper sync input signal pulses delayed by a specified time, detects whether the RS flip-flop is reset prior to pulse trailing edge of the current cycle and prior to the specified time of the prior cycle. A second pair of flip-flops, clocked by the trailing edges of the delayed chopper sync input signal pulses, together with an XOR gate detect whether the direction input was reversed between the prior and current cycles. Logic circuitry combines the outputs of the first pair of flip-flops with the output of the XOR gate and the status of the RS flip-flop to generate a toggle function to reverse the direction input.
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