摘要 |
In a preferred embodiment, a high-frequency, pulse-width-modulated, power-transistor, DC motor speed controller having current limiting in both drive and regenerative modes, essentially constant ramping rates regardless of whether or not the operator switches to neutral before changing direction, a simple sequencer which controls the timing of four functions-both drive and regenerative current measuring circuits and both drive and regenerative transistors, a highly effective transistor filter capacitor arrangement, and circuitry in which the level of regenerative current is used as an input to control the current under which the direction relays switch. |