| 摘要 |
The specification describes an improved motor control system for adjustable speed control of DC motors where the armature voltage is adjusted by phase controlled thyristors. Previous systems have used a closed loop feedback system combined with IR compensation which require different compensation factors for high and low speeds in smaller inexpensive motors. The present invention provides a programmable compensation response more economically than in the prior art control circuit, and also achieves thermal compensation for holding set speeds during changing control temperatures. This system is more immuned to malfunctions caused by momentary interruptions of supply voltages and reduces losses and heating incident to the powering of the control circuitry. The major segements of the motor control circuitry include: power semiconductor bridges, a pulse generator, an error comparator/amplifier, and a speed reference circuit. |
