摘要 |
<p>A control circuit for controlling the effective power to a load from a power source of substantially constant direct current voltage includes a first or main solid state switching device for placing the load and the power source in series. Suitable circuitry including a commutating capacitor chargeable in a direction such that its discharge will terminate conduction of the main switching device further includes resistive means serving to maintain the capacitor in constant communication with the power source. Also provided is a means for providing dynamic braking of a direct current motor load through a resistive element such that the armature terminal voltage is adjusted linearly with the speed thereof.</p> |