| 摘要 |
<p>An A.C. motor is connected into a transistor bridge which includes a small current sensing resistor. The bridge is operated to supply alternating half cycles of current to the motor and resistor. The voltage drop across the resistor is compared in a comparator with a reference voltage which is equal to a fixed voltage minus a percentage of the bridge D.C. supply voltage. When the voltage drop across the resistor exceeds the reference voltage a gate means is closed to render the bridge transistors non-conductive.</p> |
