| 摘要 |
PURPOSE:To permit contactless start by serially connecting the secondary side of a control transformer connected in parallel with a power source to a search coil wound in phase with a main winding wherein the search coil is connected to the gate of a triac connected in series with a starting winding. CONSTITUTION:A triac 3 is connected in series with a starting winding 2. A search coil 5 is provided in the grooves of a stator in phase with a main winding 1 and also the search coil 5 and the secondary winding of a control transformer 4 connected in parallel with a power source are connected in series with reverse polarity each other and connected to the grid of the triac 3 through a resistor 6. With the power source fed to the main winding 1, the triac 3 will be closed by the secondary electromotive force et of the small-sized control transformer 4. With a motor started, the speed electromotive force es of the search coil 5 generates to cancel et and the triac 3 will be opened. |
