| 摘要 |
PURPOSE:To detect disconnection of a rotary type differential transformer and disconnection in the signal system thereof accurately by providing a switch which operates by a position signal 0+ or -alphaV of the differential transformer. CONSTITUTION:Three contacts 5t, 6t and 7t which a position signal 3 turns ON with output 5 of a zero setting device 4 in the range of 0+ or -alphaV, below the position of 50-beta% of a reset switch of a device to be driven and above the position of 50+beta% respectively are connected both in series and parallel between control lines P and N with an alarm relay 8. In other words, the alarm relay 8 is operated on the condition that the contact 5t and both or either of the contacts 6t and 7t turn ON and the contact 8t is turned ON to output an alarm output 9. If alpha is set at a small value (for example, alpha<beta/10), any disconnection can be detected quickly and accurately even when occurring near the position of 50%. |
