| 摘要 |
1,184,708. Selective signalling. GARRETT CORP. 2 June, 1967 [6 June, 1966], No. 25704/67. Heading G4H. An A.C. signal whose frequency represents the angular speed of a rotary machine, e.g. a gas turbine, is converted to a train of trigger pulses which are applied directly to a set of AND gates and via a divide-by-two circuit to a set of monostable circuits the relaxation times of which correspond to preset, different fractions of the normal working speed, the monostable circuits providing the second inputs to the AND gates, whereby an output is obtained from a gate when the speed exceeds one of the present fractions. The gates may control the starting sequence, e.g. switch-off of starter motor, fuel supply, connection of load, and may also shut down the turbine if the maximum allowable speed is exceeded. |
