Patent GB-190811068-A (GB)
Title: Improvements in Electro-mechanical Regulators or Governors for Electric Generators, Electric Furnaces and the like.
Filed: 1908-05-21
Granted: 1909-01-07
Abstract: 11,068. Soc. Franþaise des ProcÚdÚs J. L. Routin pour le Compoundage Electro-mÚchanique des Groups ElectrogÚnes. May 24, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Regulating ; switches.-The voltage of a generator is regulated by means of an electro-magnetic switch, which closes the circuit of one or the other of two electro-magnetic relays controlling the continuous or intermittent rotation of a motor operating a rheostat in the field circuit of the generator or the valve of the prime mover. The electro-magnet switch consists of three coils 3, 4, 5 arranged in series with a resistance 6 in the circuit to be controlled, and operating an arm 1 in opposition to a spring 7. The arm 1 carries a permanent or an electro-magnet 8, the poles 9, 9<1> of which are adapted to contact with springs 10, 10', and the armature 25 of an electro-magnet 24. When the voltage of the circuit containing the coils 3, 4, 5 falls below a certain minimum, the pole 9 contacts with the spring 10, thereby closing the circuit of 'the electro-magnetic relay 11 connected between the points 12, 13 of a resistance used as a potentiometer. The armature 16 closes the circuit of the motor armature 19 connected to the rheostat by engaging with the spring-mounted contact 18 ; it then engages with the contact 22, thereby ener- 'gizing the coil of the electro-magnet 24. If the voltage variation in the circuit to be controlled exceeds a predetermined amount, the armature 19 will rotate continuously, but if the variation is below this valur, the force of the magnet 24 upon its armature 25 opposing the force of the spring 7 separates the contacts 9, 10, thereby de-energizing the relay 11 and short-circuiting the motor arma: ture 19. By repeating these operations the rheostat is operated intermittently. The value of the voltage a.t which the intermittent operation shall cease and the continuous operation begin is varied by varying the distance between the magnet 24 and its armature 25. To prevent sparking at the contacts 18, 22, it is arranged that when the armature 16 is about to contact with the magnet 11 the energization of the latter is considerably weakened. This is obtained by making the resistance of the coil of the magnet 24 very small compared with the resistance between the points 12 and 23 of the potentiometer. When the arm 16 bridges the contacts 22, 18, the part 12 to 23 of the potentiometer is short-circuited, and consequently the potentials between these points and between 12 and 13 are reduced, thereby reducing the current in the magnet 11 placed between these points. In addition to this, a quick make-and-break is obtained by means of the means of the magnetic attraction between the magnet 8 and the resilient spring 10. When the voltage increases, the relay 11' is energized and the motor armature 19 caused to rotate in the opposite direction. If an alternator is to be regulated, the coils 3, 4, 5 are placed in the circuit of an auxiliary direct-current generator driven by a small synchronous motor. When the continuous-current generator is to be regulated, the motor armature 19 preferably operates the admission valve of the engine. To prevent oxidation, the poles 9, 9<1> and springs 10, 10<1> are coated with a thin layer of nickel or other non-oxidizable metal.