From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Different flasher and control switch systems for vehicle indicators.
| Identifier | ExFiles\Box 113\3\ scan0143 | |
| Date | 15th January 1940 guessed | |
| - 4 - depends the type of flasher to be used. Fig. 1. illustrates the flasher and circuit being used on the 1940 Buick signal. This flasher is of the combination magnetic and hot wire type, flashing both front and rear signals simultaneously. Separate contacts controlled by the magnet are used for operating the double pilot bulbs, which indicate by the absence of flash-ing when either front or rear signal bulb burns out. The doubt pilot lights placed behind arrows on the instrument cluster, serve to indicate to the driver, the direction in which the signals are operating. This unit has proven very dependable and the arrangement has served the purpose well. Fig. 2. illustrates an alternative means for operating two pilot bulbs where it is not desired to use the magnetic type shown in Fig. 1. This type of flasher, although somewhat less expensive than the combination magnetic type described above, requires the use of two units, since no relay circuit is provided for operating the pilot bulbs. As in the circuit shown in Fig. 1, the pilot bulb does not flash when either front or rear signal bulb is burned out. It differs in operation, however, from Fig. #1 in that, if the rear signal bulb burns out the front signal bulb continues to light, but does not flash. It, therefore, perhaps is not quite as desirable as the arrangement shown in Fig. 1, whereas the remaining signal continues to flash. With this system it will be noted that both sides of the pilot light must be insulated. This requires a somewhat more complicated pilot bulb arrangement than the magnetic type where standard snap type sockets can be used, since one side of the socket is grounded. Fig. 3. illustrates a circuit for a simplified system, using only one pilot bulb in combination with a snap spring hot wire flasher. However, the operation is exactly the same as provided in the circuit shown in Fig. 2, except the pilot bulb does not serve to indicate in which direction the signals are flashing. With this arrangement the pilot bulb should be located to illuminate a suitable mechanical indicator connected with the operating switch lever. There is no intention to make a specific recommendation with regard to the use of these flasher units, but it should be stressed that uniform operation of pilot lights and suitable means of indicating which signals are in use, should be provided. It has been found that flashers calibrated to operate within a range of 90 to 100 flashes per minute at 6.5 volts give a satisfactory indication. A higher rate of flash is not desirable, inasmuch as under operating conditions on a car, the voltage may somewhat exceed 6.5 which will, of course, increase the rate of flash, and thus shorten the interval of time for the bulb filament to reduce in brilliance. "Manual, Automatic, and Semi-automatic Operation of Control Switches": One of the most controversial phases of this subject has been the manner in which direction switches should be turned on and off. For this reason, and the element of cost, standardization will be more difficult to accomplish. The systems may be divided into the following groups -- (1) Straight manual operation in which a conveniently located lever is turned on manually when approaching the turn, and turned off manually after the turn has been completed. | ||