Self-winding Gramophone Motor

Self-winding Gramophone Motor.

As gramophone users may know, clockwork and electric gramophone motors may have disadvantages when a pick-up is used in place of an acoustic soundbox. The convenience of electric reproduction is such that the inconvenience of winding up a clockwork motor is all the more obvious, and with some electric motors, it is difficult to prevent a slight induction effect between the motor windings and the pick-up.

Both these possible disadvantages are overcome in the new A.E.D. self-winding gramophone motor, which is a high-class clockwork motor automatically wound by an electric motor. This, obviously, overcomes the need for tedious winding, and at the same time there is no possibility of electrical interference, for the motor winds only when the clockwork motor is not working.

The motor is supported on a unit plate with an automatic stop. The electric drive is connected to the clockwork mechanism through the intermediary of a reduction gear, and the arrangement which prevents the electric motor over winding the spring is very simple.

The coupling consists of one member fixed to the winding shaft and one sliding member held in engagement by a coil spring, the tension of which can be adjusted.

When the gramophone motor spring is wound up to such a point that its tension exceeds that of the small coil spring holding the coupling members in engagement, the loose member of the coupling is forced back out of engagement and this not only disconnects the drive, but by means of a contact arrangement, switches off the driving motor.
The electric winding motor is of the universal type and can be used on alternating and direct current supplies of all the usual voltages. The current consumption is, of course, very low, for the motor is only is use intermittently for about 30 seconds at intervals of 3½ minutes.

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Tous les appareils de AED (A.E.D.) (Brand) Auto Electric Devices Ltd.; Brighton