GB888253A - Improvements in or relating to electronic clocks or watches - Google Patents

Abstract

888,253. Clocks and watches. JAHRESUHREN-FABRIK G.m.b.H. A. SCHATZ & SOHNE. March 7, 1958 [March 9, 1957], No. 7426/58. Class 139. An electronic timepiece comprises a transisterised oscillatory circuit. In the first example, Fig. 1a, the circuit comprises a transistor 8 and coupling coils 13, 13a, 13b, capacitors 11 and 12 and temperature stabilizing resistors 9 and 10. The hands are driven by an electromagnetically operated pawl-andratchet mechanism. In a modified circuit, Fig. 1b, the coupling coil 13 is short circuited and the resistor 10 is replaced by a coil which cooperates with an oscillating permanent magnet or by a capacitor one plate of which is carried by an oscillatory member. The oscillatory circuit may be triggered by photoelectric means or by magnets carried by a balance to co-operate with a stationary coil or coils. In another example, Fig. 7, the circuit is in the form of a freely oscillating monostable multivibrator comprising transistors 45, 46, capacitors 47, 48 and resistors 49, 50, 51, 52. The frequency of oscillation may be changed by increasing or decreasing the value of the resistor 51. The multivibrator circuit may be modified as shown in Fig. 8. In another example, the coupling between two coils forming a differential transformer is altered by the expansion and contraction of the balance spring. Means may be provided whereby the battery can be recharged from the mains. For setting purposes the frequency of the oscillatory circuit may be increased by switching an additional capacitor into the transistor base circuit. If the timepiece has a striking mechanism such mechanism may comprise a drum 60, Fig. 9, having sets of studs 61-64 which co-operate with a spring contact 65 to energize a coil 66 the armature 67 of which serves as a hammer or clapper. A record tape or disc may also be used for this purpose.