Method and apparatus for synchronizing the balance system of clocks or wrist watches

Claim 1

A circuit arrangement for carrying out a method of synchronizing a balance system of clocks and wrist-watches having an automatic drive circuit and a given vibration frequency comprising the steps of: generating a sync signal having a given frequency, one half of said given frequency being slightly different than said given vibration frequency of said balance system; controlling by said sync signal the conduction of said drive circuit once per semi-vibration of said balance system in such a manner that the more said given vibration frequency departs from one half of said given frequency the more the energy content of a primary pulse produced by said drive circuit is reduced; and producing automatically in said drive circuit a secondary pulse having the same polarity as said primary pulse as the energy content of said primary pulse is reduced, the energy content of said secondary pulse being dependent on the energy content of said primary pulse, both said primary pulse and said secondary pulse providing a constant total energy content for said drive circuit; said circuit arrangement comprising: a circuit to produce said sync signal; a driving transistor of given conductivity type; a control transistor of a conductivity type complementary to said given conductivity type; a balance system; a supply voltage source having a positive pole and a negative pole; a drive coil for said balance system having one end thereof coupled to one of said poles of said source; a first resistor coupled between the other end of said drive coil and the collector of said driving transistor; the emitter of said driving transistor being coupled to the other of said poles of said source; a capacitor having one plate thereof coupled to said one of said poles of said source; a second resistor coupled between the other plate of said capacitor and the junction of said drive coil and said first resistor; the emitter of said control transistor being coupled to said other plate of said capacitor; a third resistor and a fourth resistor coupled in series between said other of said poles of said source and the junction of said drive coil and said first and second resistors; the base of said control transistor being coupled to the junction of said third and fourth resistors; the collector of said control transistor being coupled to the base of said driving transistor; an auxiliary transistor of a conductivity type complementary to said given conductivity type, the collector of said auxiliary transistor being coupled to said other of said poles of said source, the emitter of said auxiliary traNsistor being coupled to said other plate of said capacitor and the base of said auxiliary transistor being coupled to the junction of said driving coil and said first and second resistors; and an additional transistor having its base coupled to said circuit to produce said sync signal and its collector-emitter path inserted at a given point in said circuit arrangement to control the conduction of said driving transistor.