EP 0327989 B1 19910828 - STEPPER MOTOR CONTROL CIRCUIT, ESPECIALLY FOR WATCHES
Title (en)
STEPPER MOTOR CONTROL CIRCUIT, ESPECIALLY FOR WATCHES
Publication
Application
Priority
CH 51388 A 19880212
Abstract (en)
[origin: EP0327989A1] The control circuit (19) receives a supply voltage (Vb) provided by a battery (7), and in response to a time-base signal (S3) it sends driving voltage pulses (Vm) to a stepping motor (5), the rotor of which causes the time (6) to be displayed. The driving pulses are also applied to the control circuit (19) which comprises an adjusting circuit (20), the function of which is to compare the voltage (Vm) of these pulses with a reference voltage (Vr) and to produce, in each pulse, interruptions, the duration and number of which are determined so as to keep the mean voltage of each pulse constant in the presence of a variation of the supply voltage. Under these conditions, the motor (5) is controlled by driving pulses of constant energy, whatever the voltage (Vb) of the battery (7). <IMAGE>
IPC 1-7
IPC 8 full level
G04C 3/14 (2006.01); H02P 8/02 (2006.01); H02P 8/12 (2006.01)
CPC (source: EP)
G04C 3/143 (2013.01)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0327989 A1 19890816; EP 0327989 B1 19910828; CH 672043 B5 19900430; CH 672043G A3 19891031; DE 68900226 D1 19911002; HK 142594 A 19941223; JP 2905856 B2 19990614; JP H01243891 A 19890928
DOCDB simple family (application)
EP 89101879 A 19890203; CH 51388 A 19880212; DE 68900226 T 19890203; HK 142594 A 19941215; JP 3125089 A 19890213