A small alarm timepiece having a timepiece movement, an electrically operating buzzer as an acoustic alarm signal delivery means, a battery detachably mounted on the timepiece movement for energizing said buzzer for its operation, and an alarm switch for on-off control of the operation of the buzzer. This alarm switch is operatively connected with the movement so as to be closed at a preset time point and to remain closed for a certain predetermined operation period. The drive circuit for the buzzer is designed as a free-running oscillator having an oscillator transistor. In addition to the alarm switch, there is provided a switching transistor operatively connected with the first mentioned transistor. There is provided a CR-time limiting circuit operatively connected with the switching transistor for control thereof. In this way, the operating period of the buzzer is limited to only a small fraction of the closure period of the alarm switch which is adapted for being mechanically closed at the preset time by the action of an alarm control mechanism fitted to the timepiece movement. In this way, the power consumption of the electronic alarm can be minimized.
An electricity supply structure for a piezoelectric vibrator includes a circuit board and a coil spring having one end positioned in contact with the circuit board and the other end with a portion extending toward the center of the spring and a rising contact portion which stands on the extending portion at a central portion of the coil spring. A piezoelectric vibrator is in contact with the free end of the rising contact portion of the coil spring and a positioning rod for positioning the coil spring is formed integrally with the base plate and is provided at the distal portion thereof with a groove in which the extending portion is insertable to prevent radial movement of the rising contact portion relative to the piezoelectric vibrator.
An electronic timepiece including a piezoelectric type alarm buzzer wherein the caseback functions as the buzzer diaphragm is provided. The piezoelectric element is mounted on the caseback and a battery for driving the timepiece is mounted on the piezoelectric element with an electrical insulating member therebetween for preventing short-circuiting between the battery and piezoelectric element. In an exemplary embodiment, the electrical insulating member for mounting for holding the battery is mounted to the piezoelectric element at a peripheral portion in order not to effect adversely the sound level. Alternatively, when design considerations require the battery may be mounted in a more central portion of the piezoelectric element, an angular insulating member having a central opening is used so that the insulating member contacts the piezoelectric element at the periphery thereof.
An electronically powered watch is disclosed which has an audible signal producing alarm system incorporated into the watch structure. The audible signal is produced by a vibrating membrane located laterally adjacent to the watch battery within the watch case. The audible signal emanates from the case by radial sound discharging openings provided through the watch case. The structure minimizes the overall height of the watch structure. Access to the battery is provided by a removable battery cover over an opening in the rear cover of the watch. The battery may be removed and a new battery installed by merely removing the battery cover without disturbing the vibrating membrane or removing the entire rear cover of the watch.
An electronic timepiece of analog type display provided with alarm means and a switch for setting or cancelling said alarm means, and with an indication being given as to whether the timepiece is in the alarm set or alarm cancelled status, by modulating the advancement of the seconds hand
