Electronic weighing scale

Abstract

A cordless electronic weighing scale which includes a load receiving element, such as a weighing pan, an electronic circuit including a battery, a load cell operatively attached to the load receiving element for weighing items and generating analog signals representative of items being weighed, an analog-to-digital converter connected with the load cell for receiving analog signals therefrom and converting them into digital signals, a first logic circuit connected between the load cell and the converter to cause analog signals to be transmitted to the converter in an on and off fashion, and a digital display circuit connected to the analog-to-digital converter to provide a digital display of analog signals from the analog-to-digital converter to indicate the weight of the items on the load receiving element. In the system a pulse plus a non-pulse constitutes a cycle and the pulse is about 1% of the cycle and the non-pulse is about 99% of the cycle. An ambient light switching circuit means is provided which is responsive to the presence of sufficient ambient light to be on and alternatively responsive to the lack of sufficient light to be off. The ambient light switching circuits are connected to the battery so energy is provided when the ambient light switching circuit is on but does not provide energy to the load cell and the amplifier, the main power-consuming components when the ambient light switching circuit are off.