Abstract: An information displaying device is provided with a display portion that displays an image based on display information and a predetermined driving voltage, a CPU that sets a boost target value of the driving voltage of the display portion, a voltage divider resistance circuit that divides a power supply voltage to generate output candidates of the driving voltage having plural output values, a selector that selects the output values, successively, based on tap selection signals from a lower rank of the output candidates of the driving voltages in the voltage divider resistance circuit to a higher rank thereof and boosts the driving voltage and a slow starter that compares an output value of the driving voltage boosted by the selector with the boost target value set by the CPU, determines whether or not the output value of the driving voltage reaches the boost target value, and drives the display portion at the driving voltage reaching the boost target value based on a determination result thereof.

Abstract: A power management system is disclosed in which ESL labels communicate with a server through a base station. The frequency and times at which each ESL label communicates with the server is optimized for the minimum communication necessary to provide up to date pricing and related information, and to simultaneously minimize consumed battery power for the ESL labels. The base stations and servers for the system are preferably operated from hard wired power.

Abstract: An information displaying device is provided with a display portion that displays an image based on display information and a predetermined driving voltage, a CPU that sets a boost target value of the driving voltage of the display portion, a voltage divider resistance circuit that divides a power supply voltage to generate output candidates of the driving voltage having plural output values, a selector that selects the output values, successively, based on tap selection signals from a lower rank of the output candidates of the driving voltages in the voltage divider resistance circuit to a higher rank thereof and boosts the driving voltage and a slow starter that compares an output value of the driving voltage boosted by the selector with the boost target value set by the CPU, determines whether or not the output value of the driving voltage reaches the boost target value, and drives the display portion at the driving voltage reaching the boost target value based on a determination result thereof.

Abstract: A power management system is disclosed in which ESL labels communicate with a server through a base station. The frequency and times at which each ESL label communicates with the server is optimized for the minimum communication necessary to provide up to date pricing and related information, and to simultaneously minimize consumed battery power for the ESL labels. The base stations and servers for the system are preferably operated from hard wired power.

Abstract: An electronic apparatus has a solar battery and a liquid crystal display unit for displaying a plurality of digits. A plurality of column electrodes are provided for each digit, and a plurality of common electrodes are provided for all the digits. A regulator receives and stabilizes the output voltage of the solar battery. A pulse generator generates a clock pulse signal. It is an oscillator with CMOS structure to permit implementation as a LSI. A CPU is driven by the stabilized voltage and the clock pulse signal to provide data to be displayed on the display unit. A liquid crystal driver circuit applies common signals, which can assume two different voltage levels and have a waveform with the logic level thereof inverted for every one held cycle period, to the common electrodes. The driver circuit applied column signals of either one of the two voltage levels corresponding to the display data to the column electrodes.

Abstract: A powder supply device with a solar cell is made up of a solar cell, a seconary battery, and a voltage control unit. The voltage control unit controls the output voltage of the solar cell, and produces first and second output voltages. The first output voltage is for charging the secondary battery. The second output voltage is for driving a circuit, such as the logic circuit of an electronic calculator.

Abstract: An envelope control device for the piezoelectric buzzer of the invention applies voltages changing with time to both surfaces of a sound generator for push-pull operation for generating an electric tone. The sound generator comprises an oscillating plate with a piezoelectric element attached thereto, and in response to a tone signal outputted from a tone signal generating circuit, it generates an electric tone. By the push-pull operations, an envelope is applied to the electric tone generated.

Abstract: In a key input indicating tone generating system for small-sized electronic devices, key switches are classified into a plurality of groups according to their function. When key switches belonging to a group of key switches are operated, music tones are generated. When the key switches of at least one of the remaining groups of key switches are operated, tones different from the above mentioned tones are produced.

Abstract: In a music tone generating system, of entry data keyed in by a plurality of entry keys related to the music tones, the entry data falling within the maximum digits which can be displayed by a display device are displayed by setting up one mode selected. When an entry key is operated to enter entry data exceeding the maximum digits while the former entry data remains displayed, the music tone corresponding to the key depressed may also be generated.