Abstract: A non-contact IC system 1 is mounted within the casing of a mobile telephone 100 and it includes: an antenna coil 11; an IC module 12 for receiving power and communication information via radio waves received by the antenna coil 11; a central arithmetic processing unit 13 for controlling the entire system and controlling drive power supply to the IC module 12; a regulator 14 for providing drive power to the IC module 12; a voltage detection circuit 15 for detecting the power supplied via the antenna coil 11; a battery 16; a bus 17; and a switch 18. The central arithmetic processing unit 13 controls the drive power supply to the IC module 12 in accordance with the result of detection of power supplied via the antenna coil 11 and the communication state of the IC module 12.

Abstract: An electronic record keeping device for recording numerical data under different items. The device has a casing and a memory having a plurality of sections. The number of the sections corresponds to the number of items. Each section has a first memory area for storing a budget data and a second memory area for storing a cumulative expenditures. A key board provided on the casing has number keys for effecting the input of a numerical data, a plurality of item keys for effecting an access to a corresponding section in the memory upon depression of one item key, a mode key for changing the mode between a first mode for entering the budget data in the first memory area, and the second mode for entering the cumulative expenditure in the second memory area.

Abstract: An electronic learning aid includes a circuit for automatically developing problems, a display for displaying the problems, an input for introducing a calculated answer, and a determination circuit for detecting whether the introduced answer is correct. The display includes a first display unit of plural digits for displaying the problems, and a second display unit of plural digits for displaying the problem number, the score, the correct answer number, and the exercise number.