An electronic circuit which gives an output corresponding to a first input so long as that output is within limits set by a second input. When the output goes beyond these limits, a diode connected thereto is forward biased to establish a high loop gain feedback path holding the output constant.

An electronic tachometer is provided in which the frequency of charge transfer to a capacitor is proportional to the RPM being measured. The d.c. level proportional to the frequency of charge transfer is applied to an amplifier having a feedback resistance and whose output drives a d.c. meter having a number of scales calibrated in RPM. When the meter needle reaches the end of one scale, the value of feedback resistance for the amplifier is suddenly decreased by the effect of a switching circuit...

A fool proof and pocket size electronic thermometer is described that is particularly useful for obtaining oral or rectal body temperatures. The thermometer includes a casing on which is mounted a scale for visually indicating temperature readings. A simplified plug-in connector is used to connect a miniature electrical cord to the casing. Such cord terminates in a disposable semiconductor junction through which a constant current is made to flow so that the voltage developed across it is depend...

An electronic computer having an arrangement for shifting the characters stored in selected registers of the memory is disclosed, wherein the shift of the characters is controlled by an instruction causing a control unit to select the register to be shifted and to activate the arrangement. The arrangement comprises a one-character register which is first connected by the control unit with the last significant stage of the selected register for exchanging the characters stored therein. The one-ch...

An electronic timepiece comprises means for selectively displaying the time including at least one of date, day of the week, hour, minute and second, and means for rapidly adjusting or correcting said displayed time, thus making possible the rapid time correction or adjustment with simple construction, and with minimum operation switches.

An electronic timepiece such as a wrist watch of the type employing all solid state components including an electronic or a liquid crystal output display for indicating time, utilizes a high efficiency up-converter to enable a small physical and low voltage battery to provide energy for the entire electronic watch assembly by applying said battery voltage to an inductor which conducts current under control of a switching circuit. The control of current through the inductor at specified intervals...

An electronic watch with an electronic display of time fed from a counting circuit via a transcoder comprises a data input device including a manual control member for transferring at least one element of displayed data by means of a logical transfer circuit. For example, a number indicated on a separate display by means of a separate counter can be selectively transferred to replace any particular number in the display of time to thereby set the time. Alternatively, an indication of a first uni...

Disclosed is a technique for controlling the format of a number to be read out of a store register in such a manner that symbols can be interlaced with the number. Two registers are used, one register containing the number and the other, the symbols. The two registers are read into a single register which then contains the appropriate symbol-number combination. Also disclosed are techniques for changing from floating point to fixed point notation and techniques whereby the number of digits which...

An electronic watch having a balance wheel formed from two substantially round boards having at least a pair of flat permanent magnets mounted in facing relation on said boards. Said boards have an inertia of not more than 2,500 mg-mm.sup.2, the balance wheel formed from said boards and a hair spring having a frequency of not less than 4 Hz. A two-terminal coil is positioned in the magnetic field defined by said pair of permanent magnets coupled to a driving circuit formed from at least one PNP ...

A key operated electronic lock is disclosed. A serial stream of bits representing coded information is generated when a coded key having a plurality of apertures is moved between a light source and a pair of phototransistors. The serial stream of bits is stored in a shift register, and decoded by means of a decoder circuit which operates a locking solenoid.