Abstract: An operational amplifier comprises a differential amplifying circuit and an output circuit. The differential amplifying circuit comprises a pair of input transistors having control terminals connected to an inverting input terminal and a non-inverting input terminal, respectively. The output circuit is connected to the differential amplifying circuit for amplifying an output signal of the differential amplifying circuit and generating an amplified output from its output terminal. In this operational amplifier, the input transistors are bipolar transistors and other transistors are MOS transistors.

Abstract: A charge pump circuit comprises a plurality of capacitors arranged to charge and discharge for generating a charged-up voltage. An oscillation circuit generates a clock signal to be applied to the plurality of capacitors to alternately charge and discharge these charge-up capacitors. A monitoring circuit detects electrical potentials on at least two of the charge-up capacitors and controls the clock signal. An oscillating condition of the oscillation circuit based on the electrical potentials on the at least two of the charge-up capacitors.

Abstract: A current-measuring circuit is provided which is designed to measure the current flowing through an electric load and a switching transistor. The current-measuring circuit includes a current-measuring device. The current-measuring device includes a current-measuring transistor and a voltage control circuit. The current-measuring transistor is disposed in parallel to the switching transistor and allows the current to flow therethrough that is proportional to the current flowing through the electric load and the switching transistor and that is used to measure the current flowing through the switching transistor and the electric load. The voltage control circuit controls a potential difference across the current-measuring transistor so as to match a potential difference across the switching transistor, thereby achieving the proportion of the current flowing through the current-measuring transistor to the current flowing through the switching transistor and the electric load.

Abstract: An output MOS transistor and a current-detecting MOS transistor are connected commonly at their drains and gates. A gate voltage is fed to the gates of these transistors via signal lines. When the voltage of an output terminal is increased in response to excessive load current, a current-mirror circuit consisting of first and second transistors pulls in current from the signal line to reduce the gate voltage. Thus, the output current of output MOS transistor is limited within a predetermined level. Furthermore, a diode, provided in the signal line, produces a voltage drop equivalent to the base-emitter voltage of first transistor. By the function of this diode, the gate-source voltage of output MOS transistor is equalized with the gate-source voltage of current-detecting MOS transistor. As a result, the same operating point can be set for the output transistor and the current-detecting transistor.

Abstract: An analog switching circuit comprises an insulated-gate field-effect transistor (Q20) having two n-type input-side and outpu-side semiconductor regions (201, 202) and a p-type semiconductor substrate region 203, for controlling conductiveness between an input terminal (IN) and an output terminal (OUT) based on a gate potential. A surge pulse detecting circuit (1020), responsive to an electric potential (Vi) of the input terminal (IN), produces a detection signal of a surge pulse equivalent to a forward bias of a PN junction formed between the semiconductor substrate region (203) and the input-side semiconductor region (201). A substrate potential setting circuit (1010) varies an electric potential of the semiconductor substrate region (203) in response to the electric potential (Vi) of the input terminal (IN) when aby detection signal is produced.

Abstract: A constant-voltage power supply circuit includes a first output device provided in a first power feed line from a dc power supply to a first load. The first output device includes a first voltage control element for controlling an output voltage to the first load. A first control device operates for detecting the output voltage from the first output device to the first load, and controlling the first voltage control element to equalize the output voltage from the first output device with a first predetermined constant voltage. A second power feed line is connected to the first power feed line for feeding electric power to a second load. A second output device provided in the second power feed line includes a second voltage control element for controlling an output voltage to the second load.

Abstract: A first switching element opens or closes a power supply route of an inductive load in accordance with a first driving signal. A clamping element prevents a voltage ot the power supply route from exceeding a first clamp voltage when the power supply route is opened. A second switching element opens or closes the current flow route, provided in parallel with the power supply route, in response to a second driving signal. A rectifying means is responsive to the second switching element to change the clamp voltage to a second clamp voltage when the first switching element is turned off. The second switching element is constituted by a MOSFET. A charging element charges a capacitor of MOSFET.

Abstract: A temperature detecting circuit detects the rise of ambient temperature, using a forward voltage drop across a diode. The temperature detecting circuit comprises a temperature detecting diode whose cathode is grounded, a first constant current supply device connected with the anode of the temperature detecting diode, for supplying a constant current Ia to the temperature-detecting diode, a rectifying diode whose cathode is connected with the anode of the temperature detecting diode, a second constant current supply device connected with the anode of the rectifying diode, for supplying a constant current Ib to the temperature-detecting diode, a comparator, and a transistor. When the voltage at the anode of the temperature-detecting diode is lower than a reference voltage, the comparator produces a high-level signal indicative of overheating.

Abstract: A differential-type data transmitter includes a differential amplifier pair (T1, T2, T4, T6, T8) having a plurality of transistors and receiving a pair of a first input signal and a second input signal. A load (T3, T5, T7) is connected to the differential amplifier pair. A detection circuit (T9, T10, I4, I5, I6, I7) connected to a junction between the differential amplifier pair and the load is operative for detecting whether or not the first and second input signals are outside a common-mode input voltage range with respect to the differential amplifier pair. A first output circuit (T12) connected to the detection circuit is operative for outputting a signal depending on an output signal from the differential amplifier pair. The signal outputted from the first output circuit is set to a given level when the detection circuit detects that the first and second input signals are outside the conmmon-mode input voltage range.

Abstract: A driving circuit for the electromagnetic relay provides a coil of the electromagnetic relay with stepped voltage having a first voltage which is slightly larger than a minimum operating voltage which caused the coil to generate magnetic field capable of closing contacts of the electromagnetic relay and a second voltage higher than the first voltage, in response to a triggering signal to trigger the electromagnetic relay. According to this structure, because the first voltage lower than the second voltage is applied to the coil firstly, the contacts are closed by attracting force of the coil risen gently. As a result, the bouncing of the moving contact can be prevented. In addition, the response time required for the closing of the contacts can be prevented to become long.

Abstract: In an actuation circuit for a stepping motor, one switching element and its associated coil are connected at one connecting point, while the other switching element and its associated coil are connected at another connecting point. A pair of switching circuits and a pair of rectifying circuits are provided between two connecting points. When one of switching elements is changed from an ON condition to an OFF condition, the voltage difference between two connecting points allows the current to flow in a designated direction through the switching circuit and the rectifying circuit combined, thereby releasing the energy stored in the coils.

Abstract: A driving circuit of a pulse motor for use in a vehicle odometer is provided. The driving circuit includes a pulse source for providing drive pulses, in sequence, to a plurality of phase coils of the pulse motor, and a wave-shaper for shaping leading and trailing edges of each of the drive pulses so as to vary at a given rate in plural steps for noiseless smooth rotation of the pulse motor.

Abstract: A pulse signal generated by a car speed sensor is converted to an analog voltage by a F-V converter, and two sawtooth signals are formed by two sawtooth current generators based on the analog voltage. The sawtooth currents are then converted into two triangular wave voltages by two I-V converters. Three-stage function generators change the slope of each of the triangular wave voltages step by step and form an approximated sine wave voltage and an approximated cosine wave voltage. A zero-cross compensating circuit is provided in each of the first stage function generators and adjust the triangular voltage to cross zero point.

Abstract: A bipolar semiconductor integrated circuit for driving a motor and the like wherein a semiconductor pattern and a circuit are so contrived that an erroneous operation will not take place even when a negative potential is applied to the output terminal of the circuit. When a negative potential is applied, there exists a quantitative proportional relationship between a parasitic current of a parasitic transistor and a ratio of the lengths of the collectors. The parasitic current decreases with a decrease in the length of the collector. Therefore, the short side of a transistor in the control circuit is directed to the output transistor to which a negative potential will be applied. By detecting the parasitic current and by adding a current to the constant-current using a current mirror circuit, furthermore, erroneous operation due to parasitism can be completely prevented.

Abstract: This invention provides an illuminating device characterized in that the device comprises a light-transmitting rod for transmitting the light incident on one end thereof toward the otehr end, a diffusion pattern formed on the outer peripheral surface of the rod by adhering a fine powder of high refractive index in the shape of a line extending continuously or discretely axially of the rod, and a transparent protective tube covering the peripheral surface of the rod with a circumferential clearance formed between the rod and the tube, the clearance between the rod and the protective tube being sealed off at opposite ends thereof.

Abstract: This invention provides a branch structure for a rod-type optical transmission line having a quartz rod core, characterized in that two quartz rod branch members bent to a substantially L-shaped form and having a circular cross section are combined together with the axes of longitudinal portions of the members in parallel and with the horizontal portions thereof bifurcated, the combined longitudinal portions being ground to a planar surface each at the opposed faces thereof so as to conjointly form a circular cross section in a predetermined cross sectional area ratio, the combined longitudinal portions being adhered together at the ground planar surfaces, conjointly having the same diameter as the quartz rod core and being coaxially connected to the core at a straight portion of the transmission line. The branch structure of the present invention can divide light for transmission into a branch line at a desired ratio with a reduced transmission loss.