Relaxation oscillator

About: Relaxation oscillator is a research topic. Over the lifetime, 1952 publications have been published within this topic receiving 22326 citations.

A sub 1V self clocked switched capacitor bandgap reference with a current consumption of 180nA

Abstract: This paper presents a bandgap reference capable of operating at supply voltages below 1V. In contrast to the vast majority of bandgap circuits the multiplication of the proportional to absolute temperature voltage is done by a switched capacitor network. Thus a reduced chip area is achieved. As a clock is needed for the switching, a relaxation oscillator is deeply integrated into the circuit. Combined the circuits provide a continuous sub bandgap voltage reference output of 615mV and a clock signal with a frequency of roughly 53kHz. The overall current consumption is 180nA at room temperature. The circuit is developed in a 130nm CMOS technology and occupies an active area of 0.0132mm2

Mass-flow measuring device

Abstract: 1,028,143. Automatic frequency control systems; frequency modulation. GEORGE KENT Ltd. Aug. 19, 1963 [Aug. 31, 1962], No. 33613/62. Headings H3A and H3R. [Also in Division G1] Two diode pumps feed a common capacitor C4 with opposite polarity pulse inputs, one diode pump pulse input being variable, e.g. in recurrence frequency and/ or pulse amplitude, due to a signal, and the other having its mean frequency determined by an oscillator retroactively controlled in frequency by the output of the common capacitor so that the mean frequency indicates the signal. The input may be an amplitude modulated carrier whose modulating frequency is made proportional to the signal, e.g. a rate of flow of fluid using a magnetic pick-up as in Specification 984,209, and after amplifying at J1 and full-wave rectifying at D1, D2, applied to a bi-stable circuit A1 whose output is a series of rectangular pulses of constant recurrence frequency equal to the modulation frequency. This feeds a mass flow-rate indicator through a diode pump D3, D4 whose pulse amplitudes (strokes) are varied by a temperature sensitive resistor RV1 and a manually set resistor RV2 so that changes in density due to temperature, or in specific gravity, may be allowed for. The D.C. voltage across capacitor C4 may be amplified by a chopper D.C. amplifier J4, A2 with synchronous demodulator J5, to produce a negative D.C. input over capacitor C8 to a bi-stable relaxation pulse generator A3, J6 so that when A3 conducts due to the input its output renders gate transistor J6 conductive to short-circuit the input. C8 is then discharged by a constant voltage (positive) through resistor R14, so that A3 and J6 are again blocked and this continues until, after a delay due to the time constant of R11, C8, which delay is inversely proportional to the voltage input at R11, the bi-stable relaxation oscillator A3, J6 again conducts and the cycle repeats at a frequency proportional to the voltage across C4 until the latter is discharged to zero by the diode pump J3, D5, D6 operated from the relaxation oscillator A3, J6. The variable frequency pulse output from A3 may be frequency divided and applied to counters indicating the total mass flow. The mass flow may be solids or a conveyer belt, its speed producing the proportional modulating frequency and the weight of solids on the belt varying the diode pump pulse amplitude set by RV2. Alternatively, for measuring the heat control of fuel gases, the volume flow can control the modulation frequency and the heat content the diode pump pulse amplitude. The temperature variable resistor RV1 may be in a probe in the fluid being metered.

Tuning apparatus of phase-locked loop type

Abstract: A tuning apparatus of phase-locked loop type having a voltage controlled oscillator which is working as a local oscillator of a tuning circuit, a programmable divider supplied with the output signal from the voltage controlled oscillator, a reference frequency signal generating circuit, a phase comparator supplied with the output signal from the voltage controlled oscillator and the output signal from the reference frequency signal generating circuit, and supplying the output signal to the voltage controlled oscillator, the programmable divider, the reference frequency signal generating circuit and the phase comparator being formed in a single integrated circuit, and a control circuit formed separately from the integrated circuit for supplying a control data to the programmable divider in the single integrated circuit is disclosed, in which the integrated circuit further comprises a memory for memorizing the control data which is serially supplied from the control circuit and supplying the control data to the programmable divider in parallel.

Power supply unit for data viewing devices

Abstract: The invention relates to a power supply unit for data viewing devices, which, from a main alternating voltage produces at least one d.c. voltage for the operation of the data viewing device, where the power supply unit is in the form of a switching power supply unit and contains an oscillator which produces signals which determine the switching frequency of the switching power supply unit and where the data viewing device contains a pulse generator which, in order to produce an image on a screen, produces timing pulses of a given repetition frequency and a given duration. More particularly, the control stage for a switching power supply unit of a data viewing device having a display screen includes a free-running oscillator whose frequency is synchronized by timing pulses from a pulse generator. These pulses are of a predetermined repetition frequency and a given duration. The oscillator is preferably an astable multivibrator. The output signal of the oscillator is pulse modulated and fed to the base of a switching transistor in the power supply circuit. A separator stage such as an optical coupling element or transformer, is provided in the circuit between the pulse generator and the oscillator. The oscillator may contain an amplifier provided with a positive feedback and a negative feedback and which oscillator has its control input connected to the non-inverting input of the amplifier. The non-inverting input of the amplifier preferably includes a capacitor.