Abstract: A cable loss simulator for a serial digital signal source adapts a constant resistance, bridged-T passive network to simulate the frequency-loss characteristics of a reference coaxial cable. The cable loss simulator is selectively coupled into the output path of the serial digital signal source to simulate the serial digital signal after transmission through the reference coaxial cable. The cable loss simulator has a resistive input section for impedance matching with the serial digital signal source and a bridged-T section with multiple breakpoints to simulate the frequency-loss characteristic of the reference coaxial cable.

Abstract: A differential voltage monitor is shown using a resistive bridge to produce a sample value representing that differential voltage. A portion of the resistive bridge is located on an IC and a portion is external to the IC. The object is to compare the differential voltage with a reference, producing a logic signal at a threshold level. The threshold level serving as a reference and the sample valve representing the differential voltage are made to be equally dependent on the bridge components located on the IC. In this way, any changes in the IC located bridge resistors compared to the bridge resistors located outside the IC are prevented from affecting the measurement.

Abstract: The output of a bridge measurement circuit is sampled at a time when there is no desired, or expected, bridge output signal, and a balance voltage applied to the bridge measurement circuit is automatically adjusted such that the sample bridge output signal is equivalent to a reference output signal. After the bridge is balanced, the balance voltage is automatically modified by a calibration voltage calculated to provide a known change in the sample bridge output signal, and the sample bridge output signal is compared to a reference output to automatically check the bridge measurement circuit gain. The balance voltage may be automatically modified by multiple calibration voltages, and the sample bridge output signal provides an indication of the linearity of the amplifier gain. The sample bridge output signal is monitored after a change in the balance voltage to automatically provide an indication of the bridge measurement circuit filter cutoff frequency.

Abstract: An electronic sensing circuit, which can be used in place of a linear variable differential transformer (LVDT) has four piezoresistor elements in a Wheatstone bridge configuration. A source voltage is applied across a first pair of bridge points, and the resulting junction voltages appearing at a second pair of bridge points are applied to a pair of inverting amplifiers in balanced configuration which provide first and second output voltages which change relative to each other depending upon the direction and amount of pressure applied to the piezoresistor elements in a manner similar to the output voltages provided by an LVDT.

Abstract: A circuit for measuring variations in the capacitance of a variable capacr forming part of a sensor includes an oscillator which generates an alternating signal which is supplied to two branches of a detection bridge. The first branch includes the variable capacitor connected in series with a variable capacitance diode. The second branch includes a capacitor connected in series with a variable capacitance diode. A differential stage has each of its in puts connected to the common point of a respective one of the branches. Synchronous demodulation means connected to the oscillator, are connected to the output of the differential stage for delivering a DC unbalance voltage Ve which is injected by a feedback line to the common point of the first branch, thereby continuously balancing the detection bridge.

Abstract: A heater control device for an air-fuel ratio sensor which comprises: an air-fuel ratio sensor comprising a sensor element which detects an air-fuel ratio state of exhaust gas of an engine, and a heater which heats the sensor elements; a heater current flow control means for controlling a value of a resistance of the heater to be a target resistance value; a harness having a couple of couplers at both ends thereof which connects between the air-fuel ratio sensor and the heater current flow control means; and a current detecting resistance which is incorporated in the coupler on the air-fuel ratio sensor side, or provided adjacent to said coupler on the air-fuel ratio sensor side, and which is connected to the heater in series and detects current of the heater.

Abstract: A self-contained autonulling bridge circuit based on phase-sensitive deteon of an impedance to be measured is described. The system utilizes a feedback structure to control a variable impedance in order to establish the null of the bridge. The system utilizes a voltage-variable impedance having both resistance and capacitance and provides the phase sensitive relationship in the control means in order to provide highly accurate measurement of an unknown test impedance. The ability to measure small changes in impedance provides particularly useful application to the area of biological sensor impedance measurement or electrochemical impedance measurement using silicon-based devices.

Abstract: In the case of a circuit arrangement with a flow probe operated in a bridge circuit, a device for determining bridge balance, which controls a triggering circuit which can be supplied by an oscillator and controls a switching device for the power supply of the bridge circuit, the oscillator has an operating frequency which is at least approximately inversely proportional to the square of the operating voltage of the power supply.