A Bourdon tube adapted for connection to a source of fluid pressure operates both a mechanically driven gauge pointer and an optical-electronic transmitter for providing operatively parallel output signals corresponding to values of pressure incurred by the fluid source. Simultaneously operative from the displaceable end of the Bourdon tube are both a mechanical movement for effecting amplified displacement of the pointer relative to a dial plate and an opaque vane displaceable within the transmitter between a photoemitter and a pair of photosensors. Circuitry in the transmitter responsive to discrete changes in light interruption between the vane and one of the photosensors emits a signal current corresponding to the pressure value at any given position of the vane.

Combined pressure gauge-transmitter

A high resolution tachometer device is described which can monitor transient speed changes of the order of 0.1% centred around a steady-state, nominal speed in the range 12 · 56 to 209 · 44 rads−1. Unlike existing designs, the unit employs electronically adjusted pulse counting to maintain a constant percentage error over a wide speed range. The device is microcomputer based and includes an optical shaft encoder and a custom developed interface card. The counting mechanism is totally hard-wired to minimize the sampling time. Furthermore, inexpensive hardware addressed by a software program makes the entire speed measuring process automatic and virtually instantaneous. Tests have shown the device to possess a better response time than previous designs.

High resolution adaptive tachometer for spindle motor drives

Position detectors which use the lateral photo effect are used for position detection and positioning on a X-Y-Z stage. Lasers (He-Ne, 632.8 nm) are used as light sources, and position sensing devices are used as light receptors. These devices are applied to absolute position detection on the X-Y-Z stage and to pattern recognition. >

The motor driving control of X-Y-Z table utilizing photoelectric device and optical pattern recognition

An embodiment of the present invention includes a display device including a mechanical indicator, a reference photodetector, a measurement photodetector, and an opaque shroud. The opaque shroud is connected to the mechanical indicator to variably cover the measurement photodetector based on a position of the mechanical indicator. The opaque shroud does not cover the reference photodetector.

Self-powered optical detector for mechanical gauge instruments

A digital accelerometer is realized using a microprocessor. An algorithm is used to calculate the derivative of an ac tachogenerator signal. For the calculation of each acceleration value 20 angular speed samples are used by this algorithm. An automated torque-speed curve tracer controlled by the microprocessor is developed using this digital accelerometer.

Microprocessor-Based Digital Accelerometer and its Application in an Instrument for Motor Torque-Speed Characteristic Display During the Transient Interval

A silicon solar cell is used for an optical sensing of displacement in an analog form The sensor consists of a set of lamp and cell with a lamp-control circuit, where a shutter interrupts the light beam The principle of operation, linearity, temperature effect, frequency response, and associated circuit design are described Experimental results on the characteristics of the cell and the sensing circuit are presented A linearity of ±05 percent and a temperature coefficient of 90 ppm/°C are obtained on the simple set An application to a pressure gauge is also given

Analog Sensing of Displacement Using Silicon Solar Cell

An optical tachometer is developed by the analog processing of the signals obtained from the silicon solar cell displacement sensors. Differentiating the speed signal, satisfactorily smooth acceleration signal is obtained by simple filtering. The torque-speed curve plotting for small motors by the application of this technique and the effects of the filtering on the plot are described.

Haruo Shintani

Papers

Analog Sensing of Displacement Using Silicon Solar Cell

Analog Signal Processing for Tachometer, Accelerometer, and Torque-Speed Curve Plotting of Motors by Use of Silicon Solar Cells