Physical quantity variation measuring device - applies signal to first input of summating amplifier and after processing to its other input

摘要

The physical quantity varies about a specified value, and is esp. the force appearing during testing in a machine of a shock absorber to which a force is periodically applied. The specified value is electrically derived from the instantaneous test value. At the beginning of measurement a signal representing the physical quantity is applied to a summating amplifier whose output is connected to display units and through an analogue-digital convertor to a comparator. A counter output is connected to the comparator other input. Oscillator pulses are applied to it until the two input patterns coincide. Counter content is inverted and applied through a D/A-converter to the amplifier other input.