基本信息
摘要：A device for generating and utilizing voltage pulses for determining the revolutions per minute of a rotating shaft or the number of complete cycles per minute performed by a reciprocating or oscillating shaft, having a solid state radiation source, a semi-conductor element sensitive to the radiation and an opaque member having an aperture therein to permit radiation to reach the element for generating a voltage pulse, the opaque element being driven in synchromism with the rotating, reciprocating or oscillating shaft, whereby by fast switching and electronic summation of the voltage pulses the revolutions or cycles can be counted.
摘要附图：
