Square wave rotary pulse transducer

Claim 2

An electro-optical pulse generator comprising: a housing; a light responsive means in said housing operable to produce an electric signal; a light source emitting a light beam impinging on said light responsive means to cause the latter to produce said electric signal; means responsive to said signal for providing an output voltage; and a movable light control member between said light source and said light responsive means and having adjacent areas of different light transmitting quality arranged in the direction of its motion including transparent areas which upon reaching the light beam cause the output voltage to trip to high value, opaque areas which upon reaching the light beam cause the output voltage to trip to low value, and semitransparent areas between said transparent and opaque areas that do not cause any change in the output voltage Value thereby to prevent spurious output pulses in the event of slight shifting when said member is stopped at or near the boundary of a transparent of opaque area.

Claim 3

The invention defined in claim 1, wherein said light source is a light emitting diode; and said light responsive means is a photo-transistor.

Claim 4

The invention defined in claim 1, wherein said movable light control member comprises: a flat disc having said transparent, opaque and semi-transparent areas arranged around its periphery; a shaft on which said disc is mounted so that its periphery rotates in said light beam; and means for continuous 360 degree mounting said shaft for rotation in said housing.

Claim 5

The invention defined in claim 1, wherein: said transparent areas transmit 95 percent or more of the light; said opaque areas transmit 5 percent or less of the light; and said semi-transparent areas transmit 35 to 65 percent of the light.

Claim 6

The invention defined in claim 4, wherein: said output voltage means trips to high voltage value in response to 77 to 82 percent light transmission; and said output voltage means trips to low voltage value in response to 23 to 18 percent light transmission.

Claim 7

The invention defined in claim 1, wherein said light responsive means and said light source comprise: a photo-transistor and a light emitting diode mounted in spaced apart relation on a printed circuit board to provide space therebetween for passage of said movable light control member; and means for clamping said printed circuit board in fixed position within said housing.

Claim 8

An electro-optical pulse generator comprising: a housing having a cover; a printed circuit board clamped in said housing by said cover; a light source and a light responsive element mounted on said printed circuit board in spaced apart relation so that the light beam from said light source normally impinges on said light responsive element; an electrical connector mounted on said housing; means connecting said light source and said light responsive element through said printed circuit board and said electrical connector to an external trip circuit for providing an output voltage; a rotary shaft journaled in said housing; a disc mounted on said rotary shaft so that its peripheral portion moves in said light beam; transparent and opaque areas on said peripheral portion for interrupting said light beam as said disc rotates to cause tripping of said external circuit to provide a square wave voltage output; and semi-transparent areas between said transparent and opaque areas that increase the angular distance between the high and low voltage trip points to prevent generation of spurious pulses in the event of slight motion after stopping of said disc.

Claim 9

An electro-optical pulse generator comprising: a housing having a cover; a printed circuit board clamped in said housing by said cover; a light source and a light responsive element mounted on said printed circuit board in spaced apart relation so that the light beam from said light source normally impinges on said light responsive element; an electrical connector mounted on said housing; means connecting said light source and said light responsive element through said printed circuit board and said electrical connector to an external trip circuit for providing an output voltage; a rotary shaft journaled in said housing; a disc mounted on said rotary shaft so that its peripheral portion moves in said light beam; transparent and opaque areas on said peripheral portion for interrupting said light beam as said disc rotates to cause tripping of said external circuit to provide a square wave voltage output; and semi-transparent areas between said transparent and opaque areas that increase the angular distance between the high and low voltage trip points to prevent generation of spurious pulses in the event of slight motion after stopping of said disc.

Claim 10

The invention defined in claim 7, wherein: said transparent areas pass almost all of the light; said opaque areas block almost all of the light; and said semi-transparent areas pass about 50 percent of the light and more or less but not enough more or less to reach the high and low trip points of said circuit.