PHOTO-OPTICAL TRANSDUCER

• US 3,814,935 A
• Filed: 01/24/1973
• Issued: 06/04/1974
• Est. Priority Date: 01/24/1973
• Status: Expired due to Term

• Current Assignee: William R. Kissel
• Original Assignee: William R. Kissel
• Inventors: Kissel, William R.
• Primary Examiner(s): Stolwein, Walter
• Application Number:
  US05/326,330
• Time in Patent Office: 496 Days
• Field of Search: 250/233,206,214R,232,231R,205,231SE,552,573 307/311
• US Class Current: 250/231.14
• CPC Class Codes: G01D 5/26 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
• CPC Class Codes: G01F 1/065 with radiation as transfer means to the indicating device, e.g. light transmission

Abstract

A photo-optical transducer has a light emitting device energizable from a source of electrical potential through a current controlling element whose impedance is varied by a light activated device regeneratively connected with the current controlling element to vary the current drawn by the transducer between a pair of predetermined levels. The luminous output of the light emitting device is modulated by a condition responsive member, as a flowmeter paddle wheel, which is located in the light path between the light emitting device and the light activated device and is displaced in accordance with a parameter of a physical condition, as fluid flow, being monitored thereby.

Claims

1. Apparatus for monitoring the rate of displacement of an element movable in response to a physical condition causing displacement of said element as a function of a parameter of said condition, said apparatus comprising a direct current source of electrical potential, a controllable adjustable impedance in the form of a linear transistor amplifier device having at least a control terminal and a pair of output terminals, an electrically energizable source of radiant energy connected in series with the output terminals of said adjustable impedance transistor device for energization from said source and emitting radiant energy in the path of displacement of said element for modulation thereby in accordance with the rate of displacement thereof, a variable conductivity radiant energy sensor device for receiving radiant energy modulated by said displaceable element and direct current conductively connected between said control terminal of said adjustable impedance transistor device and one side of said potential source for varying the impedance of said adjustable impedance transistor device, and therefore, the current supplied from said potential source in accordance with the rate of displacement of said element, current setting means connected in shunt with said radiant energy sensor device for setting the minimum current drawn by said apparatus, maximum current limiting means connected in series between the other side of said potential source and one of the output terminals of said adjustable impedance transistor device, and a utilization device connected the said one side of said potential source and the junction between said maximum current limiting means and the said one of the output terminals of said transistor device.

2. Apparatus in accordance with claim 1 wherein said minimum current setting means is of high impedance value relative to said maximum current limiting means.

3. Apparatus in accordance with claIm 2 wherein said radiant energy generator is a light emitting device and said radiant energy sensor is a light activated device.

4. Apparatus in accordance with claim 3 wherein said light emitting device is a light emitting diode and said light activated device is a photo-responsive semi-conductor device.

5. The combination in accordance with claim 4 wherein said utilization device is a pulse counting device.