| 摘要 |
<p>A light intensity sensor includes a variable-voltage opto-electronic generator adapted to deliver to the terminals of a load resistor a voltage varying as a function of the variable light intensity detected by the sensor. A reference voltage generator is connected in series to the non-inverting input terminal of an electronic voltage comparator. One terninal of the opto-electronic generator, which is also and output terminal of the sensor, is connected via a loop resistor to the inverting input terminal of the electronic voltage comparator. The output terminal of the comparator is connected to the input terminal of a current amplifier fed from an external voltage source via the other output terminal of the sensor. The output of this amplifier is connected to the inverting input terminal of the electronic voltage comparator. The sensor provides an output current that varies as a function of the variable voltage generated by the variable-voltage opto-electronic generator.</p> |
