Optical

I designed this test the concept of using light techniques to send identification data instead of RF. A more detailed discussion on this scheme can be found in the Imagineered new products section...

This battery powered circuit will work from DC to 500KHz. It is designed to connect to an oscilloscope to monitor the light level changes and modulated signals...

The circuit in Figure 1 eliminates the need for adjustments. The circuit uses dc-coupled feedback to control the current in the output resistor. Hence, the output voltage is predictable and constant...

The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode. Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions. It is a great circuit when you want to extend the range of an optical remote control transmitter...

A pair of LEDs having different wavelengths can supply the stimulus for a rudimentary spectral analysis during quality-control sorting operations. By measuring the reflectance of each LED, the circuit in Fig 1 can provide information about the spectral response of the object under test...

The Sun-Up Alarm can be used to provide a audible alarm for when the sun comes up or it can be used in a dark area and detect when a light comes on. It can also be used to detect a light beam, headlights etc. The circuit works as follows. The phototransistor is very sensitive to light. (Any phototransistor will work fine) The sun shining on this device will provide a high to one of the NAND gates. This will cause another NAND gate to oscillate which will drive another gate to output a 100hz tone. The transistor provides drive for the speaker...