Optoelectronic Devices Articles: Light Units: The total light energy output, or luminous flux (Φs), from a source can be measured in milliwatts (mW) or in lumens (1m), where 1 Im…
Tunnel Diode Parallel Amplifier Circuit: For operation as an amplifier, a tunnel diode must be biased to the center of its negative resistance region. Figure 21-17(a) shows the basic circuit…
Optocoupler Circuit Operation: An Optocoupler Circuit Operation (optoelectronic coupler) is essentially a photo-transistor and an LED combined in one package. Figure 20-35(a) and (b) shows the typical circuit and terminal…
Photoconductive Cell Construction and Working: Photoconductive Cell Construction and Working - Light striking the surface of a material can provide sufficient energy to cause electrons within the material to break…
UJT Circuit Diagram: UJT Circuit Diagram Operation : The Unijunction transistor (UJT) consists of a bar of lightly-doped n-type silicon with a block of p-type material on one side, [see…
TRIAC Control Circuit Diagram: A TRIAC Control Circuit Diagram that allows approximately 180° of phase control is shown in Fig. 19-27(a). The waveforms in Fig. 19-27(b) illustrate the circuit operation.…
SCR Applications Circuits: SCR Applications Circuits : An SCR circuit is stable when it operates correctly: switching on and off only at the desired instants. Unwanted triggering (also called false…
SCR Control Circuit Diagram: Pulse Control - The simplest of SCR Control Circuit Diagram is shown in Fig. 19-8(a). If SCR1 was an ordinary rectifier, the ac supply voltage would…