Photodarlington Working: The Photodarlington Working shown in (Fig. 20-33) consists of a phototransistor connected in Darlington arrangement with another transistor. This device is capable of producing much higher output currents…
Photodiode Operation and Characteristics: Photodiode Operation - When a pn-Junction is reverse biased, a small reverse saturation current flows due to thermally generated holes and electrons being swept across the…
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…
Programmable Unijunction Transistor: PUT Operation - The Programmable Unijunction Transistor (PUT) is actually an SCR-type device used to simulate a UJT. The interbase resistance (RBB) and the intrinsic standoff ratio…
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…
Silicon Bilateral Switch: It might be convenient to think of a Silicon Bilateral Switch (SBS) as an SUS with a gate terminal, or as a low-current TRIAC. However, the SBS is…
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…