ElectoWorld

Introduction The bipolar transistor is an electronic component of the family of transistors. This component is based on 2 PN junctions, which can either be placed to form an NPN or PNP junction.  To simplify the usefulness of the component, it is possible to specify that the third 3 leg of this component (3-leg component) controls the flow of current between the other 2 legs. NPN Transistor Symbol PNP Transistor Symbol The emitter is identified by the arrow which symbolizes the real direction of the current. Kirchhoff's law applied to the bipolar transistor: IE = IC + IB operations We have previously explained that the base of the bipolar transistor makes it possible to control the passage of current through the component. We have not yet explained that there were 2 operating regimes for this command: saturation region (transistor switching):  in this state the transistor has 2 states:  blocked or on. The state is considered to be blocked when the current no...

A photo-transistor is an electronic component capable of reacting to light by letting current flow. Like transistors, the photo-transistor is designed according to a base, emitter, a collector. But the base is sensitive to light and therefore controls the flow of current through the collector. The photo-transistor is much more sensitive than a photo-diode. A classic photo-transistor-based assembly is the Darlington: a photo-transistor controls a classic transistor, which is very efficient for light barriers or obstacle detection. Phototransistor  Symbol The phototransistor is manufactured most of the time in silicone, but also in other materials (ceramic, and others). The phototransistors are enclosed (generally) in a small opaque or transparent shell, in order to strengthen the light that passes through it and allows light to reach sensitive areas of the phototransistors. How a phototransistor works ? A phototransistor is a transistor whose base B is controlled by the lighti...

Metal-oxide semiconductor field-effect transistor (mosfet) is the second type of field-effect transistor. The mosfet gate is a channel isolated by a layer of silicon dioxide (Si02). The drain and the source are made from substrate materials. they are connected to the gate by a narrow channel. Transistor has type of metals. The first is called the mosfet at depletion and the second is called the   enhancement mosfet (E). The MOSFET transistor is different from the JFET in that the gate is isolated from the channel. Like diodes, these elements are most often made of silicon. They are used to make amplifiers. The enhancement MOSFET In the absence of a control signal at the Gate (Vgs = 0V), the Mosfet is blocked regardless of the type of channel (N or P).Conduction only begins to manifest from a threshold:+ Vth for Drain an N-channel MOS and –Vth for a P-channel MOS. N-channel   enhancement mosfet is a positive voltage applied to the input. The positive charge sticks...