Following our study of amplifiers, we turn to the use of the bjt as a switch, a fundamental element of a digital logic circuit. When using the transistor as a switch, a small base current controls a much larger collector load current when using transistors to switch inductive loads such as relays and solenoids, a flywheel diode is used. Experiment 6 transistors as amplifiers and switches. Physics project report on transistor, action of transistor. If the circuit uses the bipolar transistor as a switch, then the biasing of the transistor, either npn or pnp is arranged to operate the transistor at both sides of the. Both npn and pnp transistors can be used as switches.
This type solid state switching offers significant reliability and lower cost as compared with conventional relays. It is also a very useful circuit for an electronics hobbyist as it can be used as a driver, inverter etc circuit diagram transistor as a switch. As a student of class xii, i did this project as a part of my studies entitled. Transistors that are fully on are said to be in their saturation region. The areas of operation for a transistor switch are kno wn as the saturation regio n and the cutoff. Clap switch a mini project report submitted in the partial fulfillment of degree of bachelor of technology.
When using the bipolar transistor as a switch they must be either fullyoff or fullyon. Touch switch project report free download as word doc. Transistor switches can be used to switch and control lamps, relays or even motors. As a switch is used a relay driven by a transistor which is. In most digital ics transistors will work as a switch to make power consumption very low. During this condition the collector emitter voltage vce will be approximately equal to zero, ie the transistor acts as a short circuit. This component is specifically found on the circuit boards or logic circuits of electronic devices.
Pnp transistors can also be used as switching devices and an example of a pnp transistor switch is shown below. Touch switch project report bipolar junction transistor transistor. Transistor switches can be used to switch a low voltage d c device e. I wrote this article because my nephews often ask me, how do you use a transistor as a switch. This is useful when you want to power a large load using a small physical switch. Introduction equipment the computers of today do not process numbers in the dimm base 10 i. Working of transistor as a switch npn and pnp transistors.
Experiment 6 transistors as amplifiers and switches our final topic of the term is an introduction to the transistor as a discrete circuit element. This is certify that the final project report entitled touch switch submitted summer internship report of the requirement for the degree of diploma, is a work carried out by mahadeb singha, reg no d101169 under my. Switch is a very useful and important application of transistors. Transistors that are fully off are said to be in their cutoff region. Top 10 electronics projects using transistor and mosfet duration. Pdf clap switch a mini project report submitted in the. Then to summarise when using a transistor as a switch the following conditions apply. Since an integrated circuit is constructed primarily from dozens to even millions of transistors formed from a single, thin silicon crystal, it might be interesting and instructive to. This paper presents the design of a clap activated switch device that will serve well in different phonocontrolled applications, providing inexpensive key and at the same time flee from false.
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