Unijunction transistor voltampere characteristics aim. Summary a put programmable unijunction transistor is a 3 terminal 4layer thyristor acting like a unijunction transistor. The simplest of all ujt circuits is the relaxation oscillator producing nonsinusoidal waveforms. Bjts are used as amplifiers or switches, as its main function is to amplify currrent, where as ujt acts as a switch. The circuit calls for a 2n4891 unijunction transistor which is now obsolete and very expensive. Unijunction transistor applications the most common application of a unijunction transistor is as a triggering device for scr and triac but other ujt applications include sawtoothed generators, simple oscillators, phase control, and timing circuits.
The ujt is having three terminals base1 b1, base2 b2 and emitter e. The put is similar to the unijunction transistor ujt, but its intrinsic standoff ratio can be set by two external resistors. Designed to enable the engineer to program unijunction characteristics such as rbb. Programmable unijunction transistorcomputing hardware. Njsemi unijunction transistors,alldatasheet, datasheet, datasheet search site for electronic. The unijunction transistor ujt thyristors electronics. The device hasa unique characteristic that when it is triggered, its emitter current increases re generatively due to negative resistance characteristic until it is restricted by emitter power supply. No licence is granted for the use of it other than for information purposes in connection with the products to. With only one pn junction, the device is really a form of diode. The 2n2646 model is the most commonly used version of the ujt. The 2n3638, 2n3640, and 2n3646 or their motorola mps counterparts are used in other loca tions. Unijunction transistor programmable unijunction transistor triggers designed to enable the engineer to program unijunctioi characteristics such as rbb t. Its has a four layered construction just like the thyristors and have three terminals named anodea, cathodek and gateg again like the thyristors.
As well, it can convert an analog data into digital data. Unijunction transistor has different characteristics from ordinary bipolar transistor. Programmable unijunction transistors put selection guide. Thyristors thyristors are a class of semiconductor devices characterized by 4layers of alternating p and n material. Apr 16, 2012 summary a put programmable unijunction transistor is a 3 terminal 4layer thyristor acting like a unijunction transistor. The unijunction transistor characteristics and applications. What is the difference between a ujt and a bjt quora. Some thyristors and their symbols are a 4layer diode b scr c diac d triac e scs. These devices may also be used in special thyristor. Though it serves a function similar to the unijunction transistor, the put is a three terminal thyristor. Since the device has one pn junction and three leads, it is commonly called a unijunction transistor.
Fourlayer devices act as either open or closed switches. The u ni j unction t ransistor is a threeterminal, twolayer, semiconductor device. The main requirements of a switch to be efficient are to. Introduction to unijunction transistor construction and.
Unijunction transistor programmable unijunction transistor triggers designed to enable the engineer to program unijunction characteristics such as rbb, iv, and ip by merely selecting two resistor values. The nte6402 is a 3terminal silicon planer passivated pnp device available in the standard plasticlow cost to98 and to92 type packages. Nte6402 datasheet12 pages nte programmable unijunction. An ntype unijunction transistor left symbol in above picture is made by implanting a small ptype emitter probe in a bar of ntype silicon. Application includes thyristortrigger, oscillator, pulse and timing circuits. Apr 24, 2017 a unijunction transistor ujt is a threelead electronic semiconductor device with only one junction that acts exclusively as an electrically controlled switc slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. No licence is granted for the use of it other than for information purposes in connection with the products to which it relates. Discrete semiconductor products transistors programmable unijunction are in stock at digikey. In this case the gate terminal is c onnected to the n region but in thyristor or scr gate is connected with p region, thus the anode and cathode constitute the pn junction which controls the on and off states of put. Pulse circuits 5 a switch is a device that makes or breaks a circuit or a contact. Manufacturer and supplier of semiconductors, rectifiers, diodes, transistors, thyristor scrs, triacs, mosfets, igbts, hybrids, solid state relays to the industrial and military market.
I know i can substitute a 2n6028 put that will do the job but i need to know the values of the programming resistors to make the substitution work. The 2n706 or 2n208a are the rf transistors q, q2, and q3. As the name implies, programmable unijuntion transistor, there needs to be a programmed voltage supplied to the gate pin. These devices may also be used in special thyristor application. The terminals are designated as anode, anode gate, andcathode. The terminals are designated as anode, anode gate, and cathode.
New jersey semiconduct 2n, unijunction transistors. This device has been characterized as a programmable unijunction transistor put. Programmable unijunction transistor or put is a close relative of the thyristor family. The ujt is consist of a light doped ntype of silicon bar, there is a heavily doped ptype of region at one side of the ntype of bar. Programmable unijunction transistors put are threeterminal thyristors that are triggered into conduction when the voltage at the anode exceeds the voltage at the gate. Nte6402programmable unijunction transistor putdescription.
Nte6402 programmable unijunction transistor put description. Programmable ujt, put construction, working and theory. Njsemi, alldatasheet, datasheet, datasheet search site for electronic components and semiconductors, integrated circuits, diodes, triacs, and other semiconductors. The motorola house number is simply mps instead of 2n. Bjt is a current controlled device, where as ujt is a voltage controlled device. Among these three transistors, this article talks about ujt transistors working features and its construction in brief. Although the unijunction transistor is listed as obsolete read expensive if obtainable, the programmable unijunction transistor is alive and well. The nte6402 is a 3terminal silicon planer passivated pnp device available in the standard plastic low cost to98 and to92 type packages. Jun 25, 20 the circuit calls for a 2n4891 unijunction transistor which is now obsolete and very expensive. An external resistor network programs the intrinsic standoff ratio is. It is a pulse generator with the trigger or control signal applied at the emitter. It exhibits negative resistance characteristic that makes it useful in oscillator circuits. A unijunction transistor ujt is a threelead electronic semiconductor device with only one junction that acts exclusively as an electrically controlled switc slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Pspice model library includes parameterized models such as bjts, jfets, mosfets, igbts, scrs, discretes, operational amplifiers, optocouplers, regulators, and pwm controllers from various ic vendors. Oct 03, 2017 unijunction transistor is also known as doublebase diode because it is a 2layered, 3terminal solidstate switching device. Unijunction transistors, 2n2160 datasheet, 2n2160 circuit, 2n2160 data sheet. In this circuit the two resistors 15k and 27k provide this programmed voltage by a voltage divider action. Substituting a 2n6028 for a 2n4891 unijunction transistor. Unijunction transistor abbreviated as ujt, also called the doublebase diode is a 2layer, 3terminal solidstate silicon switching device.
Unijunction transistor is also known as doublebase diode because it is a 2layered, 3terminal solidstate switching device. However, i would like to build my own from normal transistors rather than buying one. To draw the voltampere characteristics of the unijunction transistor and to find the ujt pameters. Unijunction transistor the ujt as the name implies, is characterized by a single pn junction. The terminals are emittere, baseoneb1 and basetwob2. This data sheet and its contents the information belong to the members of the premier farnell group of companies the group or are licensed to it. Programmable unijunction transistor put electronic circuits. Since it has only one junction it is called as a unijunction device. Specifically, im trying to emulate the behavior described in the 2n6028 datasheet. Ujt unijunction transistor tutorial power electronics a to z. Unijunction transistor the unijunction transistor ujt is a three terminal device with characteristics very different from the conventional 2 junction, bipolar transistor.
The unijunction transistor characteristics and applications, type numbers 2n4892n494c, 2n16712n1671c, 2n2160, 2n24172n2422b sylvan, t. Similar to this question, i need a replacement for a programmable unijunction transistor put. The 2n2160 is a unijunction transistor and no substitute is. As it exhibits a negative resistance region, it is used as an oscillator and triggering device. The original unijunction transistor, or ujt, is a simple device that is essentially a bar of ntype semiconductor material into which ptype material has been diffused somewhere along its length, fixing the device parameter the intrinsic standoff ratio. Ujt is a threeterminal, singlejunction, twolayered device, and it is similar to a thyristor compare to a transistors.