Skip to main content

PROGRAMMABLE UNIJUNCTION TRANSISTOR







PROGRAMMABLE UJT OR PUT


It is not an ordinary unijunction Transistor. But the V-I characteristics is almost similar to an ordinary ujt.

structure of put
Programmable ujt is a four layer P-N-P-N device with a gate connected directly to the sandwiched N-type layer.

The term "Programmable" is applied because the interbase Resistance Rbb, the intrinsic stand off ratio and peak point voltage Vp as defined in UJT can be programmed to any desired values through external base Resistors Rb1 and Rb2 and the supply voltage Vbb.

WORKING OF PROGRAMMABLE UJT


circuit diagram of put



Figure indicates that the anode-gate Junction is Forward biased when the anode becomes positive with respect to gate. When this occurs, the device is turned ON. The anode to cathode voltage Vak then drops to a low level, and the device conducts heavily until the input voltage become too low to sustain conduction. It is seen that this action stimulates the performance of a UJT. The anode act as Emitter ofthis unijunction Transistor.

SCHEMATIC SYMBOL OF PROGRAMMABLE UJT
circuit symbol put

APPLICATIONS OF PROGRAMMABLE UJT

PUT, because of its superiority over ordinary unijunction Transistors, replaces UJT. PUT is popularly used for Relaxation Oscillators.



Get a Clear view about UNIJUNCTION TRANSISTORS AND RELAXATION OSCILLATORS


Labels:

Comments

Post a Comment

Popular posts from this blog

OP AMP INTEGRATOR CALCULATOR

Enter the Input Voltage,Vin: Volts Enter the Frequency, f: Hertz Enter the Input Resistance, Rin: Ohms Enter the Value of Capacitor, C: Farads Output Voltage, Vout: Volts OP AMP based Integrator Tutorial and Design
Post a Comment
Read more

Using the TLP250 Isolated MOSFET Driver Explanation and Example Circuits

I’ve already shown how to drive an N-channel MOSFET (or even an IGBT) in both high-side and low-side configurations in a multitude of ways. I’ve also explained the principles of driving the MOSFETs in these configurations. The dedicated drivers I’ve shown so far are the TC427 and IR2110. Some people have requested me to write up on MOSFET drive using the very popular TLP250. And I’ll explain that here. The TLP250, like any driver, has an input stage, an output stage and a power supply connection. What’s special about the TLP250 is that the TLP250 is an optically isolated driver, meaning that the input and output are “optically isolated”. The isolation is optical – the input stage is an LED and the receiving output stage is light sensitive (think “photodetector”). Before delving any further, let’s look at the pin configuration and the truth table. Fig. 1 - TLP250 Pin Configuration Fig. 2 - TLP250 Truth Table Fig. 1 clearly shows the input LED side and the receiving photodetector as well...
Post a Comment
Read more

Block diagram of AM transmitter and receiver with explanation

Block diagram of AM transmitter and receiver with explanation AM Transmitter : Transmitters that transmit AM signals are known as AM transmitters. These transmitters are used in medium wave (MW) and short wave (SW) frequency bands for AM broadcast. The MW band has frequencies between 550 KHz and 1650 KHz, and the SW band has frequencies ranging from 3 MHz to 30 MHz. The two types of AM transmitters that are used based on their transmitting powers are: ·          High Level ·          Low Level High level transmitters use high level modulation, and low level transmitters use low level modulation. The choice between the two modulation schemes depends on the transmitting power of the AM transmitter. In broadcast transmitters, where the transmitting power may be of the order of kilowatts, high level modulation is employed. In low power transmitters, where only a few watts of transmitting power are required , low...
Post a Comment
Read more