Definition: Peak detector circuits are used to determine the peak (maximum) value of an input signal. It stores the peak value of input voltages for infinite time duration until it comes to reset condition. The peak detector circuit utilizes its property of following the highest value of an input signal and storing it. Rectifier circuits usually provide an output in proportion to the average value of the input. However, some application requires measurement of the peak value of the signal. … [Read more...] about Peak Detector
Vestigial Sideband (VSB) Modulation
Definition: Vestigial Sideband (VSB) modulation is a modulation technique which allows transmission of one sideband in addition with a part or vestige of the other. It is basically a compromise between DSB-SC and SSB modulation. VSB technique was introduced to overcome the drawbacks of SSB modulation. As SSB modulation requires accurate frequency response of the filter to transmit only one sideband completely. Thus by using VSB modulation one can simplify the design of the filter to a … [Read more...] about Vestigial Sideband (VSB) Modulation
Single Sideband (SSB) Modulation
Definition: Single sideband modulation (SSB) is an amplitude modulation scheme in which only a single sideband is transmitted through the channel. It is also known as SSB-SC which is an acronym for Single Sideband Suppressed Carrier as it allows suppression of one sideband and carrier completely. As we know, DSB-SC modulation technique generates an output wave having twice the bandwidth as that of the original modulating signal. So, in order to avoid doubling factor of bandwidth in such … [Read more...] about Single Sideband (SSB) Modulation
Double Sideband Suppressed Carrier (DSB-SC) Modulation
Definition: DSB-SC is an amplitude modulated wave transmission scheme in which only sidebands are transmitted and the carrier is not transmitted as it gets suppressed. DSB-SC is an acronym for Double Sideband Suppressed Carrier. The carrier does not contain any information and its transmission results in loss of power. Thus only sidebands are transmitted that contains information. This results in saving of power used in transmission. This saved power can be inserted into the 2 sidebands. … [Read more...] about Double Sideband Suppressed Carrier (DSB-SC) Modulation
Resistance Thermometer (Resistance Temperature Detector)
Definition: Resistance thermometer is a device that is used to determine temperature by the variation in the resistance of a conductor. It is commonly known as Resistance Temperature Detector (RTD) and is an accurate temperature sensor. RTD is not used for dynamic temperature measurement. Working Principle of Resistance Thermometer As we know, in Resistance thermometer, the resistance of the conductor is dependent on the variation in temperature. When the temperature of the metal is … [Read more...] about Resistance Thermometer (Resistance Temperature Detector)
Sampling Oscilloscope
Definition: Sampling Oscilloscope is an instrument that is used to generate waveform by collecting various samples of an electrical signal. It is basically an advancement of digital oscilloscope having additional features for special purposes. It utilizes the principle of Stroboscopic light technique and is used in order to analyse fast electrical signals. In sampling oscilloscope from various portions of the waveforms, different samples are taken, over consecutive cycles and the overall … [Read more...] about Sampling Oscilloscope
Unijunction Transistor (UJT)
Definition: Unijunction Transistor is a semiconductor switching device having 2 layers and 3 terminals and is abbreviated as UJT. It is called so because of the presence of only one junction. It has the ability to limit large power with a small input signal and is also known as a double base diode. UJT is a device that possesses negative resistance characteristic that means its emitter current rises regeneratively when triggered. Thus an emitter supply is needed in order to restrict it. In … [Read more...] about Unijunction Transistor (UJT)
Methods of Sweep Voltage Generation
As we are aware of the fact that a time base generator does not provide accurate linearity in sweep voltages. Thus various methods of Sweep Voltage Generation are used in order to have a linear output. The methods are discussed below: Exponential sweep circuit The circuit of a basic sawtooth voltage generator is shown below: In the circuit, the position of switch S changes from 1 to 2 thus causing the capacitor to be charged and discharged alternately. Thus an output is achieved that is … [Read more...] about Methods of Sweep Voltage Generation
Time-Base Generator
Definition: The circuit that produces a linearly varying voltage or current with time is known as Time-Base Generator. It is basically a function generator that generates a sawtooth waveform of high frequency. These circuits are also known as sweep circuits. This is so because they are used to sweep the beam of electron across the screen in a horizontal direction in CRO. Types of Time-Base Generator These are basically of two types: Voltage time-base generator: It generates a voltage that … [Read more...] about Time-Base Generator
Clamper Circuits
Definition: Clamper circuits are the electronic circuits that shift the dc level of the AC signal. Clampers are also known as DC voltage restorers or level shifter. Clampers are basically classified as positive and negative that includes both biased and unbiased conditions individually. These circuits are used to clamp an input signal to a different dc level. It basically adds dc component to the applied input signal in order to push the signal to either the positive or negative side. … [Read more...] about Clamper Circuits