Definition: An op-amp detector that has the ability to detect the change from positive to negative or negative to a positive level of a sinusoidal waveform is known as a zero crossing detector. More specifically, we can say that it detects the zero crossing of the applied ac signal. It is basically a voltage comparator whose output changes when the input signal crosses the zero of the reference voltage level. Thus it is named so. It is also known to be a square wave generator as the … [Read more...] about Zero Crossing Detector
Basic Electronics
Relaxation Oscillator
Definition: A relaxation oscillator is basically a non-linear oscillator that has the ability to generate a non-sinusoidal periodic waveform at its output. Such as triangular wave, square wave etc. These are also known as non-sinusoidal waveform generators. A relaxation oscillator operates in such a way that it generates oscillations by charging the capacitor and quickly discharging it after attaining a pre-determined threshold voltage. The figure below will help you to understand the … [Read more...] about Relaxation Oscillator
Instrumentation Amplifier
Definition: A special type of amplifier that is used to amplify signals of extremely low-level is known as Instrumentation Amplifier. It is basically a differential amplifier, that performs amplification of difference of input signal. It has high CMMR, offers high input impedance and consumes less power. CMMR stands for common mode rejection ratio, it is the ability to reject unwanted signals. It is also known as data amplifier. Nowadays, it has become an elemental part of modern testing … [Read more...] about Instrumentation Amplifier
Bandpass Filter
Definition: A bandpass filter (BPF) is an electronic circuit that passes a certain band of frequency without attenuation. The particular band of frequency passes by the filter is known as passband. The important parameters that have to be considered in a BPF are the low and high cut-off frequency, centre frequency along with bandwidth and selectivity. Bandpass filters are basically of two types: Active BPF and Passive BPF. An active bandpass filter requires an external power supply and … [Read more...] about Bandpass Filter
Photoresistor – Light Dependent Resistor (LDR)
Definition: Photoresistor is a type of device whose resistance changes with respect to the intensity of the incident radiation. It has a tremendous ability to change its resistance in exposure to light. LDR is an acronym for Light Dependent Resistor. It is a non-linear device. The photoresistor is also termed as the light dependent resistor or photoconductor as it displays the property of photoconductivity. What photoconductivity basically is? It is the phenomenon which improves the … [Read more...] about Photoresistor – Light Dependent Resistor (LDR)
TRIAC
Definition: TRIAC is basically a 3 terminal ac switch that shows conduction in both the directions. These are triggered into conduction by low energy gate signal. TRIAC is a contraction of TRIode for Alternating Current. It is a bidirectional device that belongs to the thyristor family and is basically a diac with gate terminal used to control the turn-on conditions of the device. More specifically we can say in TRIAC, Tri denotes 3 terminals of the device and ac denotes a device that is used … [Read more...] about TRIAC
Voltage Controlled Oscillator (V C O)
Definition: VCO is an acronym for Voltage Controlled Oscillator. It is a device that produces such an oscillating output signal whose frequency can be regulated or altered by the input dc voltage. In other words, we can say, VCO generates an output signal having an adjustable frequency range that is controlled by the dc input voltage. It is a type of oscillator in which the output frequency obtained is the function of the input signal. Usually, the frequency of an oscillator is measured by RC … [Read more...] about Voltage Controlled Oscillator (V C O)
Bistable Multivibrator
Definition: A type of multivibrator whose output consists of 2 stable states is known as Bistable Multivibrator. The circuit switches from one stable state to the other when an appropriate trigger pulse is applied. In a nutshell, in a bistable multivibrator, one stable state can be maintained until a triggering pulse is provided. It is also known as flip-flop multivibrator because due to applied trigger pulses, multivibrator flip from one stable state. And by applying the next trigger … [Read more...] about Bistable Multivibrator
Monostable Multivibrator
Definition: Monostable Multivibrator is a type of multivibrator that has single stable state. MONO means one thus the name itself indicates one state stable and a quasi-stable state. It is also known as a one-shot multivibrator. Here, a triggering pulse is used in order to have transition from a stable state to quasi-stable state. However, no any triggering pulse is provided to have transition from quasi to a stable state. After a pre-determined time interval, the quasi-state returns … [Read more...] about Monostable Multivibrator
Astable Multivibrator
Definition: An astable multivibrator is a type of multivibrator that does not require a triggering pulse thus, sometimes known as a free-running multivibrator. It necessarily provides square wave as its output. Astable multivibrator is called so because both the states present here are unstable i.e., quasi-stable. This means output swings between 0 and 1 and neither 0 nor 1 is the stable state. Here, the successive transition is made from one quasi-state to other after some pre-decided … [Read more...] about Astable Multivibrator