An inverter circuit is used to perform a function oppositeto that of a rectifier circuit. An inverter converts a supply of D.C input voltage to a Symmetrical A.C. output voltage of a desired frequency and magnitude. This output voltage can be fixed or variable at a fixed or variable frequency. The variable output voltage is calculated by changing the input D.C. voltage, taking the inverter at a constant gain or by changing the gain of the inverter, taking a fixed D.C. input valtage that is gernrally found by PWM contral within the inverter.
Author Archives: Rahul Raikwar
Microwave Transistor in Hindi
Microwave transistor ek non-liner device hai. iske opration ka principle low frequency device ke saman hai lekin iska dimension, process control, heat sinking and packaging alag hoti hai. aadharsh roop se, high geometry and packaging wala transistor use krne se interalectrod capisitor and load idectance ka effect kam padta hai. iron mobolity, bias voltage, emmitter delay time, base transient time , collector transient time and microwave ke ese parameter hai jinko control krke inki performance ko better create kiya ja shakta hai.
Silcon N-P-N transistor, microwave frequency par addictive power supply karata hai. 5dB ke gain ke saath 3Ghz frequency par yeh 5W ki power ko devlop krta hai.
eventually yeh double diffuse epithelcial device hai.
Introduction of Antenna in Hindi
Antenna transducers hote hai. Yeh same frequency pr radio frequency electric current ko electromegnetic (EM) wave mein change kr deta hai. in dono wave ki frequency same hoti hai. Antenna ko ariel bhi kehte hai. Antenna, Conducting Material ka piece hota hai jo wire, rod or radiator hota hai. yeh electromagetic wave ke liye sensors ki taraf kaam krta hai.
Basic Elements of Antenna –
(i) Alternative Current Elements (ii) Short Dipole (iii) Short Monopole (iv) Half Wave Dipole (v) Quater Wave Dipole
Flow Integrity Error
Flow integrity errors refer to missing block of data, may be lost in the network due to its have been delivered to a wrong destination.
Data is sent as data packets across a data network. it is not neccessary that data packets sent by a source to the destination take the same path. packet i goes through nodes A, B and D. packet 2 goes directly from node A to D. Packet 3 goes from A to D through nodes B and C. Flow of these data packets from the source to the destination may be affected in several ways.
Multipoint Connection
A Multipoint (also called multidrop) connection is one in which more than two specific devices share a single link as in a multipoint environment, the capacity of the channel is shared, either spatially or temporarily. If several devices can use the link simultaneously, it is a spatially shared connection. If users must take turns, it is a timeshared connection. in a multipoint connection, the same link is used by many systems where as a dedicated link is requried between any two systems in a point to point connection. Hence multipoint connection requirs less cabling and thereby reduces the cost. Multipoint connection has ease of installation and low cost. These connections are used over fail over and reliable.
z – Transform
The z-transform is a very powerful tool for the analysis of discrete time signals and LTI systems. The z-transform of a discrete-time signal x(n) is defined as the power series
Z[x(n)] = X(z) = SIGMA x(n)z(power)-n …..(i)
where z is a complex variable. This expression is generally referred to as two-sided z-transform.
If x(n) is a causal sequence, x(n) = 0 for n<0, then its z-transform is
X(z) = SIGMA x(n)z(power)-n
This expression is also called a one-sided z-transform.
The equation (i) is sometimes called the direct z-transform because it transform the time-domain signal x(n) into its complex plalne representation X(z).
There are following uses of z-transform as given below —
(i) Stability of discrete time LTI system.
(ii) Causality of discrete time LTI system.
(iii) System behaviour related to the system function of a discrete time LTI system.
Electromagnetic Radiation
Maxwell’s equations predict the radiation of electromagnetic energy from current sources under time varying conditions. Althrough such phenomenon occurs at all frequencies, its relative magnitude is insignificant until the size of the source region is comparable to wavelength. Our main interest is in the radiation of this electromagnetic wave or loss of energy from the system into free space. While transmission lines or waveguides are generally made so as to minimize radiation, antennas are designed to radiate energy as effectively as possible.
The transmitting antennas are devices used in terminating a transmission line or waveguide with the intent of efficiently launching electromagnetic waves into free space and hence they can be considered as source of such waves in space. The radiation of electromagnetic waves from a transmitting antenna to a receiving antenna is of considerable interest. Thus, we are concerned with the analysis of the radiation fields achieved from typical antenna source depicted.
When RF energy is fed into a mismatched transmission line, standing waves take place, Energy is lost or radiated into the space surrounding the line. This process is considered undesired in the transfer of energy to the radiation device. If we examine this process and expand upon it, by separating the ends of the transmission line, that more surface area of the wire is exposed to the atmosphere and enhances the radiation process.
Radiation efficiency of this system is improved even more when the two wires are bent at 90* (right angles) to each other. Now, the electric and magnetic fields are fully coupled to the surrounding space instead of being confiend between the two wire, and maximum radiation results. This type of radiator is known as a dipole. If the total length of the two wires is a falf wavelength, then antenna is called a half-wave dipole.
Power Electronics
Power electronics is a subject that concerns the application of electronic-principles into situations that are rated at power level rather than signal level. It may also be defined as a subject that deals with the apparatus and equipment working on the principle of electronics but rated at power level rather than signal level.
Advantages of power electronics are as follows –
(i) High reliability of power-electronic converter systems.
(ii) High efficiency due to low loss in power-semiconductor devices.
(iii) Fast dynamic respones of the power-electronic systems as compared to electromechanical converter systems.
(iv) Small size and less weight result in less floor space and therefore lower installation cost.
Engineer's Stuff 