Mohan's Profile

Smoke Signal

  • Curious Asked on February 11, 2018 in NETWORKING.

    You can use FTP (File Transfer Protocol) for file transfers between such different servers as FTP is platform independent. It is a standard network protocol used to transfer computer files from one host to another host over a TCP-based network, such as the Internet.
    is built on a client-server architecture and uses separate control and data connections between the client and the server.

    • 2 answers
    • 0 votes
  • Curious Asked on March 29, 2017 in ELECTRICAL ENGINEERING.

    It is also known as Ajax-Wyatt furnace and represents an improvement over the core-type furnace discussed above. As shown in Fig., it has vertical channel (instead of a horizontal one) for the charge, so that the crucible used is also vertical which is convenient from metallurgical point of view. In this furnace, magnetic coupling is comparatively better and power factor is high. Hence, it can be operated from normal frequency supply. The circulation of the molten metal is kept up round the Vee portion by convection currents as shown in Fig. 1.15. As Vee channel is narrow, even a small quantity of charge is sufficient to keep the secondary circuit closed. However, Vee channel must be kept full of charge in order to maintain continuity of secondary circuit.

    This fact makes this furnace suitable for continuous operation. The tendency of the secondary circuit to rupture due to pinch-effect is counteracted by the weight of the charge in the crucible. The choice of material for inner lining of the furnace depends on the type of charge used. Clay lining is used for yellow brass. For red brass and bronze, an alloy of magnetia and alumina or corundum is used. The top of the furnace is covered with an insulated cover which can be removed for charging. The furnace can be tilted by the suitable hydraulic arrangement for taking out the molten metal.

    • 2 answers
    • 1 votes
  • A Hysteresis Motor is a synchronous motor with a uniform air gap and without DC excitation. It operates both in single and three phase supply. The Torque in a Hysteresis Motor is produced due to hysteresis and eddy current induced in the rotor by the action of the rotating flux of the stator winding.
    The following illustration shows the basic functioning of a hysteresis motor.

    When supply is given applied to the stator, a rotating magnetic field is produced. This magnetic field magnetizes the rotor ring and induces pole within it. Due to the hysteresis loss in the rotor, the induced rotor flux lags behind the rotating stator flux. The angle δ between the stator magnetic field B


    and the rotor magnetic field B


    is responsible for the production of the torque. The angle δ depends on the shape of the hysteresis loop and not on the frequency.

    Thus, the value of Coercive force and residual flux density of the magnetic material should be large. The ideal material would have a rectangular hysteresis loop as shown by loop 1 in the hysteresis loop figure. The stator magnetic field produces Eddy currents in the rotor. As a result, they produce their own magnetic field.

    The eddy current loss is given by the equation shown below.


    ke is a constant
    f2 is the eddy current frequency
    B is the flux density

    • 4 answers
    • 2 votes
    • 3 answers
    • 0 votes
  • Decimal to binary in C: We can convert any decimal number (base-10 (0 to 9)) into binary number(base-2 (0 or 1)) by c program.

    Decimal Number

    Decimal number is a base 10 number because it ranges from 0 to 9, there are total 10 digits between 0 to 9. Any combination of digits is decimal number such as 23, 445, 132, 0, 2 etc.

    Binary Number

    Binary number is a base 2 number because it is either 0 or 1. Any combination of 0 and 1 is binary number such as 1001, 101, 11111, 101010 etc.

    Let’s see the some binary numbers for the decimal number.

    Decimal Binary
    1 0
    2 10
    3 11
    4 100
    5 101
    6 110
    7 111
    8 1000
    9 1001
    10 1010
    Decimal to Binary Conversion Algorithm

    Step 1: Divide the number by 2 through % (modulus operator) and store the remainder in array
    Step 2: Divide the number by 2 through / (division operator)
    Step 3: Repeat the step 2 until number is greater than 0
    Let’s see the c example to convert decimal to binary.

    int a[10],n,i;
    printf(“Enter the number to convert: “);
    printf(“\nBinary of Given Number is=”);

    Enter the number to convert: 5
    Binary of Given Number is=101

    • 1 answers
    • 1 votes
  • Curious Asked on March 28, 2017 in ENGINEERING.

    key bouncing can be sean on oscliscope or Logic analyzer .
    if you press a key -just once- you will see on the Logic analyzer more than one pulse.
    to over come this you had to use a low pass filter , you can just out a capacitor to gound to filter the small pulses wich follows the main pulse.

    In SW you can make a time window after the 1st pulse in which stop reading.

    • 2 answers
    • 2 votes
  • The three basic elements used in electronic circuits are the resistor, capacitor, and inductor. They each play an important role in how an electronic circuit behaves. They also have their own standard symbols and units of measurement.

    Resistors A resistor represents a given amount of resistance in a circuit. Resistance is a measure of how the flow of electric current is opposed or “resisted.” It is defined by Ohm’s law which says the resistance equals the voltage divided by the current. Resistance = voltage/current or R = V/I Resistance is measured in Ohms. The Ohm is often represented by the omega symbol: Ω. The symbol for resistance is a zigzag line as shown below. The letter “R” is used in equations. Resistor Symbol Capacitors A capacitor represents the amount of capacitance in a circuit. The capacitance is the ability of a component to store an electrical charge. You can think of it as the “capacity” to store a charge. The capacitance is defined by the equation C = q/V where q is the charge in coulombs and V is the voltage.

    In a DC circuit, a capacitor becomes an open circuit blocking any DC current from passing the capacitor. Only AC current will pass through a capacitor. Capacitance is measured in Farads. The symbol for capacitance is two parallel lines. Sometimes one of the lines is curved as shown below. The letter “C” is used in equations. Capacitor Symbol Inductors An inductor represents the amount of inductance in a circuit. The inductance is the ability of a component to generate electromotive force due to a change in the flow of current. A simple inductor is made by looping a wire into a coil. Inductors are used in electronic circuits to reduce or oppose the change in electric current.

    In a DC circuit, an inductor looks like a wire. It has no affect when the current is constant. Inductance only has an effect when the current is changing as in an AC circuit. Inductance is measured in Henrys. The symbol for inductance is a series of coils as shown below. The letter “L” is used in equations. Inductor Symbol Interesting Facts about Resistors, Capacitors, and Inductors The resistance of a material is the opposite or the inverse of the conductivity. The Ohm is named after German physicist Georg Ohm. The Farad is named after English physicist Michael Faraday. The Henry is named after American scientist Joseph Henry. Combinations of capacitors, inductors, and resistors are used to build passive filters that will only allow electronic signals of certain frequencies to pass through.

    This answer accepted by Harsh patel. on March 28, 2017 Earned 15 points.

    • 3 answers
    • 0 votes
    • 1 answers
    • 0 votes
  • Curious Asked on March 27, 2017 in ELECTRICAL ENGINEERING.

    One of the key concerns in the transmission of electricity is the power loss in transmission lines, dissipated as heat due to the resistance of the conductors.

    High-voltage transmission lines are used to transmit electric power over long distances. Normally, high voltage (HV) transmission power lines are made of high voltage (between 138 and 765 kilovolts) conducting lines of copper and/or aluminum.

    Assume the power to be transmitted is P, and the resistance of the transmission line is r.
    If the power is transmitted with voltage V, then the current flow through the transmission line is I=P/V.

    Since P and r are fixed conditions, less power will be lost if high voltages V are used.

    Some students will raise questions like: From Ohm’s law. if the voltage is increased, the current will increase ,too. Why is the current smaller when high voltage is used to transmit the power.

    Textbooks forgot to tell students that the transmission line needs a transformer to step down the voltage.
    And the transformer does not have a fixed impedance. If higher voltage is used to transmit the power, the ratio of the transformer will also change which will change the impedance of the transformer.
    The following applet was developed to help you understand the high power transmission line.

    You can change the Power/Voltage V and resistance r in the transmission line with sliders.
    I will show current flow through the transmission line.
    Z is the total impedance of the transmission line, Zt is the impedance of the transformer.
    N:n shows the ratio of the high voltage transformer (Assume user voltage is 100V).
    Efficiency of the power line is also shown at the right side.

    To lower the losses. High current generate more heat and need thick conductors for transmission. Lowering the current would require lesser quantity of conductor which is economical.

    High current generates more heat and would require materials which not only transmit more current, but also tolerate high temperature. Lesser quantity of conductors means less weight for the towers to support. Therefore, the towers can be constructed with less material and would require less space (This is important specially for the towers in Forest regions as it results in lesser deforestation).

    In short, it is more economical and more efficient to transmit power in low current and high voltage.
    Ref ~ quora

    • 1 answers
    • 2 votes
  • Wireless power transfer (WPT), wireless power transmission, wireless energy transmission, or electromagnetic power transfer is the transmission of electrical energy from a power source to an electrical load, such as an electrical power grid or appliance, without the use of conductors like wires or cables. Wireless power is a generic term that refers to a number of different power transmission technologies that use time-varying electric, magnetic, or electromagnetic fields. In wireless power transfer, a wireless transmitter connected to a power source transmits field energy across an intervening space to one or more receivers, where it is converted back to an electric current and then used. Wireless transmission is useful to power electrical devices in cases where interconnecting wires are inconvenient, hazardous, or are not possible.

    Wireless power techniques mainly fall into two categories, non-radiative and radiative. In near field or non-radiative techniques, power is transferred by magnetic fields using inductive coupling between coils of wire, or by electric fields using capacitive coupling between metal electrodes. Inductive coupling is the most widely used wireless technology; its applications include electric toothbrush chargers, RFID tags, smartcards, and chargers for implantable medical devices like artificial cardiac pacemakers, and inductive powering or charging of electric vehicles like trains or buses. A current focus is to develop wireless systems to charge mobile and handheld computing devices such as cellphones, digital music players and portable computers without being tethered to a wall plug. In far-field or radiative techniques, also called power beaming, power is transferred by beams of electromagnetic radiation, like microwaves or laser beams. These techniques can transport energy longer distances but must be aimed at the receiver. Proposed applications for this type are solar power satellites, and wireless powered drone aircraft.[1][2][3]

    An important issue associated with all wireless power systems is limiting the exposure of people and other living things to potentially injurious electromagnetic fields
    Ref~ wiki

    • 1 answers
    • 1 votes