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                           We are using 6V , 3W ,500mA power supply ac to dc adapter.



5mm LED:

We are using the LED to see the output instead of connecting the circuit to the home appliance directly.




RESISTORS (all 0.25-watt, 5% carbon):


R1-R3 - 10 kilo-ohm

R4, R6, R15 - 100 kilo-ohm

R5 - 470 kilo-ohm

R7, R12 - 220 kilo-ohm

R8 - 39 kilo-ohm

R9, R10 - 4.7 kilo-ohm

R11 - 1 kilo-ohm

R13, R14, R16 - 470 ohm

RNW1, RNW2 - 10 kilo-ohm resistor network.


The value of the resistors is calculated as shown in the figure below:

E.g. ,

In the figure given below, the first band is black whose value in table is 0.

2nd band is red whose value is 2, 3rd is green whose value is 5 and 4th is silver. Hence the value of resistor is 0210^5 10% equals to 200 kilo-ohm and tolerance =10%.




Capacitors have thin conducting plates (usually made of metal), separated by a layer of dielectric, then stacked or rolled to form a compact device.

Many types of capacitors are available commercially, with capacitance ranging from the picofarad, microfarad range to more than a farad, and voltage ratings up to hundreds of kilovolts. In general, the higher the capacitance and voltage rating, the larger the physical size of the capacitor and the higher the cost. Tolerances in capacitance value for discrete capacitors are usually specified as a percentage of the nominal value. Tolerances ranging from 50% (electrolytic types) to less than 1% are commonly available.

Another figure of merit for capacitors is stability with respect to time and temperature, sometimes called drift. Variable capacitors are generally less stable than fixed types.

The electrodes need round edges to avoid field electron emission. Air has a low breakdown voltage, so any air inside a capacitor - especially at plate edges - will reduce the voltage rating. Even closed air bubbles in the insulator or between the insulator and the electrode lead to gas discharge, particularly in AC or high frequency applications. Groups of identically constructed capacitor elements are often connected in series for operation at higher voltage. High voltage capacitors need large, smooth, and round terminals to prevent corona discharge.




     Air-gap: Air-gap capacitors have a low dielectric loss. Large-valued, tunable capacitors that can be used for resonating HF antennas can be made this way.


     Ceramic: The main differences between ceramic dielectric types are the temperature coefficient of capacitance, and the dielectric loss. C0G and NP0 (negative-positive-zero, i.e. 0) dielectrics have the lowest losses, and are used in filters, as timing elements, and for balancing crystal oscillators. Ceramic capacitors tend to have low inductance because of their small size. NP0 refers to the shape of the capacitor's temperature coefficient graph (how much the capacitance changes with temperature). NP0 means that the graph is flat and


the device is not affected by temperature changes. Low cost and small size, excellent high frequency characteristics and good reliability. Predictable linear capacitance change with operating temperature. Available in voltages up to 15,000-50,000 volts.


       C0G or NP0: typically 1 pF to 0.1 F, 5%. High tolerance and good temperature performance. Larger and more expensive.

       X7R: typically 100 pF to 22 F, 10%. Good for non-critical coupling, timing applications. Subject to microphonics. Temperature up to 125C

       X8R: typically 100 pF to 10 F, 25-100v, 5-10%. Good for high temperature up to 150C

Z5U or 2E6: typically 1 nF to 10 F, 20%. Good for bypass, coupling applications. Low price and small size. Subject to microphonics.

       Ceramic chip: 1% accurate, values up to about 1 F, typically made from Lead zirconate titanate (PZT) ferroelectric ceramic.







The values of the capacitor of this type required:

  33 pico farad

  0.1 micro farad


  Polyester: (PET film): Smaller in size when compared to paper or polypropylene capacitors of comparable specifications. May use plates of foil, metalized film, or a combination. PET film capacitors have almost completely replaced paper capacitors for most DC electronic applications. Operating voltages up to 60,000 V DC and operating temperatures up to 125 C. Low moisture absorption.(from about 1 nF to 10 μF) signal capacitors, integrators.

The values of the capacitor of this type required:

         0.47 micro farad

         0.22 micro farad





Crystal Oscillator (3.579MHz) :