UNIT OF MEASUREMENT OF RESISTORS
- 1 Ω
- 1000 Ω = 1 Kilo Ω (1K Ω)
- 1000 KiloΩ = 1 Mega Ω (1M Ω)
What is a resistor ?
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. (Source : Wikipedia)
What is the use of a resistor in a circuit
- FUSE (fusible resistors)
- Resistor to sense temperatures. (Thermal Sensing resistance NTC / PTC Value Decreases with rise in temperature and Value Increases with drop in Temperature)
- Resistor as Current limiting resistor (CLR)
- Use two or more resistor to make a voltage divider
- Vin – ⚡ Input Voltage
- R1 – Resistance 1
- R2 – Resistance 2
What is the use of a resistor in a LAPTOP circuit
Pull up resistors
Pull-up resistors are simple fixed value resistors, that are connected between the voltage supply and the particular pin. These resistors are used in digital logic circuits to ensure a logic level at a pin
Pull Down resistors
Pull-down resistors also works in the same way. But, they pull the pin to a low value. Pull-down resistors are connected between a particular pin on a microcontroller and the ground terminal.
When sufficient forward voltage is applied, a current flows in the forward direction.
A capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance.
UNIT OF MEASUREMENT OF CAPACITOR IS – FARADS
FOR AC ITS LOW RESISTANCE
FOR DC ITS HIGH RESISTANCE
TYPES OF A CAPACITORS USED IN MOTHER BOARD
A polarized (“polar”) capacitor is a type of capacitor that have implicit polarity — it can only be connected one way in a circuit. The positive lead is shown on the schematic (and often on the capacitor) with a little “+” symbol.
Non Polarized Capacitor
A non-polarized (“non polar”) capacitor is a type of capacitor that has no implicit polarity — it can be connected either way in a circuit.
MODES OF CAPACITOR USED IN MOTHERBOARD
ALLOWS ONLY DC TO FLOW
HIGH RESISTANCE FOR AC
LOW RESISTANCE FOR DC
A digital transistor is a transistor that has an internal resistor from the input to the base and a pull up/down resistor between the base and the emitter.
DAP – DRAIN HAS ANODE IN P-CHANNEL
SAN – SOURCE HAS ANODE IN N-CHANNEL
How to Recognize N CHANNEL and P CHANNEL MOSFET
EVEN NUMBER OR ODD NUMBER
DIRECTION OF AN ARROW OF GATE
SAN AND DAP METHOD
In P Channel Mosfet we do not need gate permission to pass current / voltages from Drain to Source. (Voltages passes through a diode with ~0.5 voltage drop)
In N Channel Mosfet we do not need gate permission to pass current / voltages from Source to Drain. (Voltages passes through a diode with ~0.5 voltage drop)
We need gate permission to turn on mosfet in order to pass voltages in reverse bias condition
Conditions to turn on / off mosfet used on laptop motherboards
ON – HALF OF SOURCE VOLTAGE or NORMALLY 0~9V
OFF – SAME AS SOURCE VOLTAGE
ON – ONE AND HALF TIME DRAIN VOLTAGE or NORMALLY 24~28 FOR 19V FOR FULL POTENTIAL
OFF – 0V OR GND OR IF VOLTAGE IS LESS THAN DRAIN OUTPUT IT THERE BUT NOT AT FULL POTENTIAL
In this condition, if the MOSFET is “ON” then the MOSFET will allow current / voltage to flow from Source to Drain Or Drain to Source.
DUAL CHANNEL MOSFETS
Dual Channel mosfets are the type of MOSFETS where two mosfets are placed inside a single IC.
Two mosfets can be of both N-Channel or Both P-Channel, or both of different type.