Introduction to OP­AMPS of electronic components

                     Introduction to OP­AMPS 

• OP – AMP is a high gain voltage amplifier with differential input and single ended output. 
• Working of OP­AMPS: OP­AMP amplifies the difference between the inverting and non inverting input. It works in the open loop mode and closed loop mode. 
• Characteristics of OP­AMP: An ideal op­amp has the following characteristics:

1. Infinite open loop gain 
2. Infinite input impedance 
3. Zero Output impedance 
4. Infinite Bandwidth 

• OP­AMP made of transistors: The diagram shows discrete op amp made of transistors with a gain of 100. This is not widely used.
  
• IC 741: IC 741 is the most common type of op­amp. It consists of differential amplifier, voltage amplifier and output amplifier. 
• IC 741 features : IC 741 has the following features: 

1. Zero common mode gain. 
2. The offset null pins are used to place external resistors. 

• Hybrid: A hybrid op amp consists of three triodes and coupling capacitor at the input. 
• Applications 

1. It is used as low pass or high pass filter. 
2. It is also used in electrocardiogram amplification. 
3. Resistor vs Inductor: Resistor is used to reduce the magnitude of the voltage whereas inductors are used to shift the AC voltage phase.

• Resistor vs Capacitor: A capacitor stores charge whereas resistor uses potential energy to generate power. 
• Capacitor vs inductor: Both capacitor and inductor store energy but capacitor stores it in electric filed whereas inductor stores it in magnetic field. 
• Transistor vs diode: A diode consists of 2 layers whereas transistor consists of 3 layers. A transistor works like diodes placed back to back. 
• Diode vs Zener diode: Diodes can work in both forward and reverse bias but zener diodes are meant to work only in the reverse bias mode. 
• Transformer vs Transistor: A transistor contributes to power gain by taking power from external power supply whereas a transformer is used for impedance matching. 
• Transistor vs op­amp: A transistor needs biasing to turn it on and an op­amp although made up of transistors does not need biasing and can amplify the difference. 
• Simple circuit 

1. A car­ reverse horn. It starts blowing as soon as the car is in the reverse gear. 
2. The circuit of reverse horn consists of resistors, capacitors, transistors and diodes. 
3. A battery of 12 V is supplied to provide power to the circuit. 
4. The power supply passes through the transistor which acts as a switch and provides power to a zener diode. It regulates the current and passes it to the transistors which generate sound waves which are again amplified by another transistor.