Dc Power Supply Design
Abstract:
The main aim of this assignment is to design a pre amplifier circuit with an NPN transistor to be used in a simple public address (PA) system. The pre amplifier is fed from a microphone that produces an average output voltage of 10 mV rms. The amplifier is to operate over a frequency range of 300 Hz to 5 kHz and should have an adjustable volume control. The expected gain of the amplifier is 100. First we are going to design an amplifier for given specifications, model the operation of the circuit using h-parameter and r-parameter model, use computer aided design software to analyze the circuit performance and demonstrate the working of the circuit by hardware implementation. Then, we will plot the frequency response of the circuit and analyze the effect of the emitter bypass capacitor. Finally we will compare the mid-band gain, bandwidth and lower cutoff frequency obtained from the simulation result and the hardware implementation with the designed values.
Chapter 1
Introduction:
Bipolar Junction Transistor (BJT) is a three terminal device with three regions (Emitter, Base and Collector) and two PN junctions (Emitter-Base junction and Base-Collector junction). Since there are two junctions that means there are four possible ways of biasing a transistor. If both junctions are forward biased then the transistor will operate in the saturation region. If both junctions are reverse biased then the transistor will operate in the cut of region. These two conditions of operation are used when the transistor is needed to work as a switch. To use a transistor as an amplifier, the emitter base junction should be forward biased and the collector base junction should be reverse biased.
Amplifier is an electronic circuit that can amplify signals applied to its input terminal. If an AC signal is given to a transistor amplifier it will produce an AC base current. This AC base current will produce a much larger AC collector current since IC=βIB. The AC collector
The main aim of this assignment is to design a pre amplifier circuit with an NPN transistor to be used in a simple public address (PA) system. The pre amplifier is fed from a microphone that produces an average output voltage of 10 mV rms. The amplifier is to operate over a frequency range of 300 Hz to 5 kHz and should have an adjustable volume control. The expected gain of the amplifier is 100. First we are going to design an amplifier for given specifications, model the operation of the circuit using h-parameter and r-parameter model, use computer aided design software to analyze the circuit performance and demonstrate the working of the circuit by hardware implementation. Then, we will plot the frequency response of the circuit and analyze the effect of the emitter bypass capacitor. Finally we will compare the mid-band gain, bandwidth and lower cutoff frequency obtained from the simulation result and the hardware implementation with the designed values.
Chapter 1
Introduction:
Bipolar Junction Transistor (BJT) is a three terminal device with three regions (Emitter, Base and Collector) and two PN junctions (Emitter-Base junction and Base-Collector junction). Since there are two junctions that means there are four possible ways of biasing a transistor. If both junctions are forward biased then the transistor will operate in the saturation region. If both junctions are reverse biased then the transistor will operate in the cut of region. These two conditions of operation are used when the transistor is needed to work as a switch. To use a transistor as an amplifier, the emitter base junction should be forward biased and the collector base junction should be reverse biased.
Amplifier is an electronic circuit that can amplify signals applied to its input terminal. If an AC signal is given to a transistor amplifier it will produce an AC base current. This AC base current will produce a much larger AC collector current since IC=βIB. The AC collector
References: 1. Theodore F. Bogart, Jefferey S. Beasley and Guilermo Rico (2004).Electronic Devices and Circuits. India: Pearson Education, Inc. 2. Thomas L. Floyd (2005). Electronic Devices. 7th ed. India: Pearson Education, Inc. 3. HyperPhysics (2004) Common Emitter Amplifier,[online] Available at: http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/npnce.html [Accessed: 20th Nov 2011]. 4. Scribd (2006) Common Emitter Amplifier, [online] Available at: http://www.scribd.com/doc/27767944/Common-Emitter-Amplifier [Accessed: 25th Nov 2011]. 5. Visionics (2005) RC Coupled Amplifier, [online] Available at: http://www.visionics.ee/curriculum/Experiments/RC%20Ampr/RC%20Coupled%20Amplifier1.html [Accessed: 1st Nov 2011]. 6. SSIT (2006) Analog Electronic Circuits, [online] Available at: http://www.ssit.edu.in/dept/assignment/aeclabmanual.pdf [Accessed: 5th Nov 2011]. 7. Edutalks (2007) RC Coupled Amplifier, [online] Available at: http://www.edutalks.org/electronics%20lab%20manual%201.pdf [Accessed: 7th Nov 2011].