i am supposed to measure the node voltages around the circuit and then determine the current flowing in the nodes as well as transistors? Can you please tell me the way of doing it .. appreciate it a lot.
How to i analyse this multi-stage transistor amplifier?
analogcircuit analysismultisimoperational-amplifiertransistors
Related Solutions
Yes, the left two transtors each form a oscillator with their particular coil. The two signals are then added. This will cause the amplitude of the signal to go up and down at the beat frequency, which is the frequency difference between the two oscillators.
The oscillator signal with amplitude variations of the beat frequency is "detected" by the circuit around Q3. This makes the signal that is roughly the amplitude envelope of the beating oscillator signal. This is then gained up, rather crudely, by the remaining transistors to eventually drive the speaker.
The system functions by the metal you are trying to detect changing the inductance of one of the coils but not the other. The absolute frequency change is small, but it is made much more obvious by causing a beat frequency between the disturbed coil and the reference coil.
Try this:
simulate this circuit – Schematic created using CircuitLab
It's a simple voltage-follower circuit. The base of Q1 is held at 5.6V by D1, and the emitter is about 0.65V lower, or very close to 5.0V.
It'll deliver almost 2A at 5V, assuming you put a heatsink on Q1 that can handle the 15W of heat produced.
Best Answer
Start by assuming the transistors draw no appreciable base current. Then you find the voltage at the base of Q3. Use the value of R9 to find the current through the emitter/collector of Q3. Assume the inputs are zero and find the currents through Q1 and Q2. Continue the process through the rest of the circuit.