-Explain, how the circuit works? -In what direction current flows? -Current Acro

Question

-Explain, how the circuit works?
-In what direction current flows?
-Current Across Bjts?
-In what mode bjts work ?
Please explain all the above

SPI SP2 C3 04 Push to talk R1 C2 Parts: R1 , R3 , R4 , R6 1K 1/4H Resistors R2,R5---_--1M 1/4W Resistors C1 . C6 1000?F 16 or 25V Electrolytic Capacitors C2,C5----47pF 50 or 63v Ceramic Capacitors C3, C4 220nF 63V Polyester Capacitors Q1.Q4--BC547 45V 100mA NPN Transistors Q2.03- Transistors BD678 60V 4A PNP Darlington SPDT Pushbuttons (or SW1. SW2--_-. toggle/slide switches. see Notes) SP1, SP2----8-100 Ohm Loudspeakers (See Text and Notes) B1, B2___---6V Batteries (See Text and Notes

Explanation / Answer

This circuit is two-way intercom circuit.

OPERATION:

Q1 Q2 and Q3 Q4 are directly coupled NPN and PNP Darlington pair audio amplifier. One part of the circuit acts as Transmitting section and Other parir acts as receiving side. Pushing on SW1, transmitting station operates the audio amplifier whereas the receiving station provides power to transmitting station via loudspeakers.

The human voice is captured on Pushing SW1, this generates an audio signal according to audio voltage. C1 and C3 capacitors block the DC voltage levels in AC input signal. C2 is bypass capacitor. The circuit is operated by B1 and B2. The resistors R1 and R2 provide the bias voltage at the base of Q1. R3 is the bypass resistor used for stable DC bias for Q2. Q2 is the current amplifier emitter follower configuration. The voltage gain occurs at Q1 and Current gain occurs at Q2. this stage boosts current at output followed by the previous stage boost the voltage level. Hence the overall effect will be higher output power and increase voltage swing at the output. The output is taken from the emitter of Q2 via loudspeaker.

The audio signal from the loudspeaker1 of stage one is received through pushing the SW2, The same process occurs in the other stage. The output of Stage two is sent via loudspeaker2, Stage one receives audio input from loudspeaker 2. this circuit passes the audio signal from one station /side to another.

current flows from SW1 to loudspeaker1. and Sw2 To loud speaker2

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.