Need Help In Understanding The Circuit Diagram

@randypang-gvo6Cm • Oct 24, 2024

Oct 24, 2024

1.0K

Hey, i need help in understanding the function of each components in the circuit or how it works.

#-Link-Snipped-#

Any help here would be greatly appreciated.😀

thanks.

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JAIHO

@jaiho-Hz9Ulk • Mar 30, 2009

I see a couple of transistors ( NPN AND PNP ) , and 12v power supply. Resistors resist the current.
You need some kind of data sheet to understand the whole diagram , i think..
sorry .
randypang

@randypang-gvo6Cm • Mar 30, 2009

oh sorry, i forgot to put the parts list.

r1r4r7r10 = 3.3k
r8r9 = 27k
r2r3r5r6 = 68k
r11 = 560
c1 = 1000uf / 16v (microfarad)
c2c3 = 22uf / 16v (microfarad)
c4 = 0.47uf (microfarad)
c5c6 = 22nf
t1t2t3t4 = bc547
t5 = TIP112 / KT829
sauravgoswami

@sauravgoswami-UAfTlI • Mar 30, 2009

I think its a pre-amplifier,not sure i will have to check!!!
randypang

@randypang-gvo6Cm • Mar 31, 2009

its a martin siren project. just wanting to know how the circuit operates.
sauravgoswami

@sauravgoswami-UAfTlI • Mar 31, 2009

well,they seem toi be emitter follower circuits,not sure i will have to check
Harshad Italiya

@harshad-ukH5ww • Mar 31, 2009

I think this is more than the Pre- Amlifier Circuit (yes it is) but it Generates Perticular Frequency at the output of Last Transistor and according to that the LS gives output.
reachrkata

@reachrkata-FOcqhH • Apr 1, 2009

Here goes - Refer:<a href="https://en.wikipedia.org/wiki/Multivibrator" target="_blank" rel="nofollow noopener noreferrer">Multivibrator</a>

1) The circuit with T1 and T2 is an Astable multivibrator with frequency is given by 0.721/R3C3
F = 0.5Hz (approx)

2) The circuit with T3 and T4 is also an Astable multivibrator but here R8 and R9 are connected to the output of the first multivibrator instead of 12V. therefore the frequency of the second vibrator would depend on whether input at R8/R9 is 12V or 12V potential divided by R6/R5. The frequency will be higher when output of first vibrator is logic 0, because charging time of R8C5/R9C6 is much faster.
Exact frequencies need calculation.

3) This signal is driven into the speaker.

In a nutshell, T3-T4 generates the Audio frequencies, while the change of Audio frequency is controlled by T1-T2.

- Karthik
randypang

@randypang-gvo6Cm • Apr 3, 2009

hey there reachrkata,

thanks for the explanation of the circuit 😀

how do i get about knowing the frequencies at the transistors (t1,t2,t3,t4).
sauravgoswami

@sauravgoswami-UAfTlI • Apr 3, 2009

I think now it will be easy for you to figure out the circuit and study accordingly!!!
reachrkata

@reachrkata-FOcqhH • Apr 5, 2009

This link should give you an idea of the design procedure of an Astable and also what the frequency is.

<a href="https://www.scribd.com/doc/12862517/Designing-an-Astable-Multivibrator" target="_blank" rel="nofollow noopener noreferrer">Designing An Astable Multivibrator | PDF | Electronic Engineering | Analog Circuits</a>

-Karthik