I need help in reading this circuit...

[cheris]

I bought this components and solder it up.. but i don't understand how does the circuit works in the diagram... Can someone help me and explain to me?

 

[audioguru]

It looks like a simple and very old kit.
The IC has a part number that is not used by any semiconductor manufacturer so it is a special number used only by the kit maker. We don't know what it is for.
The ultrasonic transducers do not have a part number for us to see which type and which frequency they are used for.

 

[Hero999]

How did you manage to distort the schematic so badly?

I had some fun trying to straighten it out.

 

[Space Varmint]

Judging from the two speakers I would say it's probably a stereo amplifier. It has an IC which might be a DEMUX. Just a wild guess.

 

[Hero999]

Did you read the text?

They're ultrasonic microphones so it can't be a stereo amplfier, besides the schematic doesn't look like a stero amplifier.

T3 is a common emitter amplifier with U2 at its input, not output, which suggests that U2 is a microphone, not a speaker.

U1 is connected to the output of another common emitter amplifier (T2) which suggests it's a speaker but the text says it's a microphone.

The IC could be anything, I couldn't find the datasheet. How does it get its power supply? Via R2, R7 and P1? That doesn't make much sense, there again we don't know what the IC is.

 

[Space Varmint]

I didn't see any text. I was just winging it.

 

[cheris]

Help me please

using the circuit maker to draw the circuit out.. but can someone explain how does the circuit flows to get the output?

 

[cheris]

hmm the ic is TIP 41B while the transducer is those 2 microphones . 1 of them is transmitting and receiving ..! but i don't know which want is transmitting and receiving..

 

[audioguru]

A TIP41B is a power NPN transistor, not an IC. It is shown connected wrong. I think it is supposed to turn off the LED when an ultrasonic signal is received. It does not need to be a big power transistor since an ordinary little transistor can do the same thing.

The entire schematic is drawn backwards since the input is on the right side instead of being on the left side.

I don't know why it has an ultrasonic microphone that is amplified then the same signal drives an ultrasonic speaker.

The value for resistor R6 appears to be too low.

I cropped the schematic since it was too long and I turned around Q4.

 

[chemelec]

Well looking at the Origional Schematic, I suspect the "IC" is a Filter.
Possibly "Low Pass"

audioguru, We made it home from Chile, just before the earhquake.
Good Pictures of my trip on my website.

 

[audioguru]

Hi Gary,
Boy oh boy are you lucky to leave Chile before the earthquake. Maybe you caused the earthquake?

I see that you like waterfalls and you look like a big seal.
I looked only at the first few hundred photos of Chile.