Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

substitute of ic in the given circuit

Status
Not open for further replies.

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
Hello sir
here is the circuit diagram with component details

room-recorder-circuit-diagram.jpg

Can i use some other ic in place of the labelled one ? 741 will work in place of it or any other ic please suggest cause i am unable to get the given
 

pjmelect

Advanced Member level 2
Joined
May 13, 2012
Messages
537
Helped
125
Reputation
250
Reaction score
121
Trophy points
1,323
Activity points
4,687
A 741 should work here, if you use a 741 you should reduce the 68K resistors to say 4.7k.
 

kvtal

Member level 3
Joined
Sep 19, 2009
Messages
64
Helped
5
Reputation
10
Reaction score
5
Trophy points
1,288
Location
india
Activity points
1,583
741 is the best option,for the next stage use lm386 for audio amplification
lm386-200.gif
 

honey 77

Advanced Member level 4
Joined
Jun 29, 2012
Messages
100
Helped
17
Reputation
34
Reaction score
17
Trophy points
1,298
Activity points
1,761
Better option you can go through LM741 op amp only,it can be work in that circuit.
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
thanks to all of you sir , :)
is it possible to use 810 in place of lm386 ?
 

kvtal

Member level 3
Joined
Sep 19, 2009
Messages
64
Helped
5
Reputation
10
Reaction score
5
Trophy points
1,288
Location
india
Activity points
1,583
ya of course u can use tba810 in place of lm386
but circuit may be change
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
810 is audio amplifier ic


ya ya sir sure . . i know the design for now & let me proceed on it first then we gonna move for the compactness
 

kvtal

Member level 3
Joined
Sep 19, 2009
Messages
64
Helped
5
Reputation
10
Reaction score
5
Trophy points
1,288
Location
india
Activity points
1,583
for this ic u need to keep a heat sink
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
ya sir i am using 810 with a built in heat sink on both sides but now the total system is working properly too & 741 is o.k. with 810 except that its procing a strong humm hence output sound with a flanzing effect too . why it so happening ? what can we do ? . . i am operating on 9v 250mA supply here
 

tpetar

Advanced Member level 5
Joined
Sep 27, 2010
Messages
6,427
Helped
1,713
Reputation
3,456
Reaction score
1,678
Trophy points
1,393
Location
Pancevo-Belgrade, Serbia
Activity points
37,372
Obvious not good replacement. :wink:

You can do to make this circuit on right way, or if you whant to redesign it use adequate parts replacement or even redesign whole circuit, but in that case posted circuit is out of story.
 

SunnySkyguy

Advanced Member level 5
Joined
Sep 26, 2007
Messages
6,980
Helped
1,709
Reputation
3,416
Reaction score
1,697
Trophy points
1,413
Location
Richmond Hill, ON, Canada
Activity points
51,518
Check your voltages and report if you cannot fix your connections.

pin 7 = 9 ~ 9.5V = Vbat=V+
pin 4 = 0V = V-
pin 3 = V+/2 ~ 4.5V
pin 2 = same as pin 3 = V+/2 ~ 4.5V
pin 6 = output = same as pin 3 ~4.5V
Check Electret polarity of mic ~ anywhere between 2 ~ 7V .. 4.5 is ideal and you can adjust 10kΩ to achieve more or less offset.

If this is not what you get , it is wired wrong, or at least one part is bad.

You can increase 10KΩ feedback for more gain... e.g. 100KΩ (20dB) 1MΩ (40dB) but bandwidth may be reduced to 10KHz or so (ballpark) depending on GBW product.. i.e. 1MHz / 100 = 10KHz BW
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
no sir i am getting diffrent results on all the pins & got mismatched values with the one u gave .
sir please first of all let me have the proper 9volts constant proper power supply please . .
the adapter i am using is labelled 9 volts 250 mA but i am measuring between the two terminals in open circuited condition it is showing 14.50 volts :( i just checked it out .Too i am operating 810 i.c. on the same voltage connecting parallely with the line . . please help me to maintain the proper one so as to get the the results on each pin as u defined . .thanks

- - - Updated - - -

SunnySkyguy its a kind request to you - please read what i ve mentioned here & help in splving the problem .. thanks

- - - Updated - - -

I ve a lm317t i.c. for now so how can i use it to maintain the proper voltages ? please explain with circuit diagrams too . thanks
 

SunnySkyguy

Advanced Member level 5
Joined
Sep 26, 2007
Messages
6,980
Helped
1,709
Reputation
3,416
Reaction score
1,697
Trophy points
1,413
Location
Richmond Hill, ON, Canada
Activity points
51,518
your schematic indicates a battery, but if you use a 9V wall adapter will normally read ~40% higher but yours is 61% over.

As long as AC ripple is low, it does not matter.

Vin+ = Vin- = Vout = V+/2 = 7.2V in your case.

Report back your voltages.
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
yaa sir , okk i solved the problem of humming & all that thing & the voltage rating at pin 3 & pin 6 is same as you told but they are a liltle bit larger as we already know its due to power supply .
The main variations i did hear is rebuild the pre amp & main audio amp very closer to each other on the practice board & tried to keep the grounds very nearer to each other as it is likely to be on a short lenght same ground line & the results wondered as i gone through internet for some studies on old taperecorder etc circuits , sir thanks a lot to you , without your help i was unable since months :)
sir kindly explain me bandwidth here & too please explain me to control power supply viz lm317t thanks

- - - Updated - - -

presently i am getting here
pin 2 - 7.70v
pin 3 - 8.85v
pin 6 - 13.35v
pin 7 - 14.05v

- - - Updated - - -

sir too if i want to increase the sensativity of microphone so as to capture from a liltle long distance what ll i ve to do then ?
shall i use one more stage of pre - amp or anything else ?
please comment . . .thanks
 

kvtal

Member level 3
Joined
Sep 19, 2009
Messages
64
Helped
5
Reputation
10
Reaction score
5
Trophy points
1,288
Location
india
Activity points
1,583
no if u add one more stge u will again get noise
 

SunnySkyguy

Advanced Member level 5
Joined
Sep 26, 2007
Messages
6,980
Helped
1,709
Reputation
3,416
Reaction score
1,697
Trophy points
1,413
Location
Richmond Hill, ON, Canada
Activity points
51,518
If the resistor values are correct the input bias current is exceeding spec and indicated damaged IC

presently i am getting here
pin 2 - 7.70v
pin 3 - 8.85v << sets the voltage for pin 2 & 3 but shud be 7V
pin 6 - 13.35v
pin 7 - 14.05v
 

rajaram04

Advanced Member level 3
Joined
Jun 17, 2012
Messages
866
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
earth
Activity points
7,644
kk so how to set the voltage for pin 3 now ? please get me the right way
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top