what does this mean - Page 3 - Electronic Circuits Projects Diagrams Free

AllVol · 13th August 2006, 01:34 AM

Here is photo I just made of exactly the same amp as we are talking about. I use it with my AM-FM tuner. It is the device on perfboaard on the top left of the tuner. As you can see, I am using only an input cap (the light blue one) and an output cap. It drives speakers with all the volume I want, and more than my wife and others in the house want.

Some day, when I get to it, it will be put inside the tuner case.

Believe me, your circuit will work.

Electro-Ghost · 13th August 2006, 01:58 AM

what about the disc cap
is that the .05 uf one because i used a polyester caps that is green and the condenser mic i got is a condenser mic element is that ok?

AllVol · 13th August 2006, 03:05 AM

Hi Ghost,

Yes you should be okay with all. The 386 is very forgiving... maybe that's why I like it so well. The little disc cap is just a by-pass. You'll notice I didn't even have to use a large cap by-pass on the power rails, although that is a good idea.

Good luck,
AllVol

audioguru · 13th August 2006, 04:22 AM

The LM386 amp circuit won't work with a condenser microphone. It needs an electret microphone that is a condenser mic with a built-in high voltage charge.
Make sure that the electret microphone has two connections because ones with three connections need to be connected differently. The metal case of the mic is connected to its ground wire and the other wire is its output.

AllVol,
With a 9V supply, an LM386 amp delivers only 450mW to an 8 ohm speaker at clipping. My home stereo delivers 70W to 8 ohms or 120W to 4 ohms per channel at clipping.

Electro-Ghost · 13th August 2006, 03:45 PM

my mic has a red a white and a ground

Hero999 · 13th August 2006, 03:46 PM

Connect the red to +V, ground to 0V and the white to the input of the amplifier.

Electro-Ghost · 13th August 2006, 04:04 PM

where does the battery connect to

Electro-Ghost · 13th August 2006, 04:07 PM

donty u mean connect the white to the 1.0 uf

Electro-Ghost · 13th August 2006, 04:12 PM

if i dont use a ground can i just connect all ground sybols to each other

Marks256 · 13th August 2006, 04:34 PM

You need a ground, otherwise it wont work. Also, i don't mean to be rude, but there is no need for double, or even triple posting. If you accidentally forget to add something, there is an EDIT button at the bottom right of your post.

What he means, is you would connect the ground to the ground of the battery, connect the red to the positive end of the battery, and then connect the white to the 1uF. Actually, all of the ground symbols should be connected no matter what. Good Luck!

Electro-Ghost · 13th August 2006, 04:43 PM

in the pic what represents the batt

audioguru · 13th August 2006, 05:17 PM

The datasheet for the LM386 shows an RC network (zobel) at the output to ground to stop it from oscillating when the inductance of a speaker causes a high impedance load at high frequencies.

With your 3-wire electret microphone, remove the 2.2k resistor.

Battery, what battery?? Does the circuit need a battery?? Why??

Hero999 · 13th August 2006, 05:20 PM

The circuit doesn't assume you're running it from a battery. It could be powered from a mains adaptor, a battery or even a solar panel. It's common place to just put power nodes in schematics, in this case connect Vs to the positive terminal and the ground symbol to the negitive terminal.

Electro-Ghost · 13th August 2006, 05:29 PM

do u mean connect all the ground symbols to the negative also, the positive and negative terminals on wat the batt or the chip

wait it just hit me that last post u made. so u mean just connect the gound to the negative of wat ever is powering it and connenct the two Vs nodes to the postative of whatever is powering it right?

Hero999 · 13th August 2006, 05:39 PM

Exactly!

But I'll show you just to be sure.

Drawing circuits with power supply nodes rather than batteries helps save space and make them easier to read.

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13th August 2006, 01:34 AM	(permalink)
AllVol	Here is photo I just made of exactly the same amp as we are talking about. I use it with my AM-FM tuner. It is the device on perfboaard on the top left of the tuner. As you can see, I am using only an input cap (the light blue one) and an output cap. It drives speakers with all the volume I want, and more than my wife and others in the house want. Some day, when I get to it, it will be put inside the tuner case. Believe me, your circuit will work. __________________ All those who believe in psycho kinesis, raise my hand. Last edited by AllVol; 6th February 2007 at 01:48 AM.

13th August 2006, 01:58 AM	(permalink)
Electro-Ghost	what about the disc cap is that the .05 uf one because i used a polyester caps that is green and the condenser mic i got is a condenser mic element is that ok?

13th August 2006, 03:05 AM	(permalink)
AllVol	Hi Ghost, Yes you should be okay with all. The 386 is very forgiving... maybe that's why I like it so well. The little disc cap is just a by-pass. You'll notice I didn't even have to use a large cap by-pass on the power rails, although that is a good idea. Good luck, AllVol __________________ All those who believe in psycho kinesis, raise my hand.

13th August 2006, 04:22 AM	(permalink)
audioguru	The LM386 amp circuit won't work with a condenser microphone. It needs an electret microphone that is a condenser mic with a built-in high voltage charge. Make sure that the electret microphone has two connections because ones with three connections need to be connected differently. The metal case of the mic is connected to its ground wire and the other wire is its output. AllVol, With a 9V supply, an LM386 amp delivers only 450mW to an 8 ohm speaker at clipping. My home stereo delivers 70W to 8 ohms or 120W to 4 ohms per channel at clipping. __________________ Uncle $crooge

13th August 2006, 03:45 PM	(permalink)
Electro-Ghost	my mic has a red a white and a ground

13th August 2006, 03:46 PM	(permalink)
Hero999	Connect the red to +V, ground to 0V and the white to the input of the amplifier. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez And http://www.silicontronics.com, same screen name as here.

13th August 2006, 04:04 PM	(permalink)
Electro-Ghost	where does the battery connect to

13th August 2006, 04:07 PM	(permalink)
Electro-Ghost	donty u mean connect the white to the 1.0 uf

13th August 2006, 04:12 PM	(permalink)
Electro-Ghost	if i dont use a ground can i just connect all ground sybols to each other

13th August 2006, 04:34 PM	(permalink)
Marks256	You need a ground, otherwise it wont work. Also, i don't mean to be rude, but there is no need for double, or even triple posting. If you accidentally forget to add something, there is an EDIT button at the bottom right of your post. What he means, is you would connect the ground to the ground of the battery, connect the red to the positive end of the battery, and then connect the white to the 1uF. Actually, all of the ground symbols should be connected no matter what. Good Luck!

13th August 2006, 04:43 PM	(permalink)
Electro-Ghost	in the pic what represents the batt

13th August 2006, 05:17 PM	(permalink)
audioguru	The datasheet for the LM386 shows an RC network (zobel) at the output to ground to stop it from oscillating when the inductance of a speaker causes a high impedance load at high frequencies. With your 3-wire electret microphone, remove the 2.2k resistor. Battery, what battery?? Does the circuit need a battery?? Why?? __________________ Uncle $crooge

13th August 2006, 05:20 PM	(permalink)
Hero999	The circuit doesn't assume you're running it from a battery. It could be powered from a mains adaptor, a battery or even a solar panel. It's common place to just put power nodes in schematics, in this case connect Vs to the positive terminal and the ground symbol to the negitive terminal. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez And http://www.silicontronics.com, same screen name as here.

13th August 2006, 05:29 PM	(permalink)
Electro-Ghost	do u mean connect all the ground symbols to the negative also, the positive and negative terminals on wat the batt or the chip wait it just hit me that last post u made. so u mean just connect the gound to the negative of wat ever is powering it and connenct the two Vs nodes to the postative of whatever is powering it right? Last edited by Electro-Ghost; 13th August 2006 at 05:34 PM.