So I am trying to build a circuit that I can talk into the condensor mic and hear my voice out of the 8ohm 2 watt speaker.
I am using an audio amplifier chip LM386N 400mW
I have a 220 uf capacitor 15 volts connected from pin 1 to pin8
pin 2 is connected to ground
pin 3 is connected to mic + side
pin 4 is GND and is connected to ground
pin 7 is bypass and is not used at all
pin 6 is Vs which is connected to the + side of an 9 volt battery
pin 5 is output and is connected directly to one side of a capacitor ---then the one side of the speaker and the other side of speaker to ground.
I cann't hear anything.
So the only thing it could be is that I am not using a correct capacitor value infront of the speaker or I am not amplifing the current/voltage enough ?
8ohm 2 watt speaker => 1/2 amp current needed
When I measured the current between the speaker and the output pin taking the inbetween capacitor out I got approx 0.32 amps for the reading in current. (but maybe I measured wrong all try again tommarow and also measure voltage )
WTF is wrong or what am I over looking?
Thanks for any help.
And please don't refer me to a scheme digram for an intercom.
I know how to build everything from a scheme but I wanted to build it from the bare minium just using a few capacitors , and the chip. And I am more curious on why it is not working.
I am thinking I am not using the correct capacitor value in front of the speaker because I can hear the speaker siss sound a little but when I talk into it nothing changes.
Also I am still shakey on LM386 saying the output power is in the mW. It say's something like Vs=6V RL = 8 ohms
Pout= 125mW f = 1kHz Min = 250mW typical = 325 mW
But if my calculations was right then if I have current at .32 A then this means if the typical output power = 325mW
I would have to have a voltage = 325mW/.32A.
And from a 8 ohm 2 watt speaker => 1/2 A for current => Volts = 8ohms * 1/2A = 4 volts needed.
So I am assuming the voltage is the only problem and bumping that up to 4 while keeping the output current that I have would create around about 2 watts.
So then it should work then correct me if I am wrong in anything I said?
If so then it is just a question of creating a voltage tripler or something after the capacitor.
Thanks again and sorry for the long thread
I am using an audio amplifier chip LM386N 400mW
I have a 220 uf capacitor 15 volts connected from pin 1 to pin8
pin 2 is connected to ground
pin 3 is connected to mic + side
pin 4 is GND and is connected to ground
pin 7 is bypass and is not used at all
pin 6 is Vs which is connected to the + side of an 9 volt battery
pin 5 is output and is connected directly to one side of a capacitor ---then the one side of the speaker and the other side of speaker to ground.
I cann't hear anything.
So the only thing it could be is that I am not using a correct capacitor value infront of the speaker or I am not amplifing the current/voltage enough ?
8ohm 2 watt speaker => 1/2 amp current needed
When I measured the current between the speaker and the output pin taking the inbetween capacitor out I got approx 0.32 amps for the reading in current. (but maybe I measured wrong all try again tommarow and also measure voltage )
WTF is wrong or what am I over looking?
Thanks for any help.
And please don't refer me to a scheme digram for an intercom.
I know how to build everything from a scheme but I wanted to build it from the bare minium just using a few capacitors , and the chip. And I am more curious on why it is not working.
I am thinking I am not using the correct capacitor value in front of the speaker because I can hear the speaker siss sound a little but when I talk into it nothing changes.
Also I am still shakey on LM386 saying the output power is in the mW. It say's something like Vs=6V RL = 8 ohms
Pout= 125mW f = 1kHz Min = 250mW typical = 325 mW
But if my calculations was right then if I have current at .32 A then this means if the typical output power = 325mW
I would have to have a voltage = 325mW/.32A.
And from a 8 ohm 2 watt speaker => 1/2 A for current => Volts = 8ohms * 1/2A = 4 volts needed.
So I am assuming the voltage is the only problem and bumping that up to 4 while keeping the output current that I have would create around about 2 watts.
So then it should work then correct me if I am wrong in anything I said?
If so then it is just a question of creating a voltage tripler or something after the capacitor.
Thanks again and sorry for the long thread
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