[sdiy] 324 problems

[Ken Stone]

Look here:
http://198.164.142.50/~cgs/modules/mixer.html
an LM358 is half of an LM324.

You have two obvious errors. You must have an input resistor too. Also, the
non-inverting input must be mid way between the two power pins, voltage
wise. If you are using a single 9v battery, you must run to resistors (10k
for example). One connects to the +ve of the battery, and the non-inverting
input. The other goes to the -ve of the battery and the non-inverting input.
The non-inverting input is then considered to be "ground" while the battery
is supplying + and - 4.5 volts with respect to ground.

Ken  


>hey all you vets and smart guys ive got a problem with something, ive been 
>trying to make some simple stuff with a 324 quad op-amp but running into 
>problems with the chip. The simplest design ive tried to make is a simple 
>inverting amplifyer. As far as i know to do this you take the noninverting 
>imput of the amp and ground it. then you hook the signal up to the inverting 
>input then put a little feedback loop with a resistor, the larger the resistor 
>the more the gain (up to the max power). Then of course you have to power the 
>op amp to do this i use a 9 volt battery, the 324 is supposed to be able to 
>work without a polarized power supply so i just hook the positive of the 
>battery with the positive in pin of the amp and the negative with the ground 
>pin. depending on which of the 4 internal amps i use i either get a very quiet 
>sound or just noise. What am i doing wrong? or is my chip just screwed?
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au  
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