Dear all!
I am stuck with a very stupid problem, I am not capable of creating a square wave generator with an operational amplifier 741. The crazy thing is that I have done it many times.
I need a square wave with 50% duty cycle, where every wave lasts 0.5 seconds. I have done the math that matches this online script:
http://img101.imageshack.us/img101/9963/timer.jpg
As a dual power supply, I use 2 9v Batteries with the positive pole of one is connected to Vcc, the negative of the other t o -Vcc and the other poles to the Ground.
My oscilloscope doesn't see anything in the output, independently from the division. Nothing, flat... we lost him
My tester sees a constant tension of -1.7Volt... as if the multivibrator astable is saturated at that value.
Using a dual power supply of ±3volt, there is no change, exept the output of -0.3v, I tried other values of the capacitor as 1microFarad/25Volts a 1microFarad/50Volts, 1microFarad/63Volts, 1microFarad/100Volts and still nothing!!!
I changed the Operational amp. and still nothing.
This is a picture of the board
http://img46.imageshack.us/img46/661/dsc01563b.jpg
Using another board, the same... where the <snip> is the mistake ??!?!?!?
I am stuck with a very stupid problem, I am not capable of creating a square wave generator with an operational amplifier 741. The crazy thing is that I have done it many times.
I need a square wave with 50% duty cycle, where every wave lasts 0.5 seconds. I have done the math that matches this online script:
http://img101.imageshack.us/img101/9963/timer.jpg
As a dual power supply, I use 2 9v Batteries with the positive pole of one is connected to Vcc, the negative of the other t o -Vcc and the other poles to the Ground.
My oscilloscope doesn't see anything in the output, independently from the division. Nothing, flat... we lost him
My tester sees a constant tension of -1.7Volt... as if the multivibrator astable is saturated at that value.
Using a dual power supply of ±3volt, there is no change, exept the output of -0.3v, I tried other values of the capacitor as 1microFarad/25Volts a 1microFarad/50Volts, 1microFarad/63Volts, 1microFarad/100Volts and still nothing!!!
I changed the Operational amp. and still nothing.
This is a picture of the board
http://img46.imageshack.us/img46/661/dsc01563b.jpg
Using another board, the same... where the <snip> is the mistake ??!?!?!?
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