Hello AAC,

I'm a student working on a group project and my professor thought it'd be fair to make the groups have "equal brainpower". Basiclaly this means he put all the people who haven't studied the entire semester with the people who actually care about getting an A in the class, myself included.

I've created an electronic oscillator which makes a square wave at the output, and had an LED flash on and off by attaching it to the output and ground.

For the second part, we needed to modify the circuit to have 2 LEDs flashing alternating, so when one is off the other is on. I figured out a way to do this with a transistor, but unfortunately I've just found out that this is not allowed. We need to modify the circuit only by adding wires, or moving LEDs around. My professor told me there is a way to do this by putting the LEDs along one of the feedback loops, either in parallel or some other manner.

The project is due tomorrow and I'm going crazy trying to figure this out. The frustration of having paint sniffers for group partners is abysmal.

 

You can simply put the other diode just like the first one, but pointing in the other direction.

 

Welcome to AAC!
You are turning on the LED when the opamp output goes high. Consider how you could turn on another LED when the output goes low.

 

You can simply put the other diode just like the first one, but pointing in the other direction.

I've tried this, and when I do the 1st LED continues to flash, but the 2nd LED does not light up. I think this is because I am using a 9V battery and it is not a bipolar voltage source.

 

Welcome to AAC!
You are turning on the LED when the opamp output goes high. Consider how you could turn on another LED when the output goes low.

I've tried to have another wire from the 9V source cross a safety 1k resistor, then the LED, then attach to the output, but when I do this both LEDs light up and stay lit! >:'^( Yes those are tears

OH MY GOD IT WORKS NOWW

i lvoe you all!!!! IM NOT GAY

 

Then i guess you added the second LED towards the +supply, which is what needs to be done if you are using single supply.

 

For anyone who stumbles upon this thread and wants to see how I hooked it up, it goes like dis.