"Guessing" a circuit configuration with only the parts list.

Thread Starter

Zander98

Joined Aug 12, 2013
4
Hi There!

So, I've been searching the web for different kinds of circuit configurations to try and ID what the circuit could be just by looking at it. Anyway, a friend of mine is an electronics hobbyist like myself (except that he's way more advanced than I am), so he gave me a list of components, but not a schematic or name of the circuit configuration. He likes to stump me, and suffice it to say, I'm pretty stumped. This is the list:

Op-Amp:
2x LM741

Resistors:
2x 10k
2x 1k
1x 8.2K
1x 5k Pot

Caps:
2x 0.01 uF
2x 1 uF

Diodes:
3x 1N914
1x Red LED
1x Green LED

I've searched a bunch, but I can't figure it out. Any suggestions would be awesome!

Thanks in advance.
-Zander
 

wayneh

Joined Sep 9, 2010
16,102
I'll speculate it's a flip-flop. The op-amp is configured as a square wave generator so that the red and green LEDs flash alternately. Without drawing the circuit, I'm not sure what the 3 1N914 codes would contribute. I could be way off.
 

GopherT

Joined Nov 23, 2012
7,983
I'll speculate it's a flip-flop. The op-amp is configured as a square wave generator so that the red and green LEDs flash alternately. Without drawing the circuit, I'm not sure what the 3 1N914 codes would contribute. I could be way off.

I was guessing a triangle wave generator circuit (one op amp is a square wave generator and one is an integrator). Again, the diodes are a mystery.
 

Thread Starter

Zander98

Joined Aug 12, 2013
4
I'm equally as lost as you guys are. Been searching for a few hours now and I can't seem to find anything for it. It may not even be a circuit with any practical application, so it still eludes me.
 

wayneh

Joined Sep 9, 2010
16,102
I wonder if the diodes are used to alter the timing, as they are in 555 circuits, to give different charge and discharge rates on the timing capacitor.

They could also be used to provide voltage references for a battery tester. One diode is 0.7V, light the red LED. Two diodes is 1.4V, light the green LED.

What is the point of this exercise? Your "friend" is using the world's oldest available op amp. I'm not impressed.
 

business_kid

Joined Feb 5, 2013
22
I wonder if the diodes are used to alter the timing, as they are in 555 circuits, to give different charge and discharge rates on the timing capacitor.

They could also be used to provide voltage references for a battery tester. One diode is 0.7V, light the red LED. Two diodes is 1.4V, light the green LED.

What is the point of this exercise? Your "friend" is using the world's oldest available op amp. I'm not impressed.
Wayneh is right. The 741 is pure crap, the sort of thing for hobbyists to make smoke with. Save your brain for more useful pursuits. Anyone who has info and withholds it is a PITA.
 
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