Op Amps Without Circuit Boards

by lafelabs in Circuits > Electronics

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Op Amps Without Circuit Boards

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16, 8:00 PM.jpg

This is another example of fabricating circuits without circuit boards or breadboards, using direct solder and wires and tweezers in 3 dimensions. I'm using the MCP6241 op amp here, and making one amp of voltage gain 10,000 and one of voltage gain 100. I use a combination of surface mount and axial resistors, and I don't specify which one you use when. Also, the instructions here are assuming you already know and care about op amps, I'll have another more basic one for beginners later. I show schematics I'm going off of directly as I go. Again, I advocate in most cases, keeping that schematic with the physical thing for future users to be able to understand. That schematic should also contain a URL back to your or my or someone else's documentation.

Cut Off Unwanted Leads

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16, 8:00 PM.jpg
16, 8:00 PM.jpg

pins 1,5 and 8. Cut them off with clippers! Smash!

Add Feedback Resistor

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16, 8:00 PM.jpg

I use a 1 M Ohm 0603 SMT resistor for this every time because I bought a ton of those a long time ago and have an effectively infinite number and that gives me a ton of choice for gain based on the input resistor.

Add Input Resistor and Other Bias Resistors

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As shown. That's it. If you're making a simple circuit with a simple op amp, you should never need either a breadboard or PCB. Just grab, solder and go.