Introduction: Op Amps Without Circuit Boards

By Lafe
About: I'm an applied physicist by training(phd Yale 2006, BA Berkeley 1998, math and physics), and have done physics research in the federal government and product development in the private sector, starting two of …

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.

Step 1: Cut Off Unwanted Leads

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

Step 2: Add Feedback Resistor

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.

Step 3: Add Input Resistor and Other Bias Resistors

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.