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ENPL

Building Analog Computers

Design circuits that compute using continuous electrical signals—addition, integration, differentiation, and more

intellectualphysicalcrafty$$ mediuma weekenddifficulty 4/5

Create computers that work without digital logic: use op-amps to build analog circuits that solve equations electrically. Build adders, integrators, differentiators, logarithmic circuits, and analog computers that solve differential equations in real-time. This hobby teaches you analog circuit design, transfer functions, and mathematical thinking at the hardware level. It's retro-computing in the truest sense.

How to start

  1. 1
    Study operational amplifier (op-amp) fundamentals
  2. 2
    Build simple summing amplifier circuit
  3. 3
    Progress to integrator and differentiator circuits
  4. 4
    Design a function generator (sine, triangle, sawtooth)
  5. 5
    Build a simple analog computer solving basic differential equations
  6. 6
    Use oscilloscope to visualize computation in real-time

What you'll need

  • Operational Amplifier ICs
    Essential
    ~$5
  • Precision Resistors & Capacitors
    Essential
    ~$20
  • Breadboard & Jumpers
    Essential
    ~$10
  • Dual Power Supply (±12V or similar)
    Essential
    ~$30
  • Oscilloscope (essential for testing)
    Essential
    ~$150
  • Function Generator
    Nice to have
    ~$80

Where to learn more

Plot twists

Ways to spice this up when the basics get boring.

  • Build a mechanical analog computer variant
  • Design a hybrid analog-digital system
  • Create a precision measurement system using analog circuits
  • Build an analog synthesizer from scratch
  • Design custom filters for signal processing
ADHD notes

Immediate oscilloscope feedback is hyperfocusing gold. Each circuit is a small project with quick results. Math becomes tangible and visual.

Fun fact

Before digital computers dominated, analog computers solved complex engineering problems—WWII artillery ballistics were computed with analog circuits, not numbers.

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