Op-Amp Trainer Kit

Students meet op-amps as equations — inverting gain, virtual ground, the integrator formula — but many never see the configurations actually work on a bench, because wiring each one from scratch on a breadboard is fiddly and error-prone. A trainer kit fixes that: one well-built board, one rotary switch, and every classic configuration is a click away. This project builds such a kit around a socketed TL072 dual op-amp: the mode selector routes the input network for inverting, non-inverting, summing, difference, comparator and integrator modes, while potentiometers adjust gain, offset and input level. An onboard ±12 V supply from 7812/7912 regulators with power LEDs removes the bench-supply hassle, and labeled test points plus banana-jack I/O make probing with a scope straightforward. Each mode ships with an experiment procedure, so the report contains the student's own measured gains and waveforms.

1. The student powers the kit from a single DC input; the 7812/7912 regulators produce ±12 V, shown by the power LEDs.
2. The mode-select switch routes the input and feedback networks to form the chosen topology — e.g. inverting amplifier with the selected feedback resistor.
3. A signal (from a function generator or the kit's own test source) is applied to the input jacks.
4. The student adjusts the gain and offset potentiometers and probes the output at the test points with a multimeter or oscilloscope.
5. Each experiment procedure records input vs output, and the student compares the measured gain or waveform with the theoretical value.
6. Swapping the socketed op-amp lets the student repeat a key experiment and discuss device differences in the viva.

Tech stack:

• TL072 dual op-amp (socketed)
• 7812 / 7912 dual supply regulators
• Rotary mode-select switch
• Potentiometer gain/offset controls
• Banana-jack I/O and test points
• Trainer PCB assembly
• Oscilloscope / multimeter (experiments)

• [Six selectable op-amp modes] A rotary mode switch configures inverting, non-inverting, summing, difference, comparator and integrator topologies — the complete classic set on one board.
• [Socketed TL072] The dual op-amp sits in a socket (LM741-compatible footprint), so the student can swap devices and compare behavior — and a dead IC never kills the board.
• [Gain and offset controls] Front-panel potentiometers adjust feedback gain and input offset, making the gain equation something the student turns and measures, not just reads.
• [Onboard ±12 V supply] 7812/7912 regulators with power LEDs generate the dual supply from a single DC input — no bench supply needed for the experiments.
• [Test points and banana I/O] Labeled test points at input, output and supply rails, plus IN+/IN−/OUT banana jacks, make scope probing and signal injection clean.
• [Per-mode experiment procedures] Each configuration ships with a step-by-step experiment: what to apply, what to measure, and the expected relationship — the report writes itself from the student's readings.
• [Comparator with hysteresis option] The comparator mode includes a documented hysteresis variant, so the student sees chatter-free switching and understands positive feedback.

• Working op-amp trainer kit PCB with enclosure-ready layout
• Socketed TL072 (plus LM741 for comparison)
• Experiment manual with per-mode procedures and expected results
• Schematic and PCB documentation
• Project report PDF (op-amp theory, topologies, student measurements)
• PPT presentation for final review
• Viva Q&A preparation document

• General-purpose audio/DC op-amps only in the socket — high-speed or high-voltage parts are out of scope.
• Bandwidth is bounded by the TL072's gain-bandwidth product; the integrator and high-gain modes are documented with their frequency limits.
• It is a teaching instrument, not a precision lab standard — offsets and tolerances are part of the experiments, not hidden.
• Requires an external signal source and scope/multimeter for the experiments (standard lab equipment).
• Single op-amp channel under test at a time; dual-channel experiments need external wiring.