Here are circuits made of Resistors, Capacitors and Inductors which are passive components. Crystals, Thermistors, Varistors, Variable Passive RLC are also Passive Parts.Some circuits documented from my design note book are here with the editable schematics.
Circuits using only discrete devices
Zeners, Diodes, NPN-PNP Transistors, FET, MOSFET, SCR, Triacs are all discrete active devices. ICs and Hybrid Modules are made of many discrete and passive components.
In the Integrated Circuits or ASICs, all parts even passives are derived on the Silicon Wafer. In Hybrid Modules the construction uses SMD or Tiny Chip components interconnected in a small ceramic PCB and Hermetically Sealed if needed.
Parts like Switches, Connectors, Relays and PCBs are ElectroMechanical parts. Nuts, Bolts, Screws, Cabinets and enclosures are Mechanical parts.
- Isolated dual power supply from 5V
- Telephone LED status indicator
- Music Sound to light converter
- Simple Water operated relay
- LED Voltage Level Indicator
- Basic Relay or Solenoid Driver
- Mains Voltage Current LED Indicators
- Triac based Lamp Dimmer power control
For a Systems Integrator or Control Panel Designer, the Timers, Controllers, PLC which are Electronic Products become Components or Modules along with Contacters, Current Transformers, AC-DC Drives etc.