Here are circuits made of Resistors, Capacitors and Inductors which are passive components. Crystals, Thermistors, Varistors, Variable Passive RLC are also Passive Parts.
Zeners, Diodes, NPN-PNP Transistors, FET, MOSFET, SCR, Triacs are all discrete active devices.
Circuits using only discrete devices
- 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
More discrete devices circuits below
