To make sure a diode is correctly connected, follow these main steps:
- Identify the diode terminals: The anode is the positive side (usually without a stripe), and the cathode is the negative side (usually marked with a stripe or band).
- Check the circuit orientation: Connect the anode to the positive voltage side and the cathode to the negative or ground side to ensure the diode is forward-biased.
- Use a multimeter in diode test mode: Connect the multimeter's positive lead to the anode and negative lead to the cathode. A good diode will show a forward voltage drop (typically 0.6–0.7V for silicon diodes). Reverse the leads, and the reading should show no conduction (very high resistance). If the opposite happens, the diode may be damaged or reversed.
- Visual inspection: Ensure no physical damage or burn marks on the diode and confirm proper soldering or connection.
- Test the circuit behavior if applicable: Power the circuit and observe that current flows only in the forward direction and is blocked in reverse.
This method confirms both the diode's correct polarity and functional status in the circuit to ensure proper connection and operation.
