Let's build our relay driver circuit. We will do this in three parts, starting with the placements of the components:
Figure 7.11 – Relay driver circuit (part 1 of 3)
Following are the steps for the first part of the build. The step numbers match the numbered black circles in Figure 7.11:
- Place the PC817 into your breadboard, taking care that pin 1 of the IC is connected to the left-hand breadboard bank as illustrated.
- Place a 1kΩ resistor into your breadboard. One end of the resistor connects to pin 1 of the PC817.
- Place the MOSFET into your breadboard, taking care to orientate the component the correct way around regarding the Source, Gate, and Drain legs. Our example layout assumes a 2N7000 MOSFET. Please see Figure 7.8 if you need help to identify the legs.
- Place a 1kΩ resistor into your breadboard. One end of this resistor connects the Gate leg of the MOSFET.
- Place a 100kΩ resistor into your breadboard...