In the previous chapter, we looked at core electronic circuits and concepts that you will use when interfacing digital and analog circuits with your Raspberry Pi's GPIO pins.
In this chapter, we will cover how to switch things on and off that require more voltage and current than can be safely used with your Raspberry Pi. When it comes to electronics, hundreds of different components can be used for controlling and switching. And there are thousands of different ways they can be configured. We will be focusing on three common complements—optocouplers, transistors, and relays.
An understanding of how to control and switch electrical circuits on or off is a very important topic when interfacing with a Raspberry Pi. As we discussed in Chapter 5, Connecting your Raspberry Pi to the Physical World, Raspberry Pi GPIO pins...
