Hardware Reference
In-Depth Information
Figure 10-12.
Relay placement on the breadboard
2.
Install the diode across the terminals of the relay coil. This diode is used to prevent a
potential voltage spike from the relay coil traveling back down into the Raspberry Pi.
Remember that when you install a diode it is polarity-sensitive. The side with the stripe
around it will be the cathode. Install a diode next to the coil and across the two halves of
the breadboard in the exact same manner that you did for the relays.
3.
Install jumper wire between each side of the relay's coil and the diode.
4.
Install a jumper wire between the ground and one side of each of the relay coils.
The ground side of the relay coil must be the same side that the anode of the diode is
connected to. Take a look at Figure
10-13
to see my jumpers and diodes installed.
