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c. Voltage Regulator, 78L05 (U4): This component takes the 9 volts from the power jack
and converts it to 5 volts to run the microcontroller. This component is shaped like a three-
quarter moon and looks very similar to the transistors you installed earlier. Install the voltage
regulator on the board in the correct orientation (it is polarized), bend the leads out on the
other side of the board. Solder and clip the leads (88,89).
88
89
11. DIP Switches (S5, S6): “DIP” stands for “Dual In-line Package,” which describes the pin layout on
these miniature switches. When installing them, make sure the labels on the switches line up with
the markings on the PCB (90). Hold the switch in place with your finger. Flip the board over and
tack one pin in place. Now set down the board or place it in your clamp and solder the rest of
the pins properly (91).
90
91
12. Relay (RL1): Relays are just electrically controlled switches. This allows us to have a true-bypass
signal path that is digitally controlled. There is only one way the relay fits in its footprint. Install it
the same way as the DIP switches, holding it from the top (92) while tacking down one pin (93).
Finish soldering the rest of the pins.
92
93
