Figure 3.16. The lower prong of a two wire line plug goes to the bottom end of a transformer primary. The upper prong goes through a fuse, then through a switch to the upper end of the primary. There is a lamp in parallel with the primary. The transformer secondary has its center-tap connected to circuit common. The upper end of the secondary goes to the anode of a diode. The lower end of the secondary goes to the anode of another diode. The two cathodes are connected together and go to the positive end of a 2200 microfarad capacitor. The other end of the cap goes to common. The positive end of the cap goes to the input terminal of a 5 volt regulator labeled LM7805. There is a 0.1 microfarad cap connected between the input terminal and the common terminal of the regulator. The common terminal of the regulator goes to circuit common. There is another 0.1 microfarad cap connected between the output terminal and common terminal of the regulator. The output terminal of the regulator goes to the positive end of a 100 microfarad cap. The negative end goes to common. The output of the regulator goes to the positive output terminal of the power supply. The negative output of the power supply goes to the circuit common. End verbal description.
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