Pay close attention to how this switch is connected since it is very common to confuse the terminals and shorting line 220. LM338 regulator must be mounted outside the printed circuit on a suitable heat sink of at least 10 x 10 cm in area. If you want, you can place a DC ammeter in series with the positive terminal of the battery for departure to visually monitor the status of load current. This instrument can be either analog or digital, but is now much more attractive digital. The positive terminal of the instrument connects to the circuit and goes into the battery negative (toward the positive terminal). 0.1 ohm resistor to be mounted on the plate, but raised 2 or 3 cm of this to prevent heat alters the pertinax. You may place a buzzer sound while the LED shines. This must be connected between the anode of the LED and emitter of the transistor and must be of the electronic type, with oscillator included therein.
