A 6V lead-acid battery charger. Note the LM317 regulator and power resistor at the top. Also present is a 5V voltage regulator for the actual device being used here.
When you want to see the stars, find someplace dark
A 6V lead-acid battery charger. Note the LM317 regulator and power resistor at the top. Also present is a 5V voltage regulator for the actual device being used here.