This automatic street light controller helps to reduce energy consumption during daylight hours. Components We will need the main components: BC547 transistor – 2 pcs. 1N4007 – 1 pc. LDR (light dependent resistor) – 1 pc. Relay – 1 pc. 1K resistor – 1 pc. The whole list looks like this: BC547 -2 transistor LDR …