This circuit originally came out in a Budget Electronics from 1981. The American magazine no longer exists, but we can use BC548 for Q1 and BC558 for Q2 and the circuit can be assembled today. R6 is an LDR, the circuit is adjusted to indicate the light levels on two LEDs. R1 has 10k to 220k depending on the light level of the adjusted range.
| Clique na imagem para ampliar |
