Digital tachometer (CB7376E)

Found in Radio Electronics from the 90s, this circuit uses components from that time. However, it can still be elaborated with some ease.

| Clique na imagem para ampliar |

Narrow Range VCO 4046 (CB19078E)
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
Photo Relay with LDR (CB15696E)
In the circuit shown in the figure to the side, the relay is activated when the light stops...
People detector (CB22134E)
With this name, the English publication where we found this circuit indicated a sensitive touch...