Speed game for 3 competitors (CB20958E)

We found this circuit in a Popular Electronics from the 80s. It is a game of reaction speed for 3 competitors. Indicator LEDs are used.

| Clique na imagem para ampliar |

Two Transistors Interface or Shield (CB13109E)
The configuration shown in the figure uses two NPN transistors activating the load when the input...
5 V zener diode with Transistors (CB20459E)
In the absence of a 5 V zener diode, we can create an equivalent configuration with two...
6 V power supply with power zener (CB21531E)
This circuit provides 6.3V of output from a 9V input. The circuit was found in a Dutch publication from...