Mini drill control (CB8767E)

This control for 12 V drills was found in a 90s Elektor. The components are current, and Q1 can be replaced by a TIP42 mounted on a heat radiator.

| Clique na imagem para ampliar |

Electronic Bingo (CB17441E)
This 2001 CMOS digital circuit draws numbers from 00 to 99 and can be expanded. However, it does...
3 kHz Low Pass Filter LM3900 (CB13837E)
This filter was found in an old publication from 1977. The circuit must use a simple two-voltage source...
Freezer Alarm (CB1281E)
This circuit beeps when the sensor is triggered by the opening of the freezer door or other...