Published in a PE Hobbyst Handbook of 1991, this sensor uses an integrated circuit that is unusual today. The circuit is based on a high frequency oscillator.
This circuit can provide a maximum load current of 1 A. The integrated circuit must have a...
This control for 12 V drills was found in a 90s Elektor. The components are current, and Q1 can be...
Figure 1 shows how the 4029 can be connected to count up to 10 and also up to 18. If pin 9 is...