Using an analog microamperimeter this circuit has a phototransistor adapted to the wheel as a sensor. The circuit is from American documentation from the 1980s, but the components are common today.
This circuit is from a documentation on the MC1539 from Motorola and may, however, be implemented...
This circuit makes na incandescent lamp flash fast producing the stroboscopic effect. The speed is...
This interesting circuit found in an Elektor from the 90s controls loads in four quadrants of the driving...