Bike speedometer (CB20497E)

This circuit can be powered by a solar cell. The circuit is from a 1991 documentation having a phototransistor as sensor.

Notch filter LM3900 (CB15259E)
Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found...
Circuit with sensor (CB7104E)
This type of sensor was used in sensitive infrared systems from the 1960s. This circuit was found...
Variable Voltage Controlled Attenuator (CB4236E)
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...