Bike speedometer (CB20497E)

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

CMOS Output Zero Crossing Detector (CB14158E)
We found this circuit in the Linear Applications Handbook published by National Semiconductor in...
555 Fixed Period Generator (CB25498E)
In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed...
LM3914 Peak Meter (CB24635E)
In the figure we have a simple way to have a peak bargraph indicator. The amplifier is of the...