Precision Tone Switch 4046 (CB25256E)

Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The circuit is from a Radio Electronics from December 1989.

| Clique na imagem para ampliar |

Reset Pulse Generator (CB6615E)
This circuit is from Dutch documentation from 1967. The circuit works with a component of the...
Logic Probe 7811 (CB19217E)
The integrated circuit used in this application is not very common. The circuit is intended for...
LM3900 Voltage Regulator (CB4031E)
The output voltage depends on the zener and the current determines the type of transistor used....