This circuit for a 16-channel infrared transmitter was found in the August 1984 issue of Radio Electronics magazine. The circuit is powered by a 9 V battery.
This circuit is from a 1991 publication. It divides the frequency of a TTL signal applied to its...
We found this heart rate sensor circuit in a Popular Electronics from the 90s. The placement of...
We found this circuit in a documentation from the 90's. Information on the A/D converter was not...