This circuit is from the 1983 Intersil Databook. The circuit has an A / D converter for display of 4 and a half digits being powered by a voltage of 9 V.
This encoded lock circuit with alarm for use in homes was found in a publication from the 90s. The...
The circuit shown was found in the 1994 National Semiconductor Linear Applications Handbook. The...
This circuit is from a 1979 documentation. The FET can be the BF245 or MPF102 and the bipolar...