This circuit was found in Analog Devices documentation from the 90's. The integrated circuit used is from the time. The circuit is for HDTV signals. of the time.
This is a combined circuit of tone generator and preamplifier. We found it in a 1975...
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
We found this circuit in the Linear Applications Handbook by National Semiconductor. The base is...