The integrated circuits used in this configuration are not common today. The circuit is from the 1983 Intersil Databook. The indicator is 8 digits.
This circuit, suggested by National Semiconductor, decodes audio signals from stereo TV...
Found in a 1970 documentation, this circuit makes use of 741 operational amplifiers that are...
Suggested by General Electric in 1967 documentation this circuit uses an isolation transformer to...