This circuit was found in a Texas Instruments documentation from the 1980s. The circuit monitors engine temperature by warning of engine warm-up and warning when the fan is on.
This circuit was found in the May 1989 issue of Radio Electronics magazine. The circuit requires a...
We find this microphone voice effect in 1992 documentation. The vibration of the relay contacts...
This circuit to increase the sensitivity of instruments to 100 uA (or close to it) was found in...