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 high voltage source is suitable for valve circuits and other applications. The circuit uses a...
With this circuit it is possible to use a frequency meter as a tachometer. The circuit was found in...
This preamp is from a documentation from the 60s. Of course, transistors are rare today, but the...