This circuit found in a 1964 US publication reverses the signal level by providing 9 to 0 V outputs from 0 to 9 V signals. Transistors may be equivalent.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit activates a relay by activating one of a series of optical sensors that can be...
We found this circuit in a 1996 publication. Equivalent components can be tried, especially in the...