Found in a 1966 General Electric manual, this circuit provides a delay in starting. The motor is of the universal type and the triac according to its current.
Here is a simple source without a transformer for currents up to 50 mA. The voltage depends on the...
We found this circuit in an old QST magazine. The circuit is powered according to the thermostatic relay...
This simple field strength meter is from a transistor book from the 60's. The transistor is made...