This 130 V drive uses an integrated circuit not very easy to find, which is the LM143. The circuit is suggested by National Semiconductor in its 1994 Linear Applications Handbook.
To obtain variable frequency signals, the circuit in the figure is recommended. In this circuit, the...
This circuit was found in old English documentation. It can be improved by using resistors of...
This circuit was published in a 1979 magazine, but it can still be easily assembled as the...