This circuit is from old documentation, but it can be implemented with more modern equivalent components. The transistor can be the TIP31 with a heatsink and the 1N4002 diodes.
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
Found in a 90s Electronics Engineering, this circuit makes use of components of the time. The...
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...