General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs that are not common components today. Note the timing components that may change.
August 2016 - It can be obtained from Mouser Electronics the new DC-DC PFM Step-Down XC9272 from...
This circuit is the equivalent of the CB121, but is triggered with the negative transition of the...
This control, from a 1982 documentation, uses an integrated circuit and a Darlington transistor, as shown...