Standby boost converter

A circuit connected to a DC power source comprising:

• energy storage means;
• a boost converter having a first rectifier connected in series with said energy storage means, said rectifier and energy storage means connected in parallel with said DC power source, an inductor in series with a controllable switch,
• said inductor and controllable switch in parallel with said energy storage means, a second rectifier connected to the junction of said inductor an said controllable switch, an output filter capacitor connected at one end to said second rectifier and at the other end to one side of the DC power source, said first and second rectifiers poled to transfer power from said DC power source to said energy storage means and from said inductor to said capacitor, respectively, and control means for modulating said controllable switch;
• and
• a second power converter having its input coupled to the output of said boost converter and connected through a third rectifier to the DC power source, said control means responsive to the input voltage of the second power converter for modulating said controllable switch when the input voltage of the boost converter is below a predetermined value, so that said second power converter receives power at a predetermined minimum voltage.