Buck-boost regulated D.C. to D.C. power supply

A power supply, having an input node and an output node, for supplying DC electrical power to an electronic control system of an engine, which comprises:

• a series switching regulator section for regulating the voltage at the output node having a transformer with primary and secondary windings, switching means for switching on and off the flow of current from the input node through the primary winding to the output node, and switching control circuit means for controlling the operation of the switching means in response to the voltage at the output node;
• a shunt switching regulator section for boosting the voltage supplied at the input node to produce a desired voltage at the output node when the voltage at the input node is below a predetermined value, the shunt switching regulator section having shunt means for intermittently shunting current through the primary winding towards ground and oscillator circuit means for controlling the operation of the shunt means;
• a free-wheeling diode, and wherein
• the free-wheeling diode and the secondary winding are connected in series combination between the output node and ground for allowing current to flow through the secondary winding into the output node;
• whereby excess energy stored in the transformer on account of current flowing through the primary winding may be beneficially transferred via magnetic coupling and the secondary winding to the output node.

A regulated power supply, having an input node, an output node and a ground, for supplying DC electrical power to an electronic control system in an automotive engine, which comprises:

• a series switching regulator section for regulating the voltage at the output node having (a) a transformer provided with a primary winding and a secondary winding, each winding having two leads, the first lead of the primary winding connected to the input node, (b) a free-wheeling diode connected in series with the secondary winding, the series combination of the free-wheeling diode and the secondary winding connected between the output node and ground, (c) a filter capacitor connected between the output node and ground for smoothing the voltage at the output node, (d) a solid-state switching device, connected between the second lead of the primary winding and the output node and provided with a control gate, for switching on and off the flow of current from the primary winding to the output node, and (e) a switching control circuit means, connected to the control gate of the switching device and to the output node, for controlling the operation of the switching device in response to the voltage at the output node;
• and
• a shunt switching regulator section for boosting the voltage supplied at the input node to produce the desired voltage at the output node when the voltage at the input node is below a predetermined value, having (a) a solid-state shunt device, connected between the second lead of the primary winding and ground and provided with a control gate, for intermittently shunting current from the primary winding to ground in order to store magnetic energy in the transformer for disbursement of the stored energy through the secondary winding to the output node when the shunt device is turned off, and (b) an oscillator connected to the input and output nodes and provided with an output connected to the control gate of the shunt device and to the switching control circuit means, for controlling the operation of the shunt device in response to voltages at the input and output nodes, and for signaling the switching control circuit means to turn off the switching device when the shunt device is turned on.