Power converter with selectively variable output and controller and display system therefor

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT It will become apparent to those skilled in the art that various modifications to the preferred embodiments of the invention as described herein can be made without departing from the spirit or scope of the invention.
Referring now to the drawings, and to FIG.
1 in particular, circuitry for an external converter output control interface ("TCMS.
TM.
Interface") 14 is shown connected into the circuitry of a preferred type of power switching converter 12 to be used in a recreational vehicle or the like (not shown) for providing DC power to operate various accessories and appliances, and to charge the batteries.
Converter 12 is preferably of the type disclosed in co-pending and commonly owned U.
S.
patent application Ser.
No.
08/255,470 filed Jun.
8, 1994 (now U.
S Pat.
No.
5,600,550), the complete disclosure of which is expressly incorporated herein by reference.
The interface 14 operates to vary the output voltage of the power switching converter in response to a signal from an optional module shown generally in FIG.
2, as discussed further below.
Referring now to FIG.
2, the module 10 includes a module connector 20 which has an input at node (3) connected to the battery voltage and an output at node (1) to deliver the control signal to the converter 12 via the interface 14 shown in FIG.
1.
The input voltage at node (3) is connected to the battery voltage through a first analog circuit 24.
The output, node (1), of the module connector 20 is connected to the microcontroller (U1) 22 of the module 10.
Specifically, the output of the connector 20 is connected to pins 1 and 2 of the microcontroller 22.
When these pins are active, they signal the system to 13.
6 volts ("Normal Mode") and 14.
4 volts ("Boost Mode"), respectively.
Otherwise, system voltage remains at 13.
2 volts ("Trickle Mode").
The microcontroller 22 will output these signals either manually when the user activates the switch 28 or automatically by operation of the software stored in the memory of the microcontroller