| 摘要 |
<p>A battery-powered DC to DC converter is adjustable in response to the condition of the battery so that an optimum compromise is made between the performance of the battery and the performance of the converter in an application such as charging an electronic strobe flash unit capacitor. The converter includes a transformer (12) having primary (14) and secondary (16) windings, and a switch (18) in series with the primary winding and the battery, for interrupting battery current through the primary winding, to cause current to flow through the secondary winding. A voltage-sensing circuit (30), coupled to the battery, senses the battery open-circuit voltage and the battery load voltage. When the battery load voltage decreases below a predetermined percentage of the battery open-circuit voltage, a control circuit (32) coupled to the voltage-sensing circuit and the switch (18), causes the switch (18) to interrupt current flow in the primary winding (14). The energy drawn from the battery is varied in direct proportion to the battery open-circuit voltage and in inverse proportion to the battery internal resistance so that the load that the converter places on the battery is functionally related to battery condition. </p> |
