Abstract: A voltage conversion circuit includes a transformer having a primary winding and a secondary winding with an output terminal. The primary winding is coupled in series with a switching circuit across a source of DC potential. The switching circuit periodically interrupts the DC potential to the primary winding and upon the interruption the primary winding undesirably produces a switching circuit damaging voltage spike. A voltage suppression circuit is responsive to the voltage polarity reversal in the transformer primary, which occurs when the input voltage is interrupted thereto for transferring the energy, which would otherwise produce the voltage spike, to the converter output terminal to add energy thereto. When the switching circuit is non-operational no voltage reversals are present in the transformer and no voltage is therefore passed to the output terminal.

Abstract: A voltage converter of the transformer type which incorporates at least one switching transistor coupled to control the application of current to the transformer primary and circuitry for switching the transistor on and off to control the current through the primary winding. When the output of the converter is shorted, the switching rate undesirably increases causing potential damage to the converter. A frequency detecting circuit detects the increase in switching frequency and acts to reduce the input voltage to the converter to prevent damage thereto.

Abstract: An airborne weather radar system displays on a display screen a weather map in the form of a matrix of spots of intensity with N possible intensity levels ranging from a lowest level to a highest level where N>2 and where the intensity levels correspond to respective data signals provided by the radar system. The intensity control on the weather radar system is operator controllable to cause data signals corresponding to all intensity levels except the lowest to be converted to signals corresponding to the highest level. Therefore, only the highest and lowest intensity levels are displayed.

Abstract: A power supply which incorporates a feedback network for maintaining an output parameter at a nominal value, includes apparatus, which, upon a change in an environmental parameter provides a signal to the feedback network to alter substantially the output parameter from its nominal value. Such a power supply is useful in a cathode ray tube type display system subject to damaging voltage breakdowns at high altitudes.