A switching regulated power supply, the output voltage of which is regulated according to a pulse width modulation method, is provided with a reference oscillator for generating first and second synchronizing signals, phases of which are complement each other, first and second time constant circuits, to which the first and second synchronizing signals are supplied respectively, each one of the circuits having a resister and a capacity device including a variable capacity diode, charge speed up diodes coupled in parallel with the resisters, first and second CMOS drive circuits for inputting the output signals of the first and second time constant circuits and for providing drive signals according to the output signals, a DC-DC converter having push-pull switching devices driven by the drive signals of said first and second CMOS drive circuits, and a control circuit for detecting an output voltage of the DC-DC converter and for controlling capacitance of the variable capacity diodes of said first and second time constant circuits in response to the output voltage of said DC-DC conveter.
A power converter apparatus employing a capacitively coupled feedback network for facilitating bi-directional communication between a primary and secondary side of the converter while maintaining direct current isolation.
A push-pull or forward switching power supply is operable over a voltage range of 4.5 to 40 volts at high efficiency. At low voltages a primary winding or pair of windings are activated by a PWM control to regulate the output current. At high voltages, an additional primary winding in series with each of the other winding or windings is also activated by a PWM control.
A flash charging circuit has first and second transistors (TR1, TR2) which are connected to opposite terminals of a primary coil of a transformer, a battery is connected to a center tap provided in a middle portion of the primary coil, and first and second drive pulse signals (S1, S2) are applied to the first and second transistors to drive them alternately with each other, to induce an alternating secondary current in a secondary coil of the transformer. Each of the first and second drive pulse signals have a shorter pulse duration (Pd) than a pulse separation (Ps). The phases of the first and second drive pulse signals are determined such that both the first and second drive pulse signals take a low level for a time (Ta) before and after each drive pulse of the first and second drive pulse signals, so that both the first and second transistors are OFF immediately before either of them is turned ON.
A power supply for a quadrupole mass spectrometer which operates using an RF signal. The RF signal is controllable via a feedback loop. The feedback loop is from the output, through a comparator, and compared to a digital signal. An air core transformer is used to minimize the weight. The air core transformer is driven via two out of phase sawtooth signals which drive opposite ends of the transformer.
A personal computer includes a DC to DC converter which employs a dual function capacitive energy storage device at the output rail of the converter. The energy storage device provides both a transition control function and a bulk or output function. In this manner, the size and expense of a separate bulk capacitor is advantageously avoided. The converter includes a switching transistor coupled to a bulk inductor. The switching transistor exhibits a high frequency switching rate which is sufficiently high to permit the inductor to directly replenish the capacitive energy storage device thus enabling the converter to withstand both major and minor load fluctuations without loss of voltage regulation at the output rail.
