Abstract: A power supply for vibrating compressors having an inverter for converting direct current (d-c) into alternating current (a-c). The power supply includes a d-c power source section for applying d-c voltage to the inverter, a current detecting apparatures for detecting a current flowing in the vibrating compressor, a control section having a frequency following circuit for generating a frequency following the resonance frequency of the vibrating compressor on the basis of a current detected by the current detecting apparatures, and an inverter control circuit for controlling the inverter with the frequency generated by the frequency following circuit. The vibrating compressor is driven by an a-c voltage of the frequency agreeing with the resonance frequency of the vibrating compressor.

Abstract: A power supply for vibrating compressors comprises a voltage booster circuit portion having voltage changing means for boosting the DC voltage of a commercially available battery and changing the boosted voltage, and an AC voltage generating circuit portion for supplying the boosted DC voltage to the vibrating compressor. The AC voltage generating circuit portion comprises a MOSFET or bipolar transistor for driving a vibrating compressor, a timer IC for generating pulses to cause the MOSFET or bipolar transistor to switch, a forced operation circuit for detecting a timing at which a counter electromotive force generated by the vibrating compressor during the OFF period of the MOSFET or bipolar transistor is recovered to the neighborhood of 0 volts and forcibly reversing the output of the timer IC, and a driver for driving the MOSFET based on the output of the timer IC or a base-current supply circuit for controlling the bipolar transistor.

Abstract: An engine-driven power generating system having a bridge circuit section in which low-frequency switching elements are driven alternately by low-frequency drive signals, and high-frequency switching elements driven by high-frequency drive signals during the ON period of the low-frequency switching elements are connected in a bridge network, and an inverter circuit section having a drive signal supply circuit for supplying low-frequency and high-frequency drive signals are each supplied to the low-frequency and high-frequency switching elements that form a pair; the a-c voltage generated by an engine-driven a-c generator is converted into d-c voltage that is in turn converted into a predetermined level of low-frequency a-c voltage; characterized in that an overcurrent detecting circuit for detecting an overcurrent flowing in the bridge circuit section at a level higher than a predetermined level, a drive-signal control circuit that outputs to a drive-signal supply circuit, when the overcurrent detecting circui

Abstract: The present invention describes a system for controlling the planing angle of a boat powered by an outboard motor. Sensors are provided which measures the inclination of the propeller of the boat and the acceleration of the boat. An angle-changing motor is mounted between the outboard motor and the boat and a motor control means receives signals from the angle sensor and the acceleration sensor in order to control the angle between the propeller and the boat. Other sensors can be applied to detect the angle between the outboard motor and the boat in order to prevent excessive angles from occurring. A timer can also be used to nullify the effects of the acceleration sensor after a predetermined time.