摘要:
Induction heating apparatus using gate-controlled switching devices includes a zero crossing point detector for detecting the occurrence of each zero crossing point of high frequency energization current, and a timing circuit which provides timing action in response to the detected zero crossing point. The timing action is controlled by a power control circuit which detects the level of energy delivered to a load within a range from the inherent turn-off time of the gate-controlled switching devices to a desired value.
摘要:
Induction heating apparatus using gate-controlled switching devices includes a zero crossing point detector for detecting the occurrence of each zero crossing point of high frequency energization current, and a timing circuit which provides timing action in response to the detected zero crossing point. The timing action is controlled by a power control circuit which detects the level of energy delivered to a load within a range from the inherent turn-off time of the gate-controlled switching devices to a desired value.
摘要:
In an induction heating cooking apparatus, the frequency of electromagnetic energy is varied in response to a desired power setting level within an allowable range and the duty cycle of the energy is varied in response to the setting level while the frequency is set at the lower limit of the allowable range. The combined effects of frequency and duty cycle controls permit the power to vary from as low as 50 watts to as high as 2 kilowatts.
摘要:
An induction heating apparatus of the invention is provided with a pair of inversely parallel connected thyristors which receives power from a low frequency energy source. Depending on the polarity of the source voltage, one of the thyristors is triggered into conduction by a control pulse generated in delayed response to a sensed forward bias potential at its anode for the purpose of supplying a forward current to a commutating circuit which is tuned to a high frequency in the ultrasonic range, whereupon a backward current is generated. The backward current is commutated through the other thyristor to complete a high frequency oscillation. A detector is provided to detect when the magnitude of the backward commutating current reaches a predetermined value for the purpose of terminating the trigger control pulse. The control pulses are supplied simultaneously to both thyristors through a pulse transformer which upon termination of the control pulse generates a counterelectromotive force which negatively biases the thyristor which has been conducting during the first half-cycle of each complete oscillation to reduce its turn-off time.
摘要:
An induction heating apparatus comprises a rectifier (2) for rectifying a voltage from an AC mains supply, a resonance circuit formed by an induction heating coil (4) and a capacitor (4), a semiconductor switching device (6) connected in circuit with the resonance circuit to the output of the rectifier, a diode (7) coupled in anti-parallel relationship with the switching device (6), and a circuit (17; 117, 118) for driving the switching device into conduction at a controlled frequency. Further provided is a transformer (14) which derives a low-frequency energy from the AC mains supply (1). A second coil (9) is electromagnetically coupled with the heating coil (4) for deriving a high-frequency energy. The low- and high-frequency energies are coupled by diodes (10, 11, 15, 16; 132, 133) to the driving circuit to provide power necessary to effect the conduction of the switching device.
摘要:
A frequency inverter using thyristor(s), wherein a gate circuit produces both positive triggering signals and negative reverse-bias signals by utilizing outputs of the timer in order not to fail turnings of the thyristor, and the timing of both signals are automatically controlled to by synchronized with oscillation of the resonance circuit connected to the anode and the cathode of the thyristor, so as to respond to a change of load condition, so that always suitable triggering signals and reverse-bias signals are applied to the gate of the thyristor.
摘要:
A communication system includes a communication apparatus that processes a packet according to control information set by a control apparatus; a first control apparatus that controls the communication apparatus by setting the control information in the communication apparatus; and a second control apparatus that operates in concert with the first control apparatus. The first control apparatus transmits information necessary for interoperation between the first and second control apparatuses to the second control apparatus via the communication apparatus.
摘要:
A method of producing a copper alloy wire rod, containing: a casting step for obtaining an ingot by pouring molten copper of a precipitation strengthening copper alloy into a belt-&-wheel-type or twin-belt-type movable mold; and a rolling step for rolling the ingot obtained by the casting step, which steps are continuously performed, wherein an intermediate material of the copper alloy wire rod in the mid course of the rolling step or immediately after the rolling step is quenched.
摘要:
A gas generator including a cup filled with gas generant molded articles that generate gas by combustion, and an ignitor on which an ignition agent is disposed. Each gas generant molded article is formed of smokeless powders containing nitrocellulose as its major ingredient. Each gas generant molded article includes an explosive containing a fuel agent containing a guanidine derivative and/or a tetrazole derivative and an oxidizing agent containing a metal nitrate and/or perchlorate. Thus, it is possible to provide a gas generator by which the amount of CO gas generated in operation can be reduced and the combustion speed can easily be controlled, and to provide a pretensioner system provided with the gas generator.
摘要:
The present invention aims to give a two package curing type polyurethane coating composition which can form a film having soft, wet and dry feelings simultaneously and which maintains general properties such as designing property, film strength, pot life, resistance to scratching and discoloration, resistance to stains with fats and oils and the like, and to provide a coated article with the coating composition. The two package curing type polyurethane coating composition comprises a resin solution containing an acrylic polyol and a curing agent solution containing a polyisocyanate. The resin solution contains urethane resin beads (A) in the amount of 25 to 50 parts by weight and an organic matting agent (B) in the amount of 3 to 10 parts by weight, and the total of (A) and (B) is at least 30 parts by weight in 100 parts by weight of solid contents of the resin solution. And the equivalent ratio of OH groups/NCO groups of the acrylic polyol and the polyisocyanate is in the range of 4.5:1 to 1.5:1.