摘要:
A plurality of magnetic field sensors are mounted adjacent the periphery of an induction heating coil of flat, spiral configuration which is energized by ultrasonic frequency energy to generate a time-varying magnetic field. The magnetic field sensors are connected in a ciruit to produce an output signal when a magnetic utensil load is placed asymmetrically with respect to the center of the induction heating coil. In response to sensor output exceeding a predetermined value a warning indication is provided. The ultrasonic energy level is reduced in response to the warning indication to minimize radio interference which would otherwise occur due to leakage magnetic flux.
摘要:
Electromagnetic coupling between a pan or utensil load to be heated by magnetic induction and a source of high frequency magnetic flux is sensed by detecting a current which is indicative of the electromagnetic coupling by means of a current transformer. The detected current is compared with a reference level. Intermittent generation of the magnetic flux is commenced when, for example, a small magnetic metal object is inadvertently placed as a load with the result that the detected current becomes lower than the reference level. This allows intermittent check for the presence and absence of the inadvertently placed load for subsequent cooking operations and minimization of the heat generated therein.
摘要:
An induction heating apparatus includes a saturable reactor having a pair of rectangular ferrite cores. An air gap is provided in each ferrite core to provide a gradually increasing saturation characteristic on the magnetization curve of the cores. A pair of series-connected load windings is coiled around each core and a control winding is coiled around a common magnetic path of the cores. A power control circuit produces a DC control current that passes through the control winding. The high frequency energization current is passed through the load windings. Means are provided to control the DC control current at a desired setting. Preferably, the actual power level is detected to control the DC current through a feedback loop.
摘要:
An induction heating apparatus is provided with protective circuit arrangements which ensure against surge currents caused by inappropriately timed gating-on of a gate controlled rectifier or by erroneous use of a load material such as non-magnetic or ferro-magnetic material. The timed gating of the gate-controlled rectifier is accomplished by means of a delay circuit which serves to count timing after a rectified excitation potential drops to the zero voltage point. A coincidence circuit is provided to detect coincidence of two signals, one is a pulse having a predetermined width and the other is a signal derived when the periodic cycle of the energization currents departs from the predetermined cycle period.
摘要:
An induction cooking apparatus having a plurality of induction heating coils disposed in an array for induction-heating a metallic heating load by electromagnetic induction. Air inlet ports are formed at the front end of the appliance to admit cooling air for cooling the interior of the cooking appliance and air outlet ports are formed at the rear end of the appliance. The apparatus ensures comfortable cooking without exposing the user to hot exhaust air and, also, better cooling without drawing in hot exhaust air or hot steam from the food materials. Furthermore, a partition is provided within the appliance for separating the power converter unit from the operating unit for blocking objectionable movement of cooling air and blocking induction radiation from the power converter unit so as to protect the operating unit from the induction radiation from the power converter unit and prevent faulty operation thereof, and a cooling fan is disposed in an orifice in the partition for circulating cooling air within the appliance and ensuring an efficient cooling performance.
摘要:
An induction heating apparatus is provided with protective circuit arrangements which ensure against surge currents caused by inappropriately timed gating-on of a gate controlled rectifier or by erroneous use of a load material such as non-magnetic or ferromagnetic material. The timed gating of the gate-controlled rectifier is accomplished by means of a delay circuit which serves to count timing after a rectified excitation potential drops to the zero voltage point. A coincidence circuit is provided to detect coincidence of two signals, one is a pulse having a predetermined width and the other is a signal derived when the periodic cycle of the energization currents departs from the predetermined cycle period.
摘要:
An induction heating apparatus including a thyristor adapted to receive power from a power source, a gating control circuit for generating gating pulses for application to the gating control terminal of the thyristor, a commutating circuit which commutates off the thyristor, and a differentiator connected across the anode and cathode terminals of the thyristor to detect the power consumption of an inductively heated cooking ware. The gating control circuit comprises a gating pulse generator and a smoothing circuit for filtering the signal from the differentiator into a d-c signal which is compared with a reference level to detect the deviation of the power consumption from the reference value. The gating pulse generator is responsive to a potential at the anode of the thyristor to initiate timing action to determine the interpulse period or turn-off time of the thyristor and also responsive to the deviation of power consumption to vary the interpulse period.
摘要:
A tensioner has a cylindrical member having multiple locking teeth, one or multiple locking pieces having locking teeth to be engaged with the locking teeth, and a locking piece receiving part to receive the aforementioned locking pieces. A shaft member is disposed inside the cylindrical member, and either the cylindrical member or the shaft member constitutes a thrust member that can be driven forward and backward by a biasing force. A ratchet mechanism allows the thrust member to move forward by the locking pieces riding over the locking teeth of the cylindrical member as they move in a reduced-diameter direction and constrains retraction of the thrust member by the locking pieces engaging with the locking teeth of the cylindrical member as they move in an increased-diameter direction. The locking teeth are all thread-like teeth having a lead angle.
摘要:
A fuel supplying apparatus is disclosed that suppresses intrusion of oil mist into a negative pressure introducing inlet of an automatic cock and that, thereby, improves the degree of freedom of disposition. The negative pressure introducing inlet of the automatic cock is connected to a crankcase through a negative pressure communication path. The automatic cock is opened by a negative pressure generated in the crankcase and, thereby, a fuel supply path is opened that is for supplying fuel from a fuel tank to an internal combustion engine. The negative pressure communication path communicates with the air cleaner through a purge path that branches from the negative pressure communication path at a halfway point of the negative pressure communication path. The point at which the purge path branches from the negative pressure communication path is set to be at the lowest position of the negative pressure communication path to be able to collect the oil mist intruding from the crankcase.
摘要:
An ink jet type printing apparatus in which an ink supply needle is located near one side in a direction perpendicular to the reciprocated directions of a carriage, a circuit board is mounted on a wall of an ink cartridge in the vicinity of the side on which an ink supply port is formed and plural contacts for connecting to external control means are formed on the exposed surface of the circuit board.