72 results about "Lenz's law" patented technology

The invention describes a multiple lamp balance transformer and a drive circuit. The multiple lamp balance transformer has two magnetic cores with a closed magnetic flux path and two coils wound around the closed magnetic flux path. The two coils have the same number of windings. The impedance property of the coil and Lenz's Law are used to balance the operating current of the lamps connected to the coils. The drive circuit has a multiple lamp balance transformer connected to several lamps, and a boost transformer uses a controller to supply the current and voltage to the lamps. A current detect / protect circuit connected to the coils and the controller detects the current passing through the coils and converts the operating current of the lamp into a voltage to be sent to the controller, so that the controller controls and provides sufficient power to the lamps.

What is disclosed are embodiments of magnetic torque transfer devices utilizing torque transfer by magnetic induction in which an induction cylinder fabricated from an electrical conductor is interposed into the gap between a pair of magnetically coupled primary and secondary rotors. Rotation of the induction cylinder relative to the coupled rotors evokes magnetic torque transfer in accordance with Lenz's Law. The primary rotor rotates within a toroid shaped stator. The stator may be configured for rolling biphasic coil control. The secondary rotor is attached to a propeller. The device may function as a turbine when fluid is directed to flow over the propeller. The device may function as a pump when AC power is supplied to the stator. Rolling biphasic motor control includes dividing motor coils into increments, then configuring groups of contiguous increments into virtual coils, which revolve in tandem with the primary rotor so to achieve continuous and optimal torque transfer with minimum torque ripple.

The present invention belongs to the technical field of physics teaching demonstration experiment devices, and especially relates to an experiment device for demonstration of electromagnetism induction phenomenon in physics teaching. The device comprises a demonstration rack and an electromagnetic induction mechanism arranged on the demonstration rack; the electromagnetic induction mechanism comprises permanent magnets, demonstration channels arranged below the permanent magnets, induction coils winded at the outer surfaces of the demonstration channels and an indication bulb. One ends of thepermanent magnets are movably connected with the demonstration rack, two ends of the induction coils are provided with binding posts, and the indication bulb is connected with the binding posts through wires. Through comparison experiment, the electromagnetic induction demonstration experiment device for physics teaching allows students to clearly understand the Lenz's law, the right hand rule andthe relation of currents and forces so as to effectively improve the students' learning motility, train the students' initiative for problem thinking and problem solution and improve the learning efficiency.

The invention relates to a cage anti-falling speed reduction buffer device. The cage anti-falling speed reduction buffer device is composed of an electromagnetic induction speed reduction device and an auxiliary inflatable buffer device; an aluminum plate ring is fixed on a cage channel, when the cage falls, a speed sensor or an acceleration sensor exceeds a specified maximum value, automatic circuit conduction is achieved on the speed sensor or the acceleration sensor, the strong current generates a strong magnetic field, according to the Lenz's law, when the cage passes through the aluminumplate ring, the magnetic field of the induced current is always used for blocking the change of the magnetic flux of the induced current, the generated resistance enables the cage to achieve speed reduction to be descended, the cage is descended safely through the step type speed reduction, the safety of the personnel is guaranteed, and the first protection effect is achieved; and a proximity switch enables a trigger to act, the current is sent to an igniter, the sodium nitride propellant contained in the igniter is ignited, then a large amount of harmless gas which takes nitrogen as a main gas can be generated, an air bag is inflated to a full state, and a second protection effect is achieved. According to the cage anti-falling speed reduction buffer device, the design is simple, the weight of the cage cannot be increased, the long-standing technical problem that the cage falls due to the facts that the case suffers from rope breakage, failed braking and failure of an anti-falling device are solved, the work is reliable, the safety performance is high, and the practicability is high.

The invention discloses a method for determining a cross section of an intelligent element of a fire circuit breaker. The method comprises the following steps of deducing a relation of the mass and a sectional area of the intelligent element according to a density formula; deducing a relation of specific heat and mass of a material used by the intelligent element, a rated current intensity of a circuit and a time parameter for disconnecting the circuit when the overcurrent occurs in the circuit according to the sectional area, heat absorption amount, temperature different and Joule-Lenz's law of a resistor and the intelligent element; calculating a sectional area expression of the intelligent element, establishing a sectional model of the intelligent element of the fire circuit breaker, and determining the sectional area of the intelligent element. According to the method, the condition that the sectional area of the intelligent element depends on the square of the rated current under the situation that the type of the material of the intelligent element is determined can be deduced, i.e. the sectional area of the intelligent element is determined by the square of the rated current, and the required sectional area is larger when the rated current is greater.

The invention discloses a multifunctional demonstrator for electromagnetics experiments. The demonstrator comprises a base, a fixing plate, a fixation frame, a rotation frame and a crank. The fixing plate is arranged above the base and rotatably connected with the base, the fixation frame and the rotation frame are fixedly arranged at the two ends of the fixing plate respectively, and the crank ishorizontally arranged on the rotation frame; a U-shaped rack is connected to the crank, opposite heteropolar strip-shaped magnets are arranged at the upper and lower ends of the U-shaped rack, and afirst through hole is formed in the portion, close to the upper portion of the side surface of the rotation frame, of the fixation frame; a first fixing column is arranged on the inner side surface ofthe fixation frame horizontally opposite to the first through hole, a second through hole is formed in the top of the fixation frame, and a second fixing column is arranged on the inner side surfaceof the bottom of the fixation frame vertically opposite to the second through hole. The multifunctional demonstrator for the electromagnetics experiments is simple in structural arrangement, high in visibility and visual and integrates multiple functions, and understanding of students to the Faraday's law of electromagnetic induction, the Lenz's law, the left hand rule and the right hand rule canbe deepened.

The invention relates to the technical field of construction waste, and discloses a construction waste treatment device for automatically detecting screw looseness, the construction waste treatment device comprises a fixing screw and a shell, the top of the shell is fixedly connected with an indicator light, the inner wall of the shell is provided with a fixing groove, and the inner wall of the fixing screw and the outer side close to the fixing groove are fixedly connected with a closing coil. According to the construction waste treatment device for automatically detecting screw looseness, when a fixing screw is loosened due to external vibration, a sliding block can drive a connecting rod to move inwards under the action of a spring, the connecting rod drives a fixing block to move upwards, the relative area between a positive plate and a negative plate is changed to generate current, the current passes through a piezoresistor, and when the fixing screw is loosened, the electric contact is electrified, the electric contact electrifies the electromagnet through the conductive point, the electromagnet generates a magnetic field, the fixing screw is prevented from further loosening according to the Lenz's law and the principle of rejecting leaving, and therefore the problem that the fixing screw leaks out due to loosening is solved.