摘要:
A steel hardness measurement system and method of using same are provided for measuring at least one mechanical or magnetic characteristic of a ferromagnetic sample as a function of at least one magnetic characteristic of the sample. A magnetic field generator subjects the sample to a variable external magnetic field. The magnetic field intensity of the magnetic field generated by the magnetic field generating means is measured and a signal sensor is provided for measuring Barkhausen signals from the sample when the sample is subjected to the external magnetic field. A signal processing unit calculates a jump sum rate first moment as a function of the Barkhausen signals measured by the signal sensor and the magnetic field intensity, and for determining the at least one mechanical or magnetic characteristic as a function of the jump sum rate first moment.
摘要:
A circuit integrity detection system for use in detecting the integrity of a sensing wire in a heating pad wherein the integrity of the sensing wire is determined by first driving one end of the sensing wire with a low voltage electrical test signal from a microcontroller, and then checking whether the test signal is present on the other end of the sensing wire, in order to distinguish the test signal from the standard AC line voltage present on the sensing wire, the electrical test signal is preferably of a different frequency than the standard 50-60 Hz AC line voltage. In one embodiment, the test signal frequency is approximately 30 kHz.
摘要:
One or more current sensors are mounted externally of a heating member so as to simplify construction of the heating member. The sensors are particularly useful in safety control circuits for heating members using PTC wire as resistance heating elements.
摘要:
Disclosed is a bath scale for measuring a user's weight having a weight display and a message display driven by a detection-and-display system adapted to provide through the message display one or more substantially non-deductive messages to the user of the bath scale that instruct the user in plain language how to use the scale.
摘要:
A circuit is provided for powering a small electrical appliance load. In one embodiment the circuit includes a power output control device such as a triac to supply power to the load. A thermal fuse is placed in series with the triac. A resistor is placed in thermal proximity to the thermal fuse. A switching device such as a transistor is provided to turn on the resistor. A microcomputer controller monitors a short fault condition of the triac. The microcomputer controller turns on the transistor upon detecting a short fault condition in the triac.
摘要:
A humidifier has a first sealable reservoir feeding water to a second reservoir communicating with ambient atmosphere. A blower is adapted to blow a stream of air through the humidifier to ambient atmosphere, such that the stream of air picks up water vapor from any water that may be in the second reservoir. A feeder valve feeds a quickly-evaporable quantity of water from the first reservoir into the second reservoir. The quickly-evaporable quantity of water in the second reservoir is substantially smaller than the water capacity of the first reservoir. A dry-out mechanism shuts off the feeder valve upon a user command and continues to run the blower at least until the quickly-evaporable quantity of water has evaporated to an extent effective in inhibiting the growth of microorganisms in the microorganism-vulnerable reservoir.
摘要:
The invention provides a method for a friction stir welding process, which comprises the steps of conventional stir welding—including applying friction to the areas of the workpiece to be welded by means of a rotating tool (20) that has a large shoulder that is pressed downwards on the workpiece and has a probe inserted into the material to be welded. The tool being advanced along the weld line. The method additionally comprises generating a laser beam (28) and collimating and focusing said beam on the workpiece in the weld region (29) ahead of the rotating tool. The invention also provides an apparatus for friction stir welding, which comprises the elements of conventional stir welding apparatus—including a rotating tool (20) that has a large shoulder and has a probe for insertion into the material to be welded, a mechanism for holding the tool and rotating and advancing it, a mechanism for pressing the tool shoulder downwards on the workpiece, and a mechanism for clamping the workpieces. The apparatus further comprises a laser beam generator (25), a laser beam conduit (26), preferably consisting of optical fibers, and collimator (28) and focusing optics for focusing the laser beam on the desired area of the workpiece.