Abstract: A smart plug that is partitioned into a plurality of printed circuit boards (PCBs) in a three dimensional manner to reduce its size. Aspects consider the effect of the possible increased internal temperature as the size of the smart plug is reduced. For example, thick metal foils connect various components of a smart plug to reduce heat dissipation within the smart plug. Also, a metal foil may transfer heat from contact metal on a PCB to a side wall of a plastic housing of the smart plug. The smart plug may comprise a computing device that obtains information identifying the attached electrical device and accesses device data about the time duration during which the attached electrical device exhibits transient characteristics. The computing device then uses the accessed data to effectively control the attached electrical device.

Abstract: An automatically balancing type pen recorder, which is compact in size and is highly reliable in operation, comprises an integral servo unit formed of a single printed circuit board which incorporates therein a pen carriage and an automatic balancing mechanism adapted to move a recording chart in a direction perpendicular to the direction of feed of the chart, in response to the magnitude of a measuring signal.

Abstract: A direct current servo motor operates through a toothed belt linkage to drive the pen carriage of a chart recorder. The position of the drive is monitored by a sectored encoder disc on the motor shaft. A pair of optical sensors is located relative to the encoder disc to provide alternately phased transition signals as corresponding edges of the encoder disc sectors pass the sensors when the motor rotates. A microprocessor interrupted by a transition signal goes to a sub-routine that determines which way the encoder disc is rotating and stores a count signal of the corresponding sign in a register. Further the microprocessor compares an input signal with the stored count signal and directs the motor to rotate in the direction that will reduce the difference or error signal to zero thus causing the pen to follow the magnitude of the input signal.

Abstract: Strip chart recorders in which the curve is recorded by means of a rotatable pen (11) which traces the curve in a line of contact (14) being a generatrix of a supporting roller (15), suffer from a plotting error originating from the fact that the ordinate of the curve, which should be proportional to the angle of deflection v of the pen, is proportional to the tangent of said angle. This plotting error, that makes it impossible to carry out measurements on the curve, can be compensated for by incorporating in the position servo, which serves to overcome frictional losses in the recorder, a position sensor of a differential capacitor type (20, 22, 23) the differential capacitance of which, as a function of the angle of deflection v of the pen, is proportional to the tangent of v.

Abstract: In a multi-channel recording instrument, the reference signal of each channel is floating from the ground level. Therefore, one each isolated power supply means must be provided for each channel. However, when the error signal for each channel is transmitted through a photo-coupler, the circuit after the photo-coupler can be isolated from the biasing voltage of the reference signal, and a common power supply can be used for all the stages after the photo-couplers, including servo-motor drivers, of all the channels. This reduces the size and cost of the power supplies as a whole. The non-linear character of the photo-coupler does not cause a positioning error, since the photo-coupler is in the servo-loop having a sufficiently large gain.

Abstract: A slide-wire assembly has a first and a second separately movable contact arranged to engage a semicircular wire-wound resistance element or slide-wire. Clam shell halves of a molded case enclosing the slide-wire assembly are arranged to support the resistance element and a motor drive for one of the slide-wire contacts. The first slide-wire contact is supported on a separately movable element coaxial with a motor drive output shaft but restrained from movement therewith while providing a respective contact adjustment capability. A flexible coupling between the motor output shaft and the driven slide-wire contact enables the molded case to align the contact to apply a contact pressure in a first direction to the second slide-wire contact.

Abstract: A recording device which utilizes a closed loop servo system including a limited rotation motor, i.e. a moving coil galvanometer wherein the moving coil is activated by an input signal such that the rotational movement of a shaft supporting such coil may be translated into a graphic display for recording of the input signal. The device has specific utility in the recording of medical information wherein the input signal is created by the patient's body functions but has widespread alternate utility. The device further includes a transducer construction utilizing a rotational resistance mechanism including a rotating hub to which a contact arm is attached that creates a signal proportional to the position of the coil shaft and utilizes this signal for comparison with the input signal such that the coil position and thus that of the shaft may be corrected.

Abstract: A servo system is disclosed which produces a mechanical position varying in accordance with variations in an electrical input signal. The input signal is applied by an amplifying channel to one input of an error amplifier. The input signal amplifying channel includes an integrating amplifier and a voltage limiting device at the input to the integrating amplifier so that the signal applied to the error amplifier has a limited rate of change. A negative feedback gain determining loop is included in the amplifying channel so that at balance the signal applied to the error amplifier is directly related to the input signal. Applied to the other input of the error amplifier is a signal representative of the positional output from the servo system to form a second rebalanceable loop system.

Abstract: A simplified, compact, inexpensive portable self-balancing recorder to be used in the monitoring of data relating to pollution and/or environmental protection. The recorder is about 650 cubic centimeters in volume and weighs about 5 kilograms; it comprises a minimal number of constitutent components and may be operated without certain costly options (e.g. alarms and controls) if desired. The recorder uses printed circuit board circuitry to monitor and process input signals from the measuring points, and these components can conveniently and easily be removed from the recorder for adjustments or replacements. The recorder includes means for adjusting the ink pressure according to recording conditions and provides an inking system with an hermetically sealed pen point to prevent introduction of bubbles into the ink.

Abstract: A system for recording input electrical signals by positioning galvanometer pen styli relative to a chart paper device in accordance with the input signals. Each pen is mechanically linked to an optical mask. The optical mask in conjunction with an optical system provides a feedback light signal, which is converted to a feedback electrical signal for nulling the input signal. The ink application device includes structure for applying pressure directly to carbon paper, which in turn transfers the carbon or ink to the chart paper, thereby recording clear representations of the electrical signals.