Abstract: A tire pressure indicator which includes a valve stem over-pressure indicator and a valve stem cap under-pressure indicator. The valve stem includes an air porting scheme that releases over-inflation air for escape through a whistling reed configuration. The valve stem cap includes a top translucent panel for coaction with a diaphragm spring contained therebelow. Normal tire pressure distends the diaphragm spring to an upward convex attitude in contact with the underside of the translucent panel to project a visual indicator.

Abstract: A target for providing coded data readable by an imaging apparatus. Location marking means enable location of the target by the imaging apparatus preparatory to an imaging operation, the location marking means having high visibility characteristics e.g. being of retroreflective material to enable identification of the location marking means against a background. Code marking regions of annular shape include circumferentially disposed code markings containing coded data which are imaged by the imaging apparatus to enable recovery of the coded data from the target. The location marking means is located generally centrally of the code marking regions so that identification of the location marking means also locates the center of the code marking regions. The location marking means includes at least one concentric annular region to enable fine location of the center. The code marking regions are rotationally dispersed relative to the center.

Abstract: A method for improving the quality of electrocardiogram (ECG) signals for input to a cardiac monitor and obtained from a patient undergoing magnetic resonance imaging (MRI) wherein the ECG leads attached to the patient are exposed to rapidly changing magnetic fields produced by the MRI which induce relatively high levels of rapid voltage changes in the ECG leads, the method including the steps of conducting the ECG signals having MRI induced noise signals superimposed thereon to the input of a slew rate limiter (SRL) circuit having a preselected maximum slew rate, the circuit providing an output signal having a maximum dv/dt which is slightly greater than the maximum typical ECG dv/dt, connecting the output of the SRL circuit to the input of a low pass filter circuit having an attenuation above the ECG typical fundamental frequency and connecting the output of the low pass filter circuit to a cardiac monitor.

Abstract: An improved coin chute assembly wherein the housing contains a coin receiving opening, a first coin exit opening, a second coin exit opening, and a coin passageway disposed therein and interconnecting the coin receiving opening with the first and second coin exit openings. The coin passageway is characterized as having an upper coin path, a coin receiving section and a coin reject section, the upper coin path being oriented to permit a coin to fall in a substantially downward direction through the chute assembly and thus through the coin receiving section towards the first coin exit opening or through the coin reject section towards the second coin exit opening. A coil having a coin slot formed therethrough is positioned around the upper coin path such that an object traveling through the upper coin path passes through the coin slot.

Abstract: A sonar flasher motor speed control for driving a D.C. electric motor from a varying voltage source. A rotating magnet and coil system generates a first voltage pulse once each revolution of the motor. A capacitor charged through a series resistor in combination with transistor means controlled by the first voltage pulse to generate a ramp voltage once each cycle. The ramp voltage is compared with a reference voltage by means of a voltage comparator, which generates a control second voltage pulse, whenever the ramp voltage exceeds the reference voltage. Transistor amplifier means responsive to said second voltage pulse increases the motor current during the second pulse so as to maintain the speed of the motor relatively constant.