초록 ▼

A thermometer is disclosed that utilizes a thermistor as a temperature sensor, to control the period and duty cycle of a multivibrator circuit. A second circuit, controlled by a microcontroller, measures both the charge and discharge times of the oscillation. From the ratio of these parameters, a pr

A thermometer is disclosed that utilizes a thermistor as a temperature sensor, to control the period and duty cycle of a multivibrator circuit. A second circuit, controlled by a microcontroller, measures both the charge and discharge times of the oscillation. From the ratio of these parameters, a precise indication of temperature can be obtained that is independent of temperature variations within the active components and the charging capacitor of the multivibrator circuit. The method is also independent of the value of the charging capacitor. Furthermore, by measuring the same ratio when a fixed resistor is substituted for the thermistor, a cell constant can be derived. The cell constant is used to calibrate the non-ideal response of the multivibrator circuit, thus providing a more accurate measurement of temperature.

대표청구항 ▼

A thermometer is disclosed that utilizes a thermistor as a temperature sensor, to control the period and duty cycle of a multivibrator circuit. A second circuit, controlled by a microcontroller, measures both the charge and discharge times of the oscillation. From the ratio of these parameters, a pr

A thermometer is disclosed that utilizes a thermistor as a temperature sensor, to control the period and duty cycle of a multivibrator circuit. A second circuit, controlled by a microcontroller, measures both the charge and discharge times of the oscillation. From the ratio of these parameters, a precise indication of temperature can be obtained that is independent of temperature variations within the active components and the charging capacitor of the multivibrator circuit. The method is also independent of the value of the charging capacitor. Furthermore, by measuring the same ratio when a fixed resistor is substituted for the thermistor, a cell constant can be derived. The cell constant is used to calibrate the non-ideal response of the multivibrator circuit, thus providing a more accurate measurement of temperature. e light emitting device of claim 15, wherein said means for forming an illuminated body further comprises means for forming multiple illuminated bodies. 17. A method for generating an illuminated body, comprising: feeding a flexible plastic optical guide with a beam from an illumination source; disrupting propagation of light within said optical guide via a scattering surface of said guide, said scattering surface including a non-functional design element so that an illuminated body is produced by light scattered from said scattering surface, whereby said light device provides an artistic and entertaining display. 18. The method of claim 17, further comprising, generating said scattering surface by sculpting a design on said optical guide.