JPS6170430A - Electronic thermometer - Google Patents

Abstract

PURPOSE:To obtain a small-sized and cost-reduced electronic thermometer which can detect a temperature only by short charge by using a power supply as the charge of a capacitor. CONSTITUTION:When the terminals 4', 5' of a charging means A are connected to the terminals 4, 5 of the thermometer body B, the capacitor C is instantaneously, e.g. for several sec., charged through a diode D and a resistor R up to a Zenner voltage VZ limited by a battery 6 or a Zenner diode ZD. When a voltage VC applied to both the terminals of the capacitor C exceeds the minimum operation voltage Vth of an operation display means 1, availability of measurement is displayed on the means 1 and then the measurement it made possible. Namely, one charging to the capacitor for 3 or 5sec makes it possible to detect a temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention is an electronic thermometer that operates using a capacitor as 'y1a, and in particular, the amount of electricity that enables at least one temperature measurement with one charge! The present invention relates to an electronic thermometer capable of F product.

[Background Art] An electronic thermometer houses a temperature sensing element such as a thermistor, an arithmetic display unit, a battery, etc., and detects a change in resistance of the thermistor as a change in oscillation frequency, converts it into temperature, and displays the temperature.

Conventionally, as described in Japanese Unexamined Patent Publication No. 58-162822, there are some that use secondary batteries as batteries for supplying power to electronic circuits. These devices can be used for more than one day or several dozen times on a single charge, considering their use in hospitals and the like. *Also, the charging method requires a charging time of 8 hours or more, so a trickle charging method is used in which the battery is stored in a designated case except when it is being used and is constantly charged, which consumes excess power. Moreover, there were restrictions on storage space.

Furthermore, when the battery runs out, it takes at least several minutes for the battery to become usable. Furthermore, rechargeable batteries do not require battery replacement, so they have a waterproof structure, do not require a switch to turn on the power, and normally operate in standby mode, with f It was necessary to have the ability to detect changes and start the operation of the entire circuit.
As described above, home electronic thermometers that can be used to perform measurements only once a day have had problems with miniaturization and cost reduction.

OBJECT OF THE INVENTION 1 The present invention has been provided in view of the above-mentioned problems, and by using the charging charge of a capacitor as a power source, one temperature measurement (such as 3 minutes, 5 minutes, etc. The purpose of the present invention is to provide a small, low-cost electronic thermometer that can be used in the following manner.

[Disclosure of invention] Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 shows a specific circuit diagram, and the thermometer main body B receives a temperature measurement sensor 2 such as a thermistor and an output signal from the temperature measurement sensor 2, and detects, for example, a change in resistance of the thermistor as a change in oscillation frequency, and measures the temperature. It is designed to display by converting it into a display unit, and includes a calculation display means 1 made up of an LSI, a capacitor C that supplies power to the temperature sensor 2 and the calculation display means 1, and a Zener diode for voltage limiting. It is composed of a thermometer ZD and a current limiting resistor R, and each of these members is housed in a housing that constitutes the outer shell of the thermometer body B. The charging means A, which is detachably connected to the thermometer body B and is provided outside the thermometer body B, uses a dry cell 7Ii battery 6 in FIG. By connecting terminals 4' and 5' of charging means A to terminals 4 and 5 of thermometer body B, capacitor C is charged. ! @2
The figure shows another embodiment of the charging means A, which is composed of a step-down transformer T and a diode D1 that rectifies the secondary output of the transformer T.

Now, connect terminal 4.5 of thermometer body B to terminal 4' of charging means A.
, 5' are connected, the capacitor C is rapidly charged, for example, in a few seconds, via the diode D and the resistor R, and as shown in FIG. be done. The voltage Ve across the capacitor C is the minimum operating voltage v of the calculation display means 1.
When th is exceeded, a measurable display is displayed on the calculation display means 1, and measurement becomes possible. In other words, by charging the capacitor C once for several seconds, temperature measurement can be performed once for 3 minutes or 5 minutes.

When the voltage Vc across the capacitor C drops below the minimum operating voltage Vth due to discharge, it becomes impossible to measure body temperature.

Incidentally, the power supply capacitor C used in this embodiment is of the same kind as that used for backing up memories and the like. In addition, the voltage across the capacitor C, Vc, has a large voltage fluctuation compared to a NiCd battery, and its relationship with accuracy is an issue. Therefore, the accuracy is not inferior.

[Effects of the Invention] As described above, the present invention includes a temperature sensor that detects the temperature of a part to be measured, a calculation display unit that calculates and displays the output of the temperature sensor as a temperature, and a temperature measurement sensor and calculation display unit. A capacitor for supplying power to the body of the thermometer is stored inside the thermometer body, and a charging means for charging the capacitor inside the body of the thermometer is provided outside the body of the thermometer, so a capacitor is used. As a result, the capacitor can be charged for a short time, and by using the charge charged in the capacitor as a power source for the temperature measurement sensor and the calculation display means, it is possible to measure the temperature at least once. be effective.

Therefore, the present invention provides an electronic thermometer that is smaller and lower in cost for home use.

[Brief explanation of the drawing]

FIG. 1 is a specific circuit diagram of an embodiment of the present invention, FIG. 2 is a specific circuit diagram of another embodiment of the charging means described above, and FIG. 3 is a characteristic diagram of the voltage across the capacitor C described above. 1 is a calculation display means, 2 is a temperature sensor, A is a charging means,
B indicates the thermometer body.

Claims (2)

[Claims] (1) A temperature sensor that detects the temperature of the area to be measured, a calculation display means that calculates and displays the output of the temperature sensor as temperature, and a capacitor that supplies power to the temperature sensor and calculation display means are installed in the housing of the thermometer body. An electronic thermometer comprising a charging means that is housed inside the thermometer body and is provided with a charging means outside the thermometer body for charging a capacitor within the thermometer body. (2) The electronic thermometer according to claim 1, wherein upon completion of charging the capacitor, the amount of charge for at least one temperature measurement can be accumulated.