JPH0717394Y2 - Meter drive circuit for detecting temperature in centrifuge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a drive circuit of a meter for measuring a temperature inside a chamber of a centrifuge in which the inside of the chamber is cooled by a cooler.

[Conventional technology]

To keep the rotating sample within the preset cooling temperature range in a centrifuge in which the rotor equipped with the sample is housed in the chamber and the rotor is rapidly accelerated and decelerated for centrifugation. A method has been adopted in which a temperature sensor such as a thermistor is provided in the chamber and a refrigerator for cooling the chamber is controlled by detecting the temperature and turning on and off signals.

By the way, since this temperature control only turns the refrigerator on and off, the temperature detected by the temperature sensor has a hunting waveform having a predetermined temperature range.

FIG. 2 (a) is a waveform diagram of the temperature detected by the temperature sensor,
FIG. 2 (b) is a waveform diagram of ON / OFF signals of the refrigerator corresponding to FIG. 2 (a), showing a hunting waveform when the refrigerator is turned on / off at ± 1 ° C. with respect to the set temperature. .

The hunting phenomenon of the detected temperature is (1) undershoot that occurs after the refrigerator is turned off because the temperature in the chamber is lower than the set temperature, and (2) the refrigerator is turned off and friction heat with air due to rotation of the rotating body. The temperature generated in the chamber rises due to the heat generated by
It is caused by overshoot that occurs when the set temperature is exceeded.

Conventionally, in order to avoid driving the sensed temperature measuring meter with the output of the hunting waveform of such a temperature sensing device, the temperature sensor is prevented from directly adhering to the chamber to make the temperature sensor less sensitive.

[Problems to be solved by the device]

In the conventional device, the temperature detected by the temperature sensor in the chamber has a hunting waveform, and therefore, when inputting the hunting waveform to a meter for measuring the hunting waveform, it is necessary to take a method such as reducing sensitivity.

The present invention solves the problems of the prior art and is capable of suppressing overshoot and undershoot in driving a meter for detecting temperature regardless of where the temperature sensor is installed in the chamber. An object of the present invention is to provide a meter driving circuit for measuring the detected temperature in the above.

[Means for Solving the Problems]

In the present invention, a relay interlocking with an ON / OFF signal for controlling the refrigerator is provided on the output side of the temperature detecting device, and the relay has an a contact that is closed when the refrigerator is turned on and the refrigerator is turned off. And a contact b that is closed when the contact temperature reaches a limit, and the contact a is connected to a meter for measuring the temperature through a diode, while the contact b is for measuring the temperature through an output suppressing circuit composed of a resistor and a capacitor. It is characterized in that it is connected to a meter.

[Action]

According to the present invention, when the refrigerator is turned on and the a contact of the relay is closed, the output from the temperature detection device drives the meter through the diode, and the overshoot of the detected temperature can be avoided.

Also, when the refrigerator is turned off and the b contact of the relay is closed, the meter is driven through the output suppressing circuit consisting of a resistor and a capacitor, and the onshoot of the detected temperature can be avoided.

Therefore, it is possible to suppress overshoot and undershoot of the detected temperature, which results in a hunting waveform, and reduce a large swing of the meter.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an electric circuit diagram of a meter driving circuit for detecting temperature in a centrifuge according to the present embodiment. In the figure, reference numeral 1 is a temperature detecting device having a temperature sensor and the like. A refrigerator (not shown) is controlled to adjust the temperature in the chamber of the centrifuge within a preset temperature range. Reference numeral 2 is a relay that is interlocked with ON / OFF of the refrigerator, and its a contact 2a is closed when the refrigerator is on, and b contact 2b is closed when the refrigerator is off. 3 is a diode, 4 is a resistor, 5 is a capacitor,
6 is a buffer, and 7 is a meter for measuring the detected temperature.

In this embodiment, a diode 3 is interposed on the a-contact 2a side of the relay that interlocks with the on / off operation of the refrigerator, while an output suppressing circuit consisting of a resistor 4 and a capacitor 5 is interposed on the b-contact 2b side to detect the temperature. 7 was driven.

The operation will be described below.

FIG. 2 (c) is a waveform diagram of the detected temperature when this embodiment is applied.

Now, when the refrigerator is turned on, the a contact 2a of the relay 2 is closed, and when the detected temperature is + 1 ° C. above the set temperature, the characteristic of the diode 3 suppresses overshoot as shown in FIG. 2 (c).

Further, when the refrigerator is turned off, the b contact 2b of the relay 2 is closed, and the detected temperature has a flat characteristic at -1 ° C from the set temperature by the resistor 4 and the capacitor 5, and undershoot is suppressed.

In this way, according to this embodiment, overshoot and undershoot can be suppressed, and a large swing of the meter 7 can be reduced.

[Effect of device]

According to the present embodiment, the problems of the prior art can be solved, and overshoot and undershoot can be suppressed in driving the sensed temperature measuring meter regardless of the mounting location of the temperature sensor in the chamber. It is possible to obtain the meter driving circuit for measuring the detected temperature in the centrifuge.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a meter driving circuit for measuring a detected temperature in a centrifuge showing an embodiment of the present invention, FIG. 2 (a) is a waveform diagram of a temperature detected by a conventional temperature sensor, and FIG. FIG. 2B is a waveform diagram of the ON / OFF signal of the refrigerator corresponding to FIG. 1, and FIG. 2C is a waveform diagram of the detected temperature when this embodiment is applied. 1 ... Temperature detector, 2 ... Relay, 2a ... a contact, 2b
B contact, 3 diode, 4 resistance, 5 capacitor, 7 meter for detecting temperature.

Claims (1)

[Scope of utility model registration request] 1. A temperature detecting device is provided in a chamber for accommodating a sample, and a refrigerator for cooling the chamber is preset by controlling an on / off signal from the temperature detecting device. In a centrifuge adapted to be adjusted within a temperature range, a relay interlocking with ON / OFF signals for controlling the refrigerator is provided on the output side of the temperature detection device, and the refrigerator is turned on. An a contact which is closed when the refrigerator is turned off and a b contact which is closed when the refrigerator is turned off are provided. The a contact is connected to a meter for detecting temperature through a diode, while the b contact is formed by a resistor and a capacitor. A meter driving circuit for measuring a detected temperature in a centrifuge, characterized in that it is connected to the meter for measuring a detected temperature via an output suppressing circuit.