JPH05334865A - Temperature control method for electronic equipment - Google Patents

Abstract

PURPOSE:To provide a control method for temperature which can perform compensation of a sensor section detecting temperature without using much time and cost in a CD deck device with an amplifier and the other electronic equipment. CONSTITUTION:A sensor section 6 which measures temperature and a control section 2 which performs the prescribed control operation in accordance with the prescribed temperature previously set are provided. The control section 2 sets different plural temperature in rising process of temperature, and finds an elapsed time from measuring of one set temperature to measuring of the other higher set temperature. Difference between the elapsed time found and the prescribed time previously set, and the prescribed temperature is compensated in accordance with the found difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control method for electronic equipment.

[0002]

2. Description of the Related Art Conventionally, various methods have been used for controlling the temperature of electronic equipment. For example, a CD with an amplifier
In the deck device (hereinafter referred to as "CD device"), the DISC is affected by the heat generated from the amplifier and other parts and the ambient temperature during the reproduction of the DISC. As is well known, since DISC is made of resin, when temperature rises, distortion occurs due to heat, which not only adversely affects the reproduced sound but also sometimes damages the CD device itself.

Therefore, the DISC which drives the DISC in rotation
A sensor for temperature measurement is provided in the drive unit or in the vicinity thereof,
When the temperature exceeds the specified temperature, the playback operation of DISC is stopped and the volume for adjusting the volume is minimized.
I try not to make annoying noise from the speaker.

FIG. 5 shows the structure of a sensor section using a thermistor for the above sensor. In FIG. 5, a fixed resistor R ₁ , a thermistor R _S, and a variable resistor R ₂ are connected in series to divide a power supply voltage of 5V. Since the thermistor R _S has a negative resistance characteristic with respect to temperature,
By detecting the voltage at the terminal A at the connection point between the fixed resistor R ₁ and the thermistor R _S , the temperature is measured by referring to the voltage / temperature conversion table stored in the storage unit such as the memory in the CD device. can do.

FIG. 6 shows a part of a flow chart of the operation of the control unit when the conventional temperature control method for a CD device is applied. In FIG. 6, it is determined whether or not the temperature of the sensor unit is 80 ° C. or higher (step S21).
When the temperature rises above ℃, the drive control of the DISC is stopped (step S22), and the volume adjustment volume is set to -∞.
dB, that is, the minimum value (step S23).

As described above, even in the above conventional temperature control method, when the temperature reaches a predetermined temperature, the operation of the electronic device is stopped to prevent malfunction and damage to the device due to heat. it can.

[0007]

However, in the above-mentioned conventional temperature control method, there is a problem that the temperature cannot be accurately measured due to the variation in the characteristic of the resistance value with respect to the temperature of the thermistor R _S. Generally, the resistance tolerance of the thermistor is larger than the tolerance of normal resistance. Further, in the resistance temperature characteristic, the allowable range of the so-called B constant used for calculating the resistance value at the target temperature is ± 10.
%, The variable resistor R ₂ must be adjusted for correction.

The following method is available as an example of calculating the correction value.

The resistance value of the thermistor R _S at 25 ° C. is set to 1 k
Ω (tolerance ± 10%), B constant 3500 (tolerance ± 10
%), The thermistor R _S at 50 ° C. is calculated. First, the calculation formula of the B constant is expressed as (Equation 1).

[0010]

[Equation 1] In (Equation 1), R ₂₅ and R ₅₀ are resistance values of the thermistor at 25 ° C. and 50 ° C., respectively, and T ₂₅ and T ₅₀ are numerical values representing 25 ° C. and 50 ° C. in Fahrenheit, respectively. .. The formula for calculating R ₅₀ from (Equation 1) is (Equation 2)
, R ₅₀ = 403.26Ω is obtained.

[0011]

[Equation 2] In FIG. 5, assuming that R ₁ = 1 kΩ and R ₂ = 500 Ω, the voltage V _{A at the} terminal A becomes V _A = 2.37v.

Here, R ₂₅ is 1.1 kΩ (tolerance +10
%) And B constant 3150 (allowable width −10%), the thermistor R ′ ₅₀ is R ′ ₅₀ = 48 from (Equation 2).
It becomes 5.76Ω.

[0013] V _A = A value of 2.37v a normal detection voltage at 50 ° C., the value of the above R _'50 485.76Ω
Is a variation due to the tolerance of the thermistor R _S , so the variable resistor R ₂ is adjusted for correction. The correction value Δ
R is ΔR = R ′ ₅₀ −R ₅₀ = 485.76Ω−403.
26Ω = 82.5Ω. Thus, the variable resistor R 'after the correction resistance value of _{2 · R' 2 = R 2 -ΔR} = 417.5Ω
Becomes

On the other hand, without such correction, the above R '
_When the value of 50 is regarded as the regular resistance value at 50 ° C,
The voltage V _{A at the} terminal V becomes V _A = 2.48v,
This value corresponds to the detection voltage of 44.5 ° C. in the normal case. That is, the control unit measures a temperature lower than the actual temperature, and even when the actual temperature exceeds the specified temperature to be protected, the DISC reproducing operation is continued, so that the reproduced sound is deteriorated. Or damage to the device. Therefore, it is indispensable to adjust the variable resistance as described above to correct the variation of the thermistor.

However, in order to make such a correction, it is necessary to set a predetermined temperature environment in the CD device and adjust the variable resistance for each one to make the correction.
The time and cost required for the process will be enormous. Therefore, there is a problem that not only the product cost rises but also the efficiency at the time of mass production decreases.

The present invention solves the above-mentioned conventional problems, and provides a temperature control method capable of correcting the temperature of a sensor unit in a CD device or other electronic apparatus without spending time and money. With the goal.

[0017]

In order to achieve the above object, the present invention comprises a temperature detecting means for measuring a temperature and a control means for performing a predetermined control operation according to a predetermined temperature set in advance, The control means sets a plurality of different temperatures in the temperature rising process, calculates the elapsed time from the measurement of one set temperature to the measurement of another higher set temperature, and the calculated elapsed time is predetermined. The difference from the predetermined time is calculated, and the predetermined temperature is corrected according to the calculated difference.

[0018]

Therefore, according to the present invention, the time required from a certain first temperature to another particular second temperature is measured, and this time required is compared with a reference time. Since the preset temperature is corrected, the time and cost for the correction can be greatly reduced.

[0019]

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

FIG. 1 is a block diagram of a CD device to which the temperature control method according to the present invention is applied. In FIG. 1, reference numeral 1 denotes a DISC that rotationally drives a DISC (not shown).
Reference numeral 2 denotes a control unit that controls the operation of the DISC unit 1 via the signal line 11. 3 is a volume, the signal line 12
The volume of the reproduced sound (in this case, an analog signal) obtained from the DISC unit 1 via the signal line 13 is adjusted in response to a command from the control unit 2 via. Reference numeral 4 is an amplifier unit that amplifies the analog audio signal adjusted by the volume 3, and reference numeral 5 is a speaker that emits audio according to the audio signal output from the amplifier unit 4. Reference numeral 6 denotes a temperature measuring sensor provided near the DISC unit 1.

In the operation of the configuration shown in FIG. 1, the operation of the rotational drive of the DISC and the operation of the processing of the reproduction signal obtained from the DISC are widely known, and the description thereof will be omitted. The operation of the temperature control will be described. To do.

In the amplifier section 4 of FIG. 1, heat is generated particularly in the output stage thereof, and the heat is also conducted to the DISC section 1.
The sensor 6 senses the temperature due to this heat with a thermistor (not shown), and supplies a detection voltage according to the temperature to the control unit 2 as in the conventional example. In this embodiment,
In the process of increasing the temperature, the temperature control described below is performed assuming two different set temperatures.

The characteristic curve A in FIG. 2 shows the characteristic of the temperature rise over time. This characteristic is a standard characteristic obtained by conducting a quantitative test by preparing some thermistors used in the sensor unit 6 having a regular temperature change characteristic. In FIG. 2, points a and b are temperature measurement points in this standard characteristic, and the respective temperatures are T ₁ and T ₂ . Also, point c is DI
It shows the point of T ₃ which is the temperature at which the drive of the SC is stopped. Here, the time from the point a to the point b, that is, the time Δts for increasing the temperature T ₁ to the temperature T ₂ is set as the standard time.

By the way, since the temperature characteristic of the thermistor varies, the elapsed time Δt from the temperature T ₁ to the temperature T ₂ becomes shorter or longer than the standard time Δts. FIG. 3 shows the deviation of the measurement points when the same temperature is applied. In FIG. 3, T ′ ₁ and T ′ ₂ at points a ′ and b ′ are temperatures lower than T ₁ and T ₂ obtained by the quantitative test and show characteristics up to that time. Yes, this case is referred to as case 1.

Further, T " ₁ and T" ₂ at the points a "and b" are cases in which they show characteristics up to those times at temperatures higher than T ₁ and T _{2. In} this case, Is case 2.

In the case of Case 1, a temperature lower than the actual temperature is measured. In this case, the elapsed time Δt 'from the point a'to the point b'and the standard time Δts are Δt. Since the relation of '<Δts is established, the control unit 2 determines that the temperature is lower than that of the standard sensor characteristic, and the control point of the next limit temperature T ₃ is defined as Δt'. The temperature is set higher by the ratio of the difference of Δts. That is, the sensor characteristic curve of FIG. 3, a standard and consisting point c of the temperature T _3, is set to a temperature T _'3 of the time axis (Δts-Δt') by the correction correction point c '.

On the other hand, the case 2 is a case where a temperature higher than the actual temperature is measured, and in this case, the elapsed time Δt ″ from the point a ″ to the point b ″ and the standard time Δts.
Since the relationship of Δts <Δt ″ is established, the control unit 2 determines that the temperature is higher than in the case where the sensor characteristic is standard, and the control point of the limit temperature T ₃ is set to Δts and Δt. The temperature is set lower by the ratio of the difference. That is, on the sensor characteristic curve of FIG. 3, from the point c which becomes the standard of the temperature T ₃ , the time axis is (Δ
The temperature is set to T ″ ₃ at the correction point c ″ corrected by t ″ −Δts).

By performing the above temperature control, it is possible to reduce the error in temperature measurement due to the variation in the characteristics of the sensor.

FIG. 4 is an operation flowchart showing a temperature control routine executed by the control unit 2. When the control unit 2 shifts from the main routine to the temperature control routine, the control unit 2 measures the temperature based on the detected voltage detected by the sensor unit 6 and determines whether or not the measured temperature has reached T ₁ (step S1). ). When T ₁ is reached, measurement of Δt time is started (step S2), and it is determined whether the measured temperature is T ₂ (step S3). When T ₂ is reached, the measurement of Δt time is completed (step S4). Next, the measured elapsed time Δt and the standard time Δts are compared (step S5), and if Δt <Δts, the difference (Δts-Δt) is calculated (step S6) to obtain the standard temperature T ₃ . setting the temperature T _'3 obtained by adding the ratio of the difference (step S7). After that setting, the sensor unit 6
Measurement temperature at to determine whether becomes T _'3 (step S8).

On the other hand, in step S5, Δt <Δt
If it is not s, the difference (Δt−Δts) is calculated (step S9), and the temperature T ″ _{3 obtained} by subtracting the standard temperature T ₃ by the ratio of the difference is set (step S10). It is determined whether or not the measured temperature has reached T ″ ₃ (step S11).

[0031] When the measured temperature in the step S8 becomes T _'3, or when the measured temperature becomes T _"3 in step S11, it stops the DISC control (step S12), the given command to the volume 3 Then, the adjustment is set to −∞ dB, that is, the minimum volume (step S13).

Since the control unit 2 performs not only this temperature control routine but also other control operations, the process of determining the measured temperature in the flowchart of FIG. In the case), the process returns to the main routine, but since it is not directly related to the description of the present invention, it is omitted for simplicity.

In this embodiment, FIG. 2 and FIG.
The characteristic curve of the temperature rise shown in Fig. 3 was obtained by a quantitative test. However, in the design stage of the CD device, parts that are sources of heat are dispersedly arranged, and holes for heat dissipation are provided in the housing. By taking measures, the temperature rise characteristics can be kept within a certain range even during actual operation other than the test.

[0034]

As described above, the temperature control method according to the present invention sets a plurality of different temperatures in the course of temperature rise and progresses from the measurement of one set temperature to the measurement of another higher set temperature. A sensor unit that detects the temperature without performing temperature correction during mass production one by one by calculating the difference between the time and a predetermined time and correcting the predetermined temperature according to the calculated difference. The effect is that the correction can be performed without time and cost.

[Brief description of drawings]

FIG. 1 is a CD with an amplifier to which a temperature control method of the present invention is applied
It is a block diagram of a deck device.

FIG. 2 is a diagram showing standard temperature rising characteristics preset by the temperature control method of the present invention.

FIG. 3 is a diagram illustrating correction by the temperature control method of the present invention.

4 is a flow chart showing an operation of temperature control executed by the control unit of FIG.

FIG. 5 is a diagram showing a configuration of a sensor unit that measures temperature.

FIG. 6 is a diagram showing a part of a flowchart showing a conventional temperature control method.

[Explanation of symbols]

 1 DISC section 2 Control section 3 Volume 4 Amplifier section 5 Speaker 6 Sensor section

Claims (1)

[Claims] 1. A temperature detecting means for measuring a temperature, and a control means for performing a predetermined control operation according to a predetermined temperature set in advance, wherein the control means sets a plurality of different temperatures in a temperature rising process. Then, the elapsed time from the measurement of one set temperature to the measurement of another higher set temperature is calculated, the difference between the elapsed time and a predetermined time period is calculated, and the predetermined value is calculated according to the difference. A temperature control method for an electronic device, which comprises correcting the temperature.