JPS58153387A - Temperature controlling device - Google Patents

Abstract

PURPOSE:To contrive reduction in power consumption for the titled device by a method wherein the transistor, with which a current is supplied to a Peltier effect element, is operated in an inactive region. CONSTITUTION:The voltage detected by a temperature detector 401 is compared with the reference voltage by a comparator 403, and a binary signal which is in proportion to the result of the above comparison is outputted. This output is supplied to a pair of transistors (TR) 408 and 409, having different polarity respectively, through the intermediaries of reversing device 406 and 407. On the other hand, the output of the comparator 403 is supplied to a pair of transistors 411 and 412, having different polarity, respectively. Accordingly, the direction of current running to the Peltier effect element 413 can be switched in accordance with the magnitude of the output of the detector 401. At this time, as each transistor begins to work in the inactive region, the loss of collector is small, and the power consumption can be reduced too. The same effect as above can also be obtained when a field-effect transistor is used instead of the above transistors.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a temperature control device using a Peltier effect element that generates or absorbs heat depending on the direction of electric current.

[Technical background of the invention]

Among light sources used in optical communication systems, semiconductor radar diodes are often used particularly as light sources for high speed and high output. Compared to light-emitting diodes, semiconductor LED diodes have lower reliability during high-temperature operation (deterioration of service life), light output stability (threshold varies with temperature),
Care must be taken when using the device in terms of the stability of the emission wavelength (changes with temperature), etc.

FIG. 1 shows a schematic configuration of an output circuit of a general semiconductor radar diode. 101 is a semiconductor radar diode, and 102 is a PIN photodiode for monitoring, both of which are housed in the case 101. 104 is A
PC (Out.

The drive circuit 104, which is a semiconductor radar diode drive circuit (hereinafter simply referred to as a drive circuit), includes a Pow@r C@Otority@l ) circuit, and drives the semiconductor radar diode 101 in response to an output electric signal 101iK. , generating a corresponding optical output signal.

This optical output signal is output from the PIN-photodiode 102.
converted into electricity. The drive circuit 104 drives and controls the semiconductor radar diode 101 based on this optical/electrically converted signal (electrical signal) so that the optical output signal becomes a predetermined level.

The optical output signal generated by semiconductor radar diode 101 is sent to optical fiber cable 106. In order to prevent such temperature changes in various characteristics of the semiconductor laser diode, a temperature control device 20 is provided to keep the temperature of the semiconductor laser diode constant in the APC circuit.
0 is set. The temperature control device 200 is a thermistor that detects the temperature of the semiconductor laser diode 101 (actually the temperature of the safety case 102)! (hereinafter referred to as T) 201,
It has a Peltier effect element (hereinafter referred to as P) 202 that absorbs heat (that is, cools) or generates heat (that is, heats) depending on the direction of electric current, and a temperature control section 203. The temperature control unit 203 controls P2O1 according to the detection result of T2O1, and controls the semiconductor radar diode 101 (
Directly controls the temperature of case 1o3).

FIG. 2 shows the circuit configuration of a conventional temperature control device 2000, in which 301 is a non-inverting amplifier and 3o2 is an inverting amplifier. 303.304 is NPN as a source of 'wL flow flowing to P2O1) Lanzosta, 305.306 is NPN for switching) Rungis! It is. Transistors 303, 305 are controlled according to the non-inverting amplifier 3010 output voltage, and F transistors so4. so6 is controlled according to the output voltage of the inverting amplifier SOj. One end of P2O2 is commonly connected to the emitter of transistor 303 and the collector of transistor 306, and the other end is commonly connected to the emitter of transistor 304 and the collector of transistor 305. Therefore, when the voltage generated at T2O1 increases and the output voltage of the non-inverting amplifier 301 increases, that is, when the output voltage of the inverting amplifier 302 decreases,
) The transistor 305 is turned on and the F run raster S06 is turned off. As a result, the transistor 30BSP202,
A current path for transistor 305 is formed and a current is supplied to P2O2. In this case, transistor 303 operates in the active region. On the other hand, when the voltage generated at T2O1 drops, transistor 305 is turned off and transistor 306 is turned on. As a result, transistor 3
A current path of 04, P2O2, and transistor 306 is formed, and a current is supplied to P202 in the opposite direction to the case described above.

In this case, transistor 304 operates in the active region. By switching the direction (and current value) of the current flowing through P2O2, the case 101, that is, the semiconductor laser diode 101 is cooled/heated, and the semiconductor laser diode 101 is maintained at a predetermined temperature.

[Problems with background technology]

In such a conventional temperature control device, as mentioned above, KP
;Transistors 303 and 304 that supply current to to2
Because it operates in the active region, there are the following problems. General KP (Peltier effect element) has low impedance (
10), and about 2 people are required for the current I to control the temperature. Usually, UsV, 12v, 15v, etc. are used as the power supply voltage VCC,
In this case, a low voltage is preferable, so vcc: 5
It is assumed that V. Also, trans ys 1sos, 5
It is assumed that the oetv saturation voltage VCIIAT is 0.5v. Under such general conditions, in a conventional temperature control device, the collector loss P of the lannostar 304 is calculated as follows:
)I. In this case, the maximum value PCMAX of collector loss PC is 1- (Vcc Vczmht)
/ 2 Since it is R, PCMAX - (Vcc - Vczmht ) 2/
4 R=(5-0,5)2/4X1 Medium5. It is clear that the collector loss is extremely large for IW. For this reason, conventional temperature control devices have no choice but to use large-sized transistors. In addition, the heat radiator also had to be large, and there was a drawback that the device could not be built into a shed.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to:
It is an object of the present invention to provide a temperature control device that can reduce power consumption and thereby achieve miniaturization of the device.

[Summary of the invention]

Means for electrically detecting the difference between the temperature of the object to be controlled or the atmosphere to be controlled and the set temperature and outputting a corresponding binary signal is provided, and one of the signals is turned on depending on the logic state of the binary signal. , a pair of transistors with mutually different polarities (first transistor pair), the other of which is turned off;
A pair of transistors forming a pair with the above-mentioned pair of transistors, one of which is turned off and the other of which is turned on in response to a level inversion signal of the value signal, is provided, and according to the logic state of the binary signal. a transistor of one polarity of the first transistor pair, a four-Lutier effect element, a current path of a transistor of a polarity different from the transistor of one polarity of the second transistor pair, or the first
The transistor of the other polarity of the transistor pair, the Peltier effect element, and the Peltier effect element may form one of the current paths of the transistor of the polarity different from the transistor of the other polarity of the second transistor pair. It is designed to switch the direction of the current flowing through the effect element.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the temperature control device 400 shown in FIG. 3, 401 is T (serial setting jl). 402 is a reference voltage power supply that generates a reference voltage. This reference voltage I= is determined by the set temperature and can be arbitrarily varied. 403 is a comparator. Comparator 403 is TiO2
The magnitude of the voltage ET generated in the voltage ET and the reference voltage El is compared, and a binary signal is output according to the comparison result.

Comparator 401 is E! Logic “1” (HIGH) when ≧El
outputs 200 million signals of level), and when Et<Eg, logic @
Outputs a binary signal of 0'' (LOW level).404
, 405 are buffers for driving the binary signal output from the comparator 403 (for example, non-inverted open output TTL 14 , 77 ), 406 and 407 are binary signals output from the comparator 403 This is an inverting power gate (for example, inverting open output TTL gate 7A) for inverting and driving the level.

40B is a PNP that switches (on/on) according to the logic state of the output of the inverting buffer gate 40g) Rungis! , 409 is an inverting transistor, an NPN which switches (on/off) according to the logic state of the output of the fadart 407.
) Ranjisume. 411 is pa, fadate 4o4
PNP that switches depending on the logic state of the output of )
The transistor 412 is an NPN transistor that switches according to the logic state of the output of the transistor 405. PNP) Each work of transistor 408゜411 ξ
, and are connected to a first power supply, for example, a power supply having a power supply voltage VCC. Also, NPN) transistors 409, 41:
Each emitter of 2 is connected to a second power supply, eg ground. 41JUP (Peltier effect element). P41
One end of 3 is PNP) transistor 4 o it, N
pN)・2ndis! Commonly connected to each collector of 409, the other end is PNP) Lansys J 41 J, NP
N) Commonly connected to each collector of the transistor 412. In this embodiment, it is assumed that PdI2 heats (generates heat) when the current I moves in the direction of the arrow Km in the figure, and cools (absorbs heat) when it moves in the direction of the arrow KI51E in the figure.

Next, the operation of one embodiment of the present invention will be explained. In this example, TiO2 is assumed to be a negative characteristic thermistor. In this case, as the target temperature increases, the voltage ET generated at 1401 decreases, and as the target temperature decreases, the voltage ET generated at TiO2 increases. Now, assuming that the target temperature (for example, the temperature of a semiconductor laser diode) is lower than the set temperature, if ET>Es, the output of the comparator 403 becomes logic @"1". The logic "1" output of comparator 403 is converted by power gates 404 and 405 into a logic "1#" signal at a predetermined voltage level. As a result, PNP
) 7Nzoster 411 is in the off state, NPN) Runjisme 412 is in the on state. Further, the level of the logic ""1" output of the comparator 403 is inverted to a logic "0" signal by the inverting buffer darts 406 and 407. As a result, the PNP transistor 408 is in the on state, and the NPN) run nozzle 409 is in the off state. As a result, PNP
) Ranzosumme 40B, P413°NPN) A current path of transistor 412 is formed, and electricity aI flows in the direction of arrow a in the figure through PdI2.

As a result, F) PdI2 generates heat, which heats up, for example, a semiconductor radar diode.

On the other hand, if the target temperature is higher than the set temperature, ET<E
a, and the output of the comparator 403 becomes logic "0#".In this case, contrary to the above case, the PNP) runnostar 411 is on and the NPN) runnostar 412 is off. ) transistor 408 is turned off, and the NPN transistor 409 is turned on.As a result, PNP) transistor 411, P4
1 J, a current path of the NPN transnosmet 409 is formed, and a current flows in the direction indicated by the arrow in PdI2! flows. This is K#) P41J absorbs heat and, for example, a semiconductor radar diode is cooled.

As described above, according to this embodiment, in both heating and cooling cases, PNP) transistor 4o8゜NPN) j resistor 412, and PNP) rannosume 411,
Since the transistors 409 (NPN) are saturated in the on state, (Vcx - VHIIm!) O, S
V) Collector's loss is significantly reduced compared to the conventional method.

That is, according to this embodiment, the power consumption of the entire device can be significantly reduced. Therefore, the control F-lancers 408, 409, 411, 412 may be small power transistors, and the shape may be a small-sized transistor.

Similarly, the transistor's heatsink can be made of a shed.According to this embodiment, the power consumption of the transistor is extremely small as mentioned above, and most of the control power is transferred to the Peltier effect element (P4J, ?). It is efficient because K can be given.

In the above embodiment, the case where the buffers 404 and 405 were provided was explained, but the comparator 403 directly drives the transistors 411 and 412! It's not necessarily necessary if you can do it. In addition, the transistors 408, 4
The transistors 409 and 41 are grounded.
A negative power supply may be connected to each emitter of 2.

Also PNP) transistors 40B, 411 and NPN
) The case where transistors 409 and 412 are used has been described, but P-channel field effect transistors and N
A channel field effect transistor may also be used. In this case, PdI2 has one end commonly connected to each drain of one P-channel and N-channel field effect transistor, and the other end commonly connected to each drain of the other P-channel and N-channel field effect transistor.
Good channel field effect transistor. Note that the object to be controlled is of course not limited to semiconductor laser diodes.

Accordingly, it is possible to reduce power consumption and downsize the device.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an output circuit of a semiconductor radar diode equipped with a temperature control device, FIG. 2 is a circuit configuration diagram of a conventional temperature control device, and FIG. 3 is a circuit configuration diagram showing an embodiment of the present invention. It is a diagram. 200, -400...Temperature control device, 201°401
... Sensor construction star (T, temperature sensor), ZOX. 41 J- Peltier effect element (P), 303 ~ comparator, 406, 407... inversion buffer dart (inverter)
, 4014.411...PNP) Ranjis! .

Claims (1)

[Claims] A temperature detector that detects the temperature of the object to be controlled or the atmosphere to be controlled and converts it into voltage or current, a reference power source that sets a reference voltage or current that corresponds to the set temperature, and the above standards that are set by this reference power source. A comparison circuit that compares the voltage or reference current with the temperature sensor O conversion output and outputs a binary signal according to the comparison result, and an inverter that inverts the level of the binary signal output from the comparison circuit. and a PNP that switches according to the output level of this inverter.
) transistor and an NPN transistor or a P-channel field-effect transistor/and an Nf-channel field-effect transistor pair; Channel O
A second transistor pair consisting of a field effect transistor and an N-channel field effect transistor; one end is commonly connected to each collector or each drain of the second transistor pair, and the other end is connected to each collector of the fa1 transistor pair! Alternatively, a temperature control device comprising: a Peltier effect element that is commonly connected to each drain and generates or absorbs heat depending on the direction of electric current fLO.