JPH0613207A - Resistor - Google Patents

Abstract

PURPOSE:To obtain a resistor hardly heating and thereby consuming low power during operation as a resistor. CONSTITUTION:The state of a load resistor Ro is detected in the current form to control the generated pulse width in a pulse generator (b) composed of an oscillating circuit and a pulse width modulating circuit by a pulse condition setting up circuit 6 according to the detection results so that the pulse width may be automatically adjusted to specify Reff for specifying the fed current to the load resistor Ro further to specify the voltage. In order to control the pulse width Ts for specifying the Reff, if the pulse width Ts may be fluctuated proportionally to the fluctuation in the load resistor Ro. Furthermore, in order to control the voltage for specifying the same, the pulse width Ts may be controlled so that the Reff may be fluctuated to specify the impressed voltage on the load resistor Ro.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor that generates almost no heat.

[0002]

2. Description of the Prior Art Conventional resistors have been associated with power consumption. That is, when the current flowing through the resistor R is I and the voltage applied to the resistor R is V, the power consumption P is P = R · I ²
= V · I (Watt) Where 1 Watt = 1
J / S.

[0003]

However, the resistance R
When a current I flows through the inside for t (s), heat H = R · I ² t
(J) is generated. Here, the unit of H is J (juille)
Is. Therefore, when P = 1 [W] is substituted into H,
1 (Wh) = 3600 (J) of heat will be generated.

As described above, the conventional resistor is accompanied by heat generation due to power consumption, and the temperature always rises. Therefore, how to dissipate and dissipate the heat generated from this resistor was a big problem. In addition, power consumption is large, which is also a big problem.

[0005]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, a pulse signal output means for outputting a pulse signal having a predetermined effective electric energy corresponding to the equivalent resistance value, and an output pulse signal from the pulse signal output means for supplying a voltage supplied from the first external connection terminal to the third external connection terminal. Pulse conversion means for converting into a pulse signal having an amplitude with the external connection terminal voltage; and output means for rectifying and smoothing the converted pulse signal of the pulse conversion means and outputting the output as a second external connection terminal, The first external connection terminal is connected to the high potential side of the connection circuit, the third external connection terminal is connected to the ground potential side of the connection circuit, and the second external connection terminal is connected to the load of the connection circuit.

For example, when the resistor is used as a pull-up resistor, a load is connected between the first external connection terminal and the second external connection terminal, and when the resistor is used as a pull-down resistor, the second external connection terminal is connected. A load is connected between the connection terminal and the third connection terminal. Alternatively, the pulse conversion means detects the current or voltage at the second connection terminal and feeds this back to modulate the pulse width, thereby varying or varying the load resistance.

[0007]

With the above structure, it is possible to provide a resistor which, while operating as a resistor, hardly generates heat and consumes less power.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings.

[0009]

[First Embodiment] FIG. 1 is a view showing the arrangement of an embodiment according to the present invention. Hereinafter, a schematic configuration of the first embodiment according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 is an oscillation circuit that generates a pulse signal of a predetermined frequency, and 2 is an oscillation circuit 1.
Pulse width modulation circuit for performing pulse width modulation with an arbitrary pulse width on the pulse signal of 3 is a PNP transistor, 4 is an NPN transistor, both transistors are in a totem pole connection, and the collector of the PNP transistor 3 The terminal is connected to the external connection terminal A, the emitter terminal of the NPN transistor 4 is connected to the external connection terminal C, and P
The emitter terminal of the NP transistor 3 is connected to the collector terminal of the NPN transistor 4. Further, the base terminals of both transistors 3 and 4 are connected to the output of the pulse width modulation circuit 2.

Reference numeral 5 denotes a filter circuit arranged between the collector terminal of the PNP transistor 3, the emitter terminal of the NPN transistor 4 and the external connection terminal B, and L shown in FIG.
And an equivalent circuit configuration represented by C, and smoothes a pulse signal described later from the collector terminal of the PNP transistor 3 and the emitter terminal of the NPN transistor 4. A pulse condition setting circuit 6 receives the output (external connection terminal B) of the filter circuit 5 and controls the modulation pulse width of the pulse width modulation circuit 2 according to the input value. That is, the feedback is performed to correct the load fluctuation.

Reference numerals 21 to 23 denote bead filters for reducing the influence of noise or electromagnetic waves caused by pulses on the connection circuit. The bead filters 21 to 23 are provided.
Alternatively, the entire circuit of this embodiment may be shielded by an electromagnetic shielding member. Alternatively, a configuration including both of them may be used. For the electromagnetic shielding member, for example, a ferrite material or the like can be used.

The operating principle of the circuit of this embodiment shown in FIG. 1 will be described below. The resistor of the present embodiment is a resistor based on a concept completely different from the conventional concept of resistance, is an equivalent resistor that apparently has the same function as the conventional resistance, and has a very small heat generation amount H. ing. Then, the resistor of the present embodiment is pulse-driven to equivalently obtain a desired resistance value.

The output pulse signal a from the oscillating circuit 1 outputs a pulse signal having a duty ratio of 1: 1 at a predetermined frequency shown by a in FIG. This pulse signal is applied to the pulse width modulation circuit 2
Then, pulse width modulation is performed on a signal having a pulse width corresponding to the resistance value of this embodiment. For example, the pulse signal c is modulated into a pulse A or a pulse B shown in FIG.
This signal b is a totem-pole connected transistor 3, 4
The pulse signal is converted into a pulse signal indicated by A ′ or B ′ in FIG. 3 and input to the filter circuit 5. In the filter circuit 5, this input signal is smoothed, and a signal indicated by A'or B'in FIG. 3 is shown by hatching "I _1- (I ₁ bar)".
Alternatively, it is converted into a DC current of "I _2- (I ₂ bar)" and output to the external connection terminal B. The above is the basic circuit operation of the circuit of this embodiment.

There are a pull-up type and a pull-down type shown in FIG. 4 as modes used as resistors in an actual circuit. In FIG. 4, Ru is a pull-up resistance,
Rd is a pull-down resistor. The circuit form of the equivalent resistance varies depending on which one is used. Hereinafter, the case where the resistor of this embodiment is used as a pull-up resistor will be described first.

When used as a pull-up resistor, a load resistance is provided between the external connection terminal A and the external connection terminal B of the resistor of FIG. 1, and the external connection terminal C is grounded. That is, it is used in the connected state shown in FIG. In this case, the circuit connection voltage Va is applied to the external connection terminal A, and the high-level potential of the output signals from the oscillation circuit 1 and the pulse width modulation circuit 2 is substantially this voltage Va.

A pulse signal having a high potential level of approximately Va and a period t ₁ shown by a in FIG. 3 is output from the oscillation circuit 1. The duty ratio of the pulse signal may be 50% or any other duty ratio. In response to this pulse signal, the pulse width modulation circuit 2 generates a pulse width-modulated modulation signal having a pulse width with which the present resistor has a desired equivalent resistance value by a built-in volume, and both transistors 3, 4 Output to the base terminal of. This pulse width can be adjusted to any pulse width t ₀ as shown in A or B in FIG.

Transistors 3 and 4 having a totem pole structure
When this modulated signal is input to the base terminal of
Is low, the PNP transistor 3 is off.
The NPN transistor 4 turns on and the pulse goes high.
When the level is set, the PNP transistor 3 is turned on, and the NPN
The transistor 4 is turned off. As a result, the signal line c
High level is I₁Low level is ground level, base
Modulation signal A or B of approximately the same phase as the terminal input pulse signal
A signal having substantially the same timing as is output. This pulse width change
The modulated signal is shown at A'and B '. This signal is a fill
A ', which is rectified / smoothed by the output circuit 5 and is proportional to the pulse width,
And B'shown in slash level₁-(I ₁Bar)
"I₂-(I₂DC current signal (bar)
DC voltage) is output.

The principle of the resistor of this embodiment will be described below.
It can be said that the resistor of this embodiment is equivalently a switch circuit driven by the pulse signal from the pulse width modulation circuit 2. In principle, as shown in FIG. 6, the DC voltage of the power source V _o is equal to that of the switch circuit. This is a configuration in which the load resistance R _o is applied in a pulsed manner by the action. In the case of Figure 6, the peak voltage of the pulse is V _o, which is applied to a pulsed manner to the load resistor, so that the pulse current flows as a result. The average current "I- (I bar)" due to the pulse current at this time can be expressed as follows.

[0019]

[Equation 1]

As a result, the switch portion has an equivalent resistance Ref.
If f, this Reff can be expressed as follows. _{Reff = R O (t s /} t o) (1) also can be expressed also equivalently in cowpea to the circuit of FIG.

The effective resistance of this _{circuit, Reff = {(t s +} t 0) / C} · {1 / (1-e -t0 / RoC)} - given by _{R o (2), {t} 0 / for (R _o C) «1, a _{Reff = R o (t s /} t o) (3).

That is, the above equations (1) and (2) have the same conclusion. From the above, it can be seen that the equivalent resistance is proportional to R _o (t _s / t ₀ ). This is the basic operating principle of the resistor of this embodiment. However, if it is left as it is, Reff depends on the load resistance R _o, and it is difficult to use. Therefore, in the present embodiment, it is desirable to take the following methods.

That is, control is performed so that Reff becomes constant.
Method, load resistance R_OControl so that the supply current to
To control the voltage to be constant, etc.
Conceivable. The basic circuit of these is the circuit shown in FIG.
And the load resistance R_OState of current is detected in the form of current or voltage
The pulse condition setting circuit 6 oscillates based on this detection result.
Pulse composed of circuit 1 and pulse width modulation circuit 2
Automatically adjust the pulse width by controlling the pulse width generated by the generator
Adjust to control Reff to be constant, load resistance R _O
Control so that the current supplied to
To control. Note that the filter has a smooth pulse waveform.
This is for making a smooth waveform.

To keep Reff constant, the load resistance R
_The pulse width T ₀ may be controlled so as to fluctuate in proportion to ± directions according to ± fluctuations of _o . Reff is Reff = R
_It can be specified by the formula of _O (t _s / t _o ), for example, R _o = 10
When it is desired to insert 10 Ω as Reff in the case of Ω, and when t ₀ = 1 ms at V _o = 10 V, t _s = 1 m from the equation Reff = R _O (t _s / t _o ).
It is required to be s. Therefore, it suffices to control the pulse generator so that pulses of t ₀ = 1 ms and t _s = 1 ms are generated.

In this state, the resistance value of R _o changes and R
_In the case of a sharp drop of _O = 1Ω, Reff = 10Ω can be maintained by controlling so that a pulse of t _s = 10 ms is generated. FIG. 9 shows the relationship between the resistance value of R _O and the pulse width of t _s when it is desired to keep R eff = 10Ω constant.
Note that when R _o ≈0, t _s ≈∞, while R _o ≈
When ∞, t _s ≈0.

FIG. 1 shows the relationship between the feed back voltage to the pulse generator by the pulse condition setting circuit 6 and the pulse width t ₀ when V _o = 10 V and R _eff = 10 Ω is constant.
It shows in 0. Overall resistance value R in the circuit of FIG.
Can be represented by R = Reff + R _o . Therefore,
If R _o = 10Ω, then R = 20Ω. V _o = 10
Since V is V, when R _o = 10Ω, the potential at point d in FIG. 8 is 5 V, 5 V is sent to the pulse condition setting circuit 6, and 5 V is input to the pulse condition setting circuit 6. As shown in FIG. 9, t _s = 1 ms from the pulse generator
The pulse is controlled to be output.

If R _o = 1Ω, R = 11Ω, the potential at point d in FIG. 8 becomes 0.9V, 0.9V is sent to the pulse condition setting circuit 6, and the pulse condition setting circuit 6 As shown in FIG. 9, from the pulse generator, t _s = 10
It is controlled so that ms pulse is output. On the other hand, in order to make the current constant, in order to change the load resistance R _o ,
The pulse width T _s may be controlled so that Reff also changes (the voltage value applied to the load resistance R _o is controlled so that the current becomes constant). For example, the reference current value and the load resistance R _o
Is compared with the current value flowing through the control circuit, and control is performed to eliminate the difference. Incidentally, in this case, the maximum voltage that can be applied to the load resistor R _o is up to V _o, is limited to the resistance value of the load resistor.

For example, when R _O = 10 Ω and a constant current I = 0.5 A is desired to flow, V _o = 10V
An example will be described where t ₀ = 1 ms. Note that FIG.
The resistance value R as a whole in the circuit of is R = Reff +
Represented by R _O. I = 0.5 A means V _o = 10
In the case of V, it is necessary that R = 20Ω. R = Reff
+ The Reff = 10Ω than R _O = 20Ω.

The above calculation formula Reff = R_O(T_s/
t_o) Than t₀= 1 ms to t_s= 1ms
It is sought after. Therefore, rather than the pulse generator, t₀= 1
ms, t _s= 1ms pulse is controlled to be generated
Just do it. In this state, R_oResistance value fluctuates and R_O
= 1 Ω, R = Reff + R_O= 2
From 0Ω, Reff = 19Ω. Therefore, the above formula
Than t_s= 11ms pulse is controlled to be generated
Just do it.

Furthermore, in order to make the voltage constant by controlling the pulse width T _0, control such that the voltage applied to the load resistor R _o for variations in the load resistance R _o of Reff becomes constant do it. For example, the reference voltage value is compared with the voltage value at the point d, which is the voltage applied to the load resistance R _o , and control is performed to eliminate the difference. In this case, the minimum load resistance R _o is limited.

The circuit shown in FIG. 1 realizes the above principle by an actual circuit. Even when the circuit shown in FIG. 1 is used as a pull-up resistor as shown in FIG. 5, the heat generation of Ru does not occur in principle, and the saturation voltage of the transistor (about 0.2 V to 0.4 V) is slightly increased. Saturation resistance (several Ω to several tens of Ω)
There is only a slight amount of heat generated by each circuit and a small amount of heat generated by each circuit. However, these heat generations are very small, and a resistor having almost no heat generation can be obtained. Further, since it is not a method of consuming a large current and converting it into heat, the power consumption of the resistor can be suppressed low.

The example in which the resistor of this embodiment is used as a pull-up resistor has been described above. However, this embodiment can also be used as a pull-down resistor. In this case, as shown in FIG. 11, the external connection terminal A is connected to the power source, the external connection terminal B is connected to the load resistance Ro side, and the external connection terminal C is connected to the ground side. Also in this case, the equivalent resistance Rd is uniquely determined according to the set value of the volume of the pulse width modulation circuit 2 as in the case of being used as the pull-up resistance described above, and there is no difference. Even in this case, there is almost no heat generated by the resistor.

As described above, according to this embodiment, it is possible to suppress the power consumption and heat generation amount of the resistor to be low.

[0034]

Second Embodiment The above description has been made on an example in which the principle of the present invention is faithfully made into a circuit. However, the present invention is not limited to the above example, and any configuration can be adopted as long as it achieves a similar equivalent circuit. Although the configuration is the same as that of the first embodiment in principle, a more simplified detailed circuit configuration will be described below with reference to FIG.

FIG. 12 is a detailed circuit diagram of the second embodiment according to the present invention, in which 30 parts surrounded by a broken line is the oscillation circuit 1 of FIG.
This is an oscillation circuit of a variable duty ratio type which also includes a pulse width modulation circuit 2 and a duty ratio that can be arbitrarily changed by a volume VR1. And
TR1, TR2, R1 to R4, C1 and C2 form a CR oscillation circuit. The output pulse signal from the CR oscillating circuit 30 passes through the resistor R5 and the PNP transistor TR.
3 is connected to the base and turns on / off the transistor TR3.
Turns off and outputs an inverted signal of the input signal. The collector of the transistor TR3 is connected via a resistor R6 to the base of an NPN type transistor TR4 which is pulled up by a resistor R7. Further, the transistor TR3 is inverted by the transistor TR4, and a CR oscillator circuit 30 is fed to a filter circuit 35. A pulse signal having a high level voltage as a supply voltage from the external connection terminal A synchronized with the output pulse signal of is supplied. This pulse signal is L1 and C3 of the filter circuit 35.
Is rectified and smoothed by.

Further, the output current or voltage is field-backed to the CR oscillation circuit 30 via the pulse condition setting circuit 6, and the pulse width of the output pulse from the CR oscillation circuit 30 is modulated. As a result, even in the configuration of FIG.
Similar to the first embodiment shown in FIG. 1, when the resistor having the configuration of FIG. 12 is used as a pull-up resistor, the external connection terminal A and the external connection terminal B are used as a load resistance and the external connection terminal C is grounded. . That is, it is used in the connected state shown in FIG. When used as a pull-down resistor, a load resistor is connected between the external connection terminal B and the external connection terminal C, and the external connection terminal A is connected to a power source, and the connection state shown in FIG. 11 is used.

Also in the second embodiment described above, it is possible to provide a resistor which consumes less power and generates less heat.

[0038]

Other Embodiments In the above description, the oscillation frequency of the oscillation pulse signal from the oscillation circuit is fixed, and the duty ratio of the oscillation pulse is changed to change the equivalent resistance value.
However, the present invention is not limited to the above examples,
Instead of the pulse width modulation, an FM modulation circuit may be provided, and the oscillation frequency may be changed according to the equivalent resistance value to change the open output voltage value at the connection terminal B to obtain a desired equivalent resistance value.

When it is not necessary to make the equivalent resistance variable, the resistance may be divided not by the volume but by the fixed resistance. With this configuration, the adjustment process is unnecessary and the cost can be reduced.

[0040]

As described above, according to the present invention, it is possible to provide a resistor that generates almost no heat and consumes less power even though it operates as a resistor.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment according to the present invention.

FIG. 2 is a diagram showing an equivalent circuit of the filter circuit of FIG.

FIG. 3 is a diagram showing a signal waveform of each part of the first embodiment.

FIG. 4 is a diagram showing a form used as a resistor in an actual circuit.

FIG. 5 is a diagram showing a connection example when the resistor of the first embodiment is used as a pull-up resistor.

FIG. 6 is a diagram for explaining the basic principle of the resistor according to the present embodiment.

FIG. 7 is a diagram showing another circuit example equivalently representing the resistor of the present embodiment.

FIG. 8 is a diagram showing an outline of a configuration in which a pulse condition is changed by a feedback in the resistor of the present embodiment.

FIG. 9 is a diagram showing a relationship between a resistance value of a load resistance and a control pulse width in the present embodiment when the resistor of the first embodiment is a constant resistance.

FIG. 10 is a diagram showing the relationship among the resistance value of the load resistance, the feed back voltage, and the control pulse width when the resistor of the first embodiment is a constant resistance.

FIG. 11 is a diagram showing a connection example when the resistor of the first embodiment is used as a pull-down resistor,

FIG. 12 is a circuit diagram of a second embodiment according to the present invention.

[Explanation of symbols]

 1 oscillation circuit 2 pulse width modulation circuit 5,35 filter circuit 6 pulse condition setting circuit 30 CR oscillation circuit

Claims (3)

[Claims] 1. A pulse signal output means for outputting a pulse signal having a predetermined effective power amount corresponding to an equivalent resistance value, and an output pulse signal from the pulse signal output means with a supply voltage from a first external connection terminal. A pulse conversion means for converting into a pulse signal having an amplitude with the third external connection terminal voltage, and an output means for rectifying and smoothing the converted pulse signal of the pulse conversion means and outputting the output as the second external connection terminal. The first external connection terminal is connected to the high potential side of the connection circuit, the third external connection terminal is connected to the ground potential side of the connection circuit, and the second external connection terminal is connected to the load of the connection circuit. A resistor characterized by being connected. 2. The resistor according to claim 1, wherein a load is connected between the first external connection terminal and the second external connection terminal when used as a pull-up resistor, and when used as a pull-down resistor. A resistor, wherein a load is connected between the second external connection terminal and the third connection terminal. 3. The load according to claim 1, wherein the pulse conversion means detects the voltage of the second connection terminal caused by the fluctuation of the load and modulates the pulse width in accordance with the detection result. A resistor having a constant voltage applied to the resistor.