CN104977965A - Steady state constant current circuit structure - Google Patents
Steady state constant current circuit structure Download PDFInfo
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- CN104977965A CN104977965A CN201510398270.7A CN201510398270A CN104977965A CN 104977965 A CN104977965 A CN 104977965A CN 201510398270 A CN201510398270 A CN 201510398270A CN 104977965 A CN104977965 A CN 104977965A
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- constant current
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Abstract
The invention relates to a steady state constant current circuit structure comprising a constant current transistor and further a positive temperature coefficient thermistor. The positive temperature coefficient thermistor is in a serial connection with the constant current transistor. In the steady state constant current circuit structure, the positive temperature coefficient thermistor is in a serial connection with the constant current transistor; when circuit voltage rises, constant current IH rises, too, and heating resistance of the positive temperature coefficient thermistor also rises up due to a R-I feature, so currents can properly decreases and stability of the constant currents can be guaranteed; and meanwhile, when voltage surpasses a constant current pipe and positively breakdown voltage VB and oversizes and the constant current pipe loses constant current features, the positive temperature coefficient thermistor value rises to the maximum, circuit currents are reduced and electric equipment can be protected.
Description
Technical field
The application relates to circuit structure field, particularly constant current circuit structure field, specifically refers to a kind of stable state constant current circuit structure.
Background technology
Constant current tube is a kind of semiconductor devices being often used in driving LED or other electronic original part, and being characterized in can providing when mains voltage variations is that constant electric current is to protect the LED or other electronic original part that drive.Constant current tube is equivalent to constant current source or the peak inrush current limiting circuit of a big current, even if there is the situation that supply voltage supply instability or pull-up resistor alter a great deal, it can guarantee that supply current is stablized.Therefore, constant current tube is widely used in the protection circuit of constant current source, source of stable pressure, amplifier and electronic device.
But, in existing constant current tube application mode, constant current tube application circuit must have resistance to be that the resistance of 101 ~ 104 Ω could use by extraneous accurately string, such as steady current IH is 1.5mA (test voltage is 10V), when voltage or current anomaly appear in circuit, when circuit voltage rises to VB, then IH non-fully is constant, but there is undulating quantity Δ I.Like this, on the one hand, the needs to the higher equipment of stabilized current characteristic requirement cannot just be met; On the other hand, when voltage exceedes forward break down voltage VB (1.2IH), constant current tube can lose constant-current characteristics, if now voltage or electric current excessive, then easily directly damage constant current tube, potential safety hazard produced to whole application circuit.
Summary of the invention
The object of the application overcomes above-mentioned shortcoming of the prior art, provides a kind of constant-current characteristics more stable, and constant current tube can be avoided damaged, and structure is simple, with low cost, widely used stable constant current circuit structure.
In order to realize above-mentioned object, the stable constant current circuit structure of the application has following formation:
This stable state constant current circuit structure comprises a constant current transistor, and its principal feature is, this stable state constant current circuit structure also comprises a posistor, this posistor and constant current transistor series.
Constant current transistor described in this stable state constant current circuit structure is current regulator diode, and described posistor is connected in series in the negative pole of this current regulator diode.
This stable state constant current circuit structure can also comprise a resistance, and this resistance and the circuit be serially connected with between diode cathode and posistor are in parallel.
The described circuit be connected between diode cathode and posistor is a section lead.
Described resistance is adjustable resistance.
Constant current transistor described in this stable state constant current circuit structure is constant current triode, the first end of described posistor connects the negative electrode of this constant current triode, the control pole of the constant current triode described in the second end connection of this posistor.
The control pole of described constant current triode and the second end of posistor can also equal ground connection.
This stable state constant current circuit structure can also comprise a resistance, and this resistance and the circuit be serially connected with between described triode negative electrode and posistor are in parallel.
The described circuit be connected between triode negative electrode and posistor is a section lead.
Described resistance is adjustable resistance.
Have employed the stable state constant current circuit structure of this application, due to posistor is connected with constant current tube, when circuit voltage rises, when steady current IH is also raised, posistor correspondingly can raise heating resistor due to its R-I characteristic, electric current is suitably reduced, ensure that the constant current performance of constant current tube, more effectively stabilize circuital current; Simultaneously; when voltage exceedes constant current tube forward break down voltage VB (1.2IH) and excessive; when making constant current tube can lose constant-current characteristics, posistor can local pyrexia that self-resistance is risen to is high, thus significantly reduces circuital current and protection circuit.After fault is repaired, posistor self resistance is down to initial value, and can reuse repeatedly with constant current tube.This application stable performance, structure is simple, with low cost and have wide range of applications.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of a kind of embodiment of the stable state constant current circuit structure of the application.
Fig. 2 is the schematic diagram of a kind of preferred implementation of the stable state constant current circuit structure of the application.
Fig. 3 is the schematic diagram of the another kind of embodiment of the stable state constant current circuit structure of the application.
Fig. 4 is the schematic diagram of the another kind of preferred implementation of the stable state constant current circuit structure of the application.
Fig. 5 is the R-I performance diagram of the posistor in the application.
Embodiment
In order to the technology contents of the application more clearly can be understood, describe in detail especially exemplified by following examples.
Referring to shown in Fig. 1, is a kind of embodiment of the stable state constant current circuit structure of the application.This stable state constant current circuit structure comprises a current regulator diode 1, and also comprise a posistor 2, this posistor 2 is connected in series in the negative pole of this current regulator diode 1.
This embodiment is applied to LED and drives.Wherein, the parameter of current regulator diode 1 is: steady current IH=4.0 ~ 4.95mA (test voltage is 10V), initial constant current voltage Vk≤3, motional impedance ZD=150K Ω, the highest use voltage V=80V, control electric current are 50ns than KC=lsov/IH≤1.1, pulse rise or fall time; The parameter of posistor 2 is: maintain electric current lhold=4.0mA, ceiling voltage Vmax=100V, maximum value R=1500 Ω.
In a kind of preferred implementation of the application, as shown in Figure 2, the above-mentioned stable state constant current circuit structure with current regulator diode 1 can also comprise an adjustable resistance 3, this adjustable resistance 3 and the circuit be serially connected with between diode 1 negative pole and posistor 2 are in parallel, namely, one end of this adjustable resistance 3 connects the negative pole of current regulator diode 1, and its other end is connected to side posistor 2 connecting current regulator diode 1 negative pole.The described circuit be serially connected with between diode 1 negative pole and posistor 2 is a section lead, and this section lead has certain resistance value (less).Change this adjustable resistance 3, the parallel resistance value of itself and described wire can be changed in less scope, for resistor trimming when dispatching from the factory, make whole stable state constant current circuit structure obtain more accurate steady current IH.
This embodiment is applied to the constant current source providing handheld device, and its constant current performance is better.Wherein, the parameter of current regulator diode 1 is: steady current IH=6.3 ~ 6.8mA (test voltage is 10V), initial constant current voltage Vk≤3, motional impedance ZD=150K Ω, the highest use voltage V=80V, control electric current are 50ns than KC=lsov/IH≤1.1, pulse rise or fall time; The parameter of posistor 2 is: maintain electric current lhold=6.3mA, ceiling voltage Vmax=100V, maximum value R=1000 Ω.
In the another kind of embodiment of the application, as shown in Figure 3, this stable state constant current circuit structure comprises a constant current triode 4, also comprise a posistor 2, the first end of this posistor 2 connects the negative electrode of this constant current triode 4, the control pole of the constant current triode 4 described in the second end connection of this posistor 2, in the present embodiment, the control pole of described constant current triode 4 and the equal ground connection of the second end of posistor 2.
This embodiment is applied to as digital product provides constant current source.Wherein, the parameter of constant current triode 4 is: the continuous current triode 1 that steady current IH=1.5 ~ 2.5mA (test voltage is 10V), initial constant current voltage Vk≤5, motional impedance ZD=150K Ω, the highest use voltage V=80V, control electric current are 50ns than KC=lsov/IH≤1.05, pulse rise or fall time; The parameter of posistor 2 is: maintain electric current lhold=1.5mA, ceiling voltage Vmax=100V, maximum value R=5000 Ω.
In the another kind of preferred implementation of the application, as shown in Figure 4, the above-mentioned stable state constant current circuit structure with constant current triode 4 can also comprise an adjustable resistance 3, this adjustable resistance 3 and the circuit be serially connected with between triode 4 negative electrode and posistor 2 are in parallel, namely, one end of this adjustable resistance 3 connects the negative electrode of constant current triode 4, and the other end is connected to the first end of posistor 2.Circuit between the described negative electrode being serially connected with triode 4 and posistor 2 is a section lead, and this section lead has certain resistance value.Change this adjustable resistance 3, the parallel resistance value of this adjustable resistance and described wire can be changed in less scope, for resistor trimming when dispatching from the factory, make whole stable state constant current circuit structure obtain more accurate steady current IH.
This embodiment is applied to as micromachine provides constant current source, and its constant-current characteristics is better, and voltage range is wider.Wherein, the parameter of constant current triode 4 is: steady current IH=6.3 ~ 6.8mA (test voltage is 10V), initial constant current voltage Vk≤35, motional impedance ZD=200K Ω, the highest use voltage V=80V, control electric current are 50ns than KC=lsov/IH≤1.05, pulse rise or fall time; The parameter of posistor 2 is: maintain electric current lhold=6.3mA, ceiling voltage Vmax=100V, maximum value R=1000 Ω.
In the application of the application, the stable state constant current circuit structure access power circuit that the application is provided.Wherein connected posistor has its intrinsic R-I characteristic, as shown in Figure 5, when circuital current is in AB interval, the resistance of this posistor slowly can rise with the rising of electric current, and after being greater than B point, its resistance can rise suddenly.So when the steady current IH of the constant current tube in this stable state constant current circuit structure produces undulating quantity Δ I because of voltage rise, this posistor correspondingly can slowly improve its resistance, thus reduces Δ I, makes steady current IH more stable.On the other hand, when voltage exceedes constant current tube forward break down voltage VB and excessive, when making constant current tube lose its constant-current characteristics, posistor is due to its R-I characteristic, meeting local pyrexia also makes self-resistance suddenly raise, thus reduce circuital current, avoid the impact that connect consumer is subject to excess current.In addition, adjustable resistance is accessed in the stable state constant current circuit structure that the application provides, make it and be connected to the conductor in parallel between constant current transistor and posistor, by regulating this adjustable resistance, to adjust the parallel resistance value of this adjustable resistance and wire in less scope, for finely tuning the resistance of whole circuit when dispatching from the factory, make whole stable state constant current circuit structure obtain more accurate steady current IH, thus meet demand steady current being required to higher consumer.
Have employed the stable state constant current circuit structure of this application, due to posistor is connected with constant current tube, when circuit voltage rises, when steady current IH is also raised, posistor correspondingly can raise heating resistor due to its R-I characteristic, electric current is suitably reduced, ensure that the constant current performance of constant current tube, more effectively stabilize circuital current; Simultaneously; when voltage exceedes constant current tube forward break down voltage VB (1.2IH) and excessive; when constant current tube can lose constant-current characteristics, posistor can local pyrexia that self-resistance is risen to is high, thus significantly reduces circuital current and protection circuit.After fault is repaired, posistor self resistance is down to initial value, and can reuse repeatedly with constant current tube.This application stable performance, structure is simple, with low cost and have wide range of applications.
Claims (5)
1. a stable state constant current circuit structure, comprise a constant current transistor, it is characterized in that, described stable state constant current circuit structure also comprises a posistor, described posistor and described constant current transistor series.
2. stable state constant current circuit structure according to claim 1, is characterized in that, described constant current transistor is current regulator diode, and described posistor is connected in series in the negative pole of described current regulator diode.
3. stable state constant current circuit structure according to claim 2, is characterized in that, described circuit structure also comprises a resistance, and described resistance and the circuit be serially connected with between described diode cathode and posistor are in parallel.
4. stable state constant current circuit structure according to claim 3, is characterized in that, the described circuit be serially connected with between diode cathode and posistor is a section lead.
5. stable state constant current circuit structure according to claim 1, it is characterized in that, described constant current transistor is constant current triode, the negative electrode of the constant current triode described in first end connection of described posistor, the control pole of the constant current triode described in the second end connection of this posistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510398270.7A CN104977965A (en) | 2015-06-30 | 2015-06-30 | Steady state constant current circuit structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510398270.7A CN104977965A (en) | 2015-06-30 | 2015-06-30 | Steady state constant current circuit structure |
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| Publication Number | Publication Date |
|---|---|
| CN104977965A true CN104977965A (en) | 2015-10-14 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201510398270.7A Pending CN104977965A (en) | 2015-06-30 | 2015-06-30 | Steady state constant current circuit structure |
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| CN (1) | CN104977965A (en) |
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2015
- 2015-06-30 CN CN201510398270.7A patent/CN104977965A/en active Pending
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Addressee: Wang Yongshun Document name: Notification of Publication of the Application for Invention |
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| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20151014 |