CN219041386U - Power-down self-turn-off circuit of servo driver switching power supply - Google Patents
Power-down self-turn-off circuit of servo driver switching power supply Download PDFInfo
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- CN219041386U CN219041386U CN202222562758.7U CN202222562758U CN219041386U CN 219041386 U CN219041386 U CN 219041386U CN 202222562758 U CN202222562758 U CN 202222562758U CN 219041386 U CN219041386 U CN 219041386U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The utility model provides a power-down self-turn-off circuit of a switching power supply of a servo driver, wherein a switching power supply control chip is connected with a power supply RS of the servo driver through a turn-off circuit, the turn-off circuit supplies power to the switching power supply control chip from the power supply RS, the turn-off circuit sequentially comprises a power on-off detection circuit and a switching circuit, when the power on-off detection circuit detects that the power supply RS supplies power normally, the switching circuit is turned off, and when the power on-off detection circuit detects that the power supply RS is turned off, the switching circuit is turned on, and the COMP pin of the switching power supply control chip is pulled down so as to turn off the switching power supply. The scheme provides a power-down self-turn-off circuit, realizes the power-off detection effect on the power supply RS through the detection circuit, and realizes the effect of actively turning off the switching power supply control chip after the power supply RS is turned off through the triode, so that independent power supply is not needed, and the problem of long shutdown time can be avoided.
Description
Technical Field
The utility model belongs to the technical field of servo driver switches, and particularly relates to a power-down self-turn-off circuit of a servo driver switching power supply.
Background
The servo driver needs to use a switching power supply, and part of servo driver circuits enable the switching power supply to take power from a main loop of the servo, so that independent power supply is not needed.
However, with application of the technology, we find a problem that a switching power supply for taking power from a main servo loop generally has a problem of long shutdown time, and each shutdown time is as long as tens of seconds, which affects the actual use experience of the servo. Therefore, the circuit structure is improved, so that the switching power supply does not need to independently supply power, and the problem of long shutdown time can be avoided.
Disclosure of Invention
In order to achieve the above purpose, the present utility model adopts the following technical scheme:
a power-down self-turn-off circuit of a switching power supply of a servo driver is characterized in that a switching power supply control chip is connected with a power supply RS of the servo driver through a turn-off circuit, the turn-off circuit is from the power supply RS to the switching power supply control chip and sequentially comprises a power on-off detection circuit and a switching circuit, when the power on-off detection circuit detects that the power supply RS supplies power normally, the switching circuit is turned off, and when the power on-off detection circuit detects that the power supply RS is turned off, the switching circuit is turned on, and a COMP pin of the switching power supply control chip is pulled down to turn off the switching power supply.
In the power-down self-turn-off circuit of the servo driver switching power supply, the switching circuit comprises a PNP triode Q32, a base electrode of the PNP triode Q32 is connected with the on-off detection circuit, an emitter electrode of the PNP triode Q32 is connected with the switching power supply control chip, and a collector electrode of the PNP triode Q32 is connected with a ground terminal;
when the on-off detection circuit detects that the power supply RS supplies power normally, the PNP triode Q32 is turned off, and the switching power supply control chip works normally;
when the on-off detection circuit detects that the power supply RS is turned off, the PNP triode Q32 is turned on, the COMP pin of the switch power supply control chip is pulled down, and the switch power supply control chip turns off the power supply.
In the power-down self-turn-off circuit of the servo driver switching power supply, the emitter of the PNP triode Q32 is connected to the COMP pin of the switching power supply control chip, and the COMP pin is connected to the VFB pin of the switching power supply control chip through the resistor R286 and the capacitor C233.
In the power-down self-turn-off circuit of the servo driver switching power supply, the switching power supply control chip adopts a UC2844 type chip.
In the power-off self-turn-off circuit of the servo driver switching power supply, the on-off detection circuit comprises resistors R488 and R487, capacitors C393 and C394, two ends of the resistor R487 are respectively connected with an R end and an S end of a power supply RS, one end of the resistor R488 is connected with one end of the resistor R487, the other end of the resistor R488 is connected with one end of the capacitor C393, the other end of the capacitor C393 is connected with one end of the resistor R487 far away from the R488, the capacitor C394 is connected with the capacitor C393 in parallel, the common end of the resistor R488 and the capacitors C393 and C394 is connected with a base electrode of the PNP triode Q32, and one end of the resistor R487 far away from the resistor R488 is connected with a collector electrode of the PNP triode Q32 together at a ground end.
In the power-down self-turn-off circuit of the servo driver switching power supply, when the power supply RS supplies power normally, the base voltage of the PNP triode Q32 is larger than the emitter voltage, the PNP triode Q32 is turned off, and the switching power supply control chip works normally;
when the power supply RS is turned off, the C393 and C394 discharge through the resistors R487 and R488, and when the base voltage of the PNP triode Q32 is reduced to the voltage threshold, the PNP triode Q32 is turned on, the COMP pin of the switch power supply control chip is pulled down, and the switch power supply control chip turns off the power supply.
In the power-down self-turn-off circuit of the servo driver switching power supply, the capacitance value of the capacitor C393 is 1-100uf, and the capacitance value of the capacitor C394 is 1-100uf;
the resistance value of the resistor R488 is 15-51K ohms, and the resistance value of the resistor R487 is 5-51K ohms.
In the power-down self-turn-off circuit of the servo driver switching power supply, the resistance value of the resistor R488 is 51K ohms, and the resistance value of the resistor R487 is 15K ohms;
the capacitance of the capacitor C393 is 10uf and the capacitance of the capacitor C394 is 10uf.
In the power-down self-turn-off circuit of the servo driver switching power supply, resistors R481, R482, R483 and R484 are further connected between the power-on/off detection circuit and the power supply RS, the resistors R481 and R482 are sequentially connected between the R end of the power supply RS and the power-on/off detection circuit in series, and the resistors R483 and R484 are sequentially connected between the S end of the power supply RS and the power-on/off detection circuit in series.
In the power-down self-turn-off circuit of the servo driver switching power supply, switching diodes D59 and D58 formed by two diode opposite directions are arranged between the on-off detection circuit and the resistors R482 and R484;
the 3 rd end of the switching diode D59 is connected to the resistor R482, the 2 nd end is connected to the common end of the resistors R488 and R487 and the 2 nd end of the switching diode D58, and the 1 st end is connected to the ground;
the 3 rd end of the switching diode D58 is connected to the resistor R484, and the 1 st end is connected to the ground;
a parallel circuit including a diode D60 and a resistor R486 is connected in parallel to the resistor R487.
The utility model has the advantages that: the scheme provides a power-down self-turn-off circuit, realizes the power-off detection effect on the power supply RS through the detection circuit, and realizes the effect of actively turning off the switching power supply control chip after the power supply RS is turned off through the triode, so that independent power supply is not needed, and the problem of long shutdown time can be avoided.
Drawings
FIG. 1 is a block diagram of a power down self-turn-off circuit of a servo driver switching power supply of the present utility model;
FIG. 2 is a block diagram of a switching power supply control chip and its peripheral circuits of the power-down self-turn-off circuit of the servo driver switching power supply of the present utility model.
Detailed Description
The utility model will be described in further detail with reference to the drawings and the detailed description.
As shown in fig. 1 and fig. 2, the power-down self-turn-off circuit of the switch power supply of the servo driver is shown, the switch power supply control chip is connected with the power supply RS of the servo driver through the turn-off circuit, the turn-off circuit self-supplies the power supply RS to the switch power supply control chip, the turn-off circuit sequentially comprises a power-on/off detection circuit and a switch circuit, when the power-on/off detection circuit detects that the power supply RS is powered normally, the switch circuit is turned off, and when the power-on/off detection circuit detects that the power supply RS is turned off, the switch circuit is turned on, and the COMP pin of the switch power supply control chip is pulled down so as to turn off the switch power supply.
Specifically, the switching circuit includes a PNP transistor Q32, a base of the PNP transistor Q32 is connected to the on-off detection circuit, an emitter of the PNP transistor Q32 is connected to a COMP pin of the switching power supply control chip, and a collector of the PNP transistor Q32 is connected to a ground terminal. And as shown in fig. 2, COMP pin is connected to VFB pin of the switching power supply control chip through resistor R286 with resistance value of 2K ohms and capacitor C233 with capacitance value of 0.1 uf.
When the on-off detection circuit detects that the power supply RS supplies power normally, the PNP triode Q32 is turned off, and the switching power supply control chip works normally;
when the on-off detection circuit detects that the power supply RS is turned off, the PNP triode Q32 is turned on, the COMP pin of the switch power supply control chip is pulled down, and the switch power supply control chip turns off the power supply.
Specifically, the on-off detection circuit comprises resistors R488 and R487, capacitors C393 and C394, wherein two ends of the resistor R487 are respectively connected with an R end and an S end of a power supply RS, one end of the resistor R488 is connected with one end of the resistor R487, the other end of the resistor R488 is connected with one end of the capacitor C393, the other end of the capacitor C393 is connected with one end, far away from the R488, of the resistor R488, the common end of the capacitor C393 and the capacitor C394 is connected with the base electrode of the PNP triode Q32, and one end, far away from the resistor R488, of the resistor R487 is connected with the collector electrode of the PNP triode Q32 together at the ground end.
In this embodiment, the capacitance of the capacitor C393 is preferably 10uf, the capacitance of the capacitor C394 is preferably 10uf, the resistance of the resistor R488 is preferably 51K ohms, and the resistance of the resistor R487 is preferably 15K ohms.
Further, resistors R481, R482, R483, and R484 are further connected between the power supply RS and the power on/off detection circuit, and in this embodiment, the values of the resistors R481, R482, R483, and R484 are all 100K ohms, the resistors R481 and R482 are sequentially connected in series between the R end of the power supply RS and the power on/off detection circuit, and the resistors R483 and R484 are sequentially connected in series between the S end of the power supply RS and the power on/off detection circuit.
Further, switching diodes D59 and D58 formed by two diode opposite directions are arranged between the on-off detection circuit and the resistors R482 and R484; the 3 rd end of the switching diode D59 is connected to the resistor R482, the 2 nd end is connected to the common end of the resistors R488 and R487 and the 2 nd end of the switching diode D58, and the 1 st end is connected to the ground; the 3 rd end of the switching diode D58 is connected to the resistor R484, and the 1 st end is connected to the ground; resistor R487 is further connected in parallel with a parallel circuit of diode D60 and resistor R486, wherein resistor R486 takes the value of 3K ohms here.
Preferably, the switching power supply control chip adopts a UC2844 model chip. Pin number 1 COMP of the UC2844 chip is the output of the internal error amplifier and can be used as the error amplifier compensation pin to which an external compensation element is connected to modify the error amplifier output. The error amplifier has current limit inside, so the user can control the zero duty cycle by externally forcing COMP to group, so the switching power supply can be turned off by pulling down the COMP pin; the pin 2 VFB is an input end of feedback voltage and is also an inverted input end of an error amplifier of the chip; the No. 3 pin ISENSE is an input end of current feedback and is also a normal phase input end of a current detection comparator in the chip, and the pulse width of PWM waves is adjusted according to the magnitude of the current feedback quantity, so that the stabilizing effect of output voltage is achieved; the pin number 4 RT/CT is an input end of an external oscillating circuit and can be used for determining the oscillating frequency of the UC2844 chip, and meanwhile, the oscillating frequency is 2 times of the frequency of the PWM; pin 5 is grounded; pin No. 6 OUT is the output of PWM wave; the pin 7 VCC is a power supply of the UC2844 chip and is used for inputting direct current 12-20V; pin 8 VREF is the 5V reference on the UC2844 chip itself, which is compared to the peripheral circuitry. In addition, as shown in FIG. 2, RT/CT, ISENSE, VFB and COMP are connected to VREF through respective resistors, capacitors or diodes, respectively.
The working principle of the power-down self-turn-off circuit of the servo driver switching power supply provided by the embodiment is as follows: the circuit can actively turn off the power control chip after the power supply RS is turned off, and the base electrode of the PNP triode Q32, namely the 1-pin voltage is higher than the emitter electrode, namely the 2-pin voltage, is normally electrified, and the Q32 is turned off, so that the switching power control chip U54 works normally. When the power supply RS is turned off, C393, C394 discharges through R487 and R488, and when the voltage of pin 1 of Q32 drops to about 1V, Q32 turns on, pulling pin 1 of U54 low, turning off the switching power supply. When the switch-off time is put into use, the capacitance values of C393 and C394 and the resistance values of R487 and R488 can be adjusted appropriately.
The specific embodiments described herein are offered by way of example only to illustrate the spirit of the utility model. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the utility model or exceeding the scope of the utility model as defined in the accompanying claims.
Although terms of a switching power supply control chip, a turn-off circuit, a servo driver, a power supply RS, an on-off detection circuit, a switching circuit, etc. are used more herein, the possibility of using other terms is not excluded. These terms are used merely for convenience in describing and explaining the nature of the utility model; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present utility model.
Claims (10)
1. A power-down self-turn-off circuit of a switching power supply of a servo driver is characterized in that a switching power supply control chip is connected with a power supply RS of the servo driver through a turn-off circuit, the turn-off circuit is from the power supply RS to the switching power supply control chip and sequentially comprises a power-on/off detection circuit and a switching circuit, when the power-on/off detection circuit detects that the power supply RS is powered normally, the switching circuit is turned off, the switching power supply control chip works normally, and when the power-on/off detection circuit detects that the power supply RS is turned off, the switching circuit is turned on, and a COMP pin of the switching power supply control chip is pulled down so as to turn off the switching power supply.
2. The self-turn-off circuit of a switching power supply of a servo driver according to claim 1, wherein the switching circuit comprises a PNP transistor Q32, a base electrode of the PNP transistor Q32 is connected to the on-off detection circuit, an emitter electrode is connected to the switching power supply control chip, and a collector electrode is connected to a ground terminal;
when the on-off detection circuit detects that the power supply RS supplies power normally, the PNP triode Q32 is turned off, and the switching power supply control chip works normally;
when the on-off detection circuit detects that the power supply RS is turned off, the PNP triode Q32 is turned on, the COMP pin of the switch power supply control chip is pulled down, and the switch power supply control chip turns off the power supply.
3. The self-turn-off circuit of the servo driver switching power supply according to claim 2, wherein the emitter of the PNP transistor Q32 is connected to the COMP pin of the switching power supply control chip, and the COMP pin is connected to the VFB pin of the switching power supply control chip through the resistor R286 and the capacitor C233.
4. The power-down self-turn-off circuit of a servo driver switching power supply according to claim 3, wherein said switching power supply control chip is a UC2844 model chip.
5. The self-turn-off circuit of claim 4, wherein the on-off detection circuit comprises resistors R488 and R487, capacitors C393 and C394, two ends of the resistor R487 are respectively connected to an R end and an S end of the power supply RS, one end of the resistor R488 is connected to one end of the resistor R487, the other end is connected to one end of the capacitor C393, the other end of the capacitor C393 is connected to one end of the resistor R487 far from the R488, the capacitor C394 is connected in parallel with the capacitor C393, a common end of the resistor R488 and the capacitors C393 and C394 is connected to a base electrode of the PNP triode Q32, and one end of the resistor R487 far from the resistor R488 is connected to a ground end together with a collector electrode of the PNP triode Q32.
6. The self-turn-off circuit of a switching power supply of a servo driver according to claim 5, wherein when the power supply RS supplies power normally, the base voltage of the PNP transistor Q32 is greater than the emitter voltage, the PNP transistor Q32 is turned off, and the switching power supply control chip operates normally;
when the power supply RS is turned off, the C393 and C394 discharge through the resistors R487 and R488, and when the base voltage of the PNP triode Q32 is reduced to the voltage threshold, the PNP triode Q32 is turned on, the COMP pin of the switch power supply control chip is pulled down, and the switch power supply control chip turns off the power supply.
7. The self-turn-off circuit of a servo driver switching power supply as claimed in claim 6, wherein the capacitance of the capacitor C393 is 1-100uf, and the capacitance of the capacitor C394 is 1-100uf;
the resistance value of the resistor R488 is 15-51K ohms, and the resistance value of the resistor R487 is 5-51K ohms.
8. The self-turn-off circuit of a servo driver switching power supply according to claim 7, wherein the resistance of the resistor R488 is 51K ohms and the resistance of the resistor R487 is 15K ohms;
the capacitance of the capacitor C393 is 10uf and the capacitance of the capacitor C394 is 10uf.
9. The self-turn-off circuit of a switching power supply of a servo driver according to claim 6, wherein resistors R481, R482, R483 and R484 are further connected between the on-off detection circuit and the power supply RS, the resistors R481 and R482 are sequentially connected in series between the R end of the power supply RS and the on-off detection circuit, and the resistors R483 and R484 are sequentially connected in series between the S end of the power supply RS and the on-off detection circuit.
10. The self-turn-off circuit for power failure of servo driver switching power supply according to claim 9, wherein a switching diode D59, D58 composed of two diode pairs is further provided between the on-off detection circuit and the resistors R482, R484;
the 3 rd end of the switching diode D59 is connected to the resistor R482, the 2 nd end is connected to the common end of the resistors R488 and R487 and the 2 nd end of the switching diode D58, and the 1 st end is connected to the ground;
the 3 rd end of the switching diode D58 is connected to the resistor R484, and the 1 st end is connected to the ground;
a parallel circuit including a diode D60 and a resistor R486 is connected in parallel to the resistor R487.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222562758.7U CN219041386U (en) | 2022-09-27 | 2022-09-27 | Power-down self-turn-off circuit of servo driver switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222562758.7U CN219041386U (en) | 2022-09-27 | 2022-09-27 | Power-down self-turn-off circuit of servo driver switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219041386U true CN219041386U (en) | 2023-05-16 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222562758.7U Active CN219041386U (en) | 2022-09-27 | 2022-09-27 | Power-down self-turn-off circuit of servo driver switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219041386U (en) |
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2022
- 2022-09-27 CN CN202222562758.7U patent/CN219041386U/en active Active
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