CN215817494U - Bus overcurrent turn-off circuit - Google Patents
Bus overcurrent turn-off circuit Download PDFInfo
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- CN215817494U CN215817494U CN202121613272.0U CN202121613272U CN215817494U CN 215817494 U CN215817494 U CN 215817494U CN 202121613272 U CN202121613272 U CN 202121613272U CN 215817494 U CN215817494 U CN 215817494U
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Abstract
The utility model discloses a bus overcurrent turn-off circuit, which belongs to the field of integrated circuits and comprises a voltage signal comparison circuit and a driving signal turn-off circuit; the voltage signal comparison circuit sets an overcurrent protection voltage value to avoid burning out components and a motor due to overlarge current; the drive signal shutoff circuit shuts off the drive signal, and the circuit is protected. According to the utility model, the bus overcurrent turn-off circuit is built by adopting the discrete device, so that the cost is lower, and the turn-off time of the PWM driving signal can be reduced; the limit value of the overcurrent protection can be adjusted by adjusting the adjustable resistor by adopting a bus overcurrent turn-off circuit.
Description
Technical Field
The utility model relates to the technical field of integrated circuits, in particular to a bus overcurrent turn-off circuit.
Background
The motor is driven, the operational amplifier is generally used in the industry to collect current and convert the current into a voltage signal, the voltage signal is compared with the reference voltage of the comparator and then output a signal to the singlechip, and the singlechip turns off the driving signal; this approach is expensive and has a time delay.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a bus overcurrent turn-off circuit, which aims to solve the problems that the existing overcurrent turn-off circuit is high in cost and has time delay.
In order to solve the above technical problem, the present invention provides a bus overcurrent turn-off circuit, including:
the voltage signal comparison circuit sets an overcurrent protection voltage value to avoid burning out components and a motor due to overlarge current;
the drive signal shutoff circuit, shutoff drive signal, protection circuit safety.
Optionally, the voltage signal comparison circuit includes a reference voltage generation circuit and a comparator U1B;
the reference voltage generating circuit generates a reference voltage which is input to one end of the comparator U1B; the other end of the comparator U1B inputs a voltage ISENSE _ C converted after sampling current; the output end of the comparator U1B is connected with the driving signal turn-off circuit.
Optionally, the reference voltage generating circuit includes an adjustable resistor IR1 connected between the voltage of 5V and ground GND; the reference voltage generated by dividing the voltage of 5V by the adjustable resistor IR1 is input to the comparator U1B through the filter capacitor C14.
Optionally, the driving signal turn-off circuit includes resistors R8, R9, R11, R12, R22, a diode D5, a transistor Q3, a transistor Q7, and a capacitor C15;
the triode Q7 and the resistor R9 form a hardware turn-off circuit for pulling down the driving signal, the base electrode of the triode Q7 is connected with the first end of the resistor R9, the collector electrode is connected with the base electrode of the triode Q3, and the emitter electrode is grounded; the second end of the resistor R9 is connected with the output end of the comparator U1B;
the base electrode of the triode Q3 is connected with the negative electrode of the diode D5, the collector electrode is simultaneously connected with the first end of the resistor R11 and the first end of the resistor R12, and the emitting electrode is grounded; the anode of the diode D5 is connected with the driving signal PWM through a resistor R8;
the base of the triode Q5 is connected with the second end of the resistor R12, the collector is connected with the IGBT _1 through the resistor R22, the emitter is simultaneously connected with the second end of the resistor R11 and the first end of the capacitor C15, and the second end of the capacitor C15 is grounded.
Optionally, the output end of the comparator U1B is further connected to a resistor R16.
The bus overcurrent turn-off circuit provided by the utility model comprises a voltage signal comparison circuit and a driving signal turn-off circuit; the voltage signal comparison circuit sets an overcurrent protection voltage value to avoid burning out components and a motor due to overlarge current; the drive signal shutoff circuit shuts off the drive signal, and the circuit is protected.
The utility model has the following beneficial effects:
(1) the bus overcurrent turn-off circuit is built by adopting a discrete device, so that the cost is low, and the turn-off time of the PWM driving signal can be reduced;
(2) the limit value of the overcurrent protection can be adjusted by adjusting the adjustable resistor by adopting a bus overcurrent turn-off circuit.
Drawings
FIG. 1 is a schematic diagram of a bus overcurrent shutdown circuit provided by the present invention;
fig. 2 is a schematic structural diagram of a bus overcurrent shutdown circuit provided by the utility model.
Detailed Description
The following provides a bus overcurrent shutdown circuit according to the present invention with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.
Example one
The utility model provides a bus overcurrent turn-off circuit, the block diagram of which is shown in figure 1, and the bus overcurrent turn-off circuit comprises a voltage signal comparison circuit 1 and a driving signal turn-off circuit 2; the voltage signal comparison circuit 1 sets an overcurrent protection voltage value to avoid burning out components and a motor due to overlarge current; the drive signal shutoff circuit 2 shuts off the drive signal, and the circuit is protected.
As shown in fig. 2, which is a schematic circuit structure diagram of a bus overcurrent shutdown circuit, the voltage signal comparison circuit 1 includes a reference voltage generation circuit 11 and a comparator U1B; the reference voltage generating circuit 11 generates a reference voltage, and inputs the reference voltage to one end (i.e. pin 6) of the comparator U1B; the other end (namely a pin 5) of the comparator U1B inputs a voltage ISENSE _ C converted after sampling current; the output end (namely 7 pins) of the comparator U1B is connected with the driving signal shutdown circuit 2. The reference voltage generating circuit 11 comprises an adjustable resistor IR1 connected between a voltage of 5V and ground GND; the reference voltage generated after the voltage of 5V is divided by the adjustable resistor IR1 is input to the comparator U1B through the filter capacitor C14, and the output end of the comparator U1B is also connected with a resistor R16.
The driving signal turn-off circuit 2 comprises resistors R8, R9, R11, R12, R22, a diode D5, triodes Q3 and Q7 and a capacitor C15; the triode Q7 and the resistor R9 form a hardware turn-off circuit 21 for pulling down the driving signal, the base electrode of the triode Q7 is connected with the first end of the resistor R9, the collector electrode is connected with the base electrode of the triode Q3, and the emitter electrode is grounded; the second end of the resistor R9 is connected with the output end of the comparator U1B; the base electrode of the triode Q3 is connected with the negative electrode of the diode D5, the collector electrode is simultaneously connected with the first end of the resistor R11 and the first end of the resistor R12, and the emitting electrode is grounded; the anode of the diode D5 is connected with the driving signal PWM through a resistor R8; the base of the triode Q5 is connected with the second end of the resistor R12, the collector is connected with the IGBT _1 through the resistor R22, the emitter is simultaneously connected with the second end of the resistor R11 and the first end of the capacitor C15, and the second end of the capacitor C15 is grounded.
The working principle of the bus overcurrent turn-off circuit is as follows:
the adjustable resistor IR1 is adjusted to a set value, the reference voltage of 5V voltage after being divided by the adjustable resistor IR1 is input to pin 6 of the comparator U1B through the filter capacitor C14, and the voltage ISENSE _ C converted after sampling the current is input to pin 5 of the comparator U1B; when the sampled voltage ISENSE _ C is smaller than the reference voltage, the pin 7 at the output end of the comparator U1B outputs a low level, no current exists in the resistor R9, the base of the transistor Q7 is a low level, the transistor Q7 is in an off state, the driving signal PWM is not limited, when the driving signal PWM is a high level, the base voltage of the transistor Q3 is greater than 0.7V, the transistor Q3 is in an on state, the collector of the transistor Q3 is a low level, no current exists in the resistor R12, the base voltage of the transistor Q5 is a low level, the emitter voltage of the transistor Q5 is 12V, at this time, the transistor Q5 is in an on state, and the voltage 12V is output to the IGBT _1 to be turned on. When the PWM is low, there is no current in the resistor R8, the base of the transistor Q3 is low, the transistor Q3 is off, the collector of the transistor Q3 is high, the base and the emitter of the transistor Q5 are both high, the transistor Q5 is off, and the voltage 12V cannot be output to the IGBT _1, so that it is turned on.
When the sampled voltage ISENSE _ C is greater than the reference voltage, the pin 7 at the output end of the comparator U1B outputs a high level, the triode Q7 is switched on, the base electrode of the triode Q3 is pulled to a low level, at the moment, the triode Q3 is in a turn-off state no matter whether PWM is the high level or not, the triode Q5 is also in a turn-off state, 12V voltage cannot be output to the IGBT _1, the IGBT _1 cannot be switched on, and therefore bus overcurrent protection and circuit turn-off are achieved.
The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.
Claims (4)
1. A bus overcurrent turn-off circuit, comprising:
the voltage signal comparison circuit sets an overcurrent protection voltage value to avoid burning out components and a motor due to overlarge current;
the driving signal shutoff circuit shuts off the driving signal, so that the safety of the circuit is protected;
the voltage signal comparison circuit comprises a reference voltage generation circuit and a comparator U1B; the reference voltage generating circuit generates a reference voltage which is input to one end of the comparator U1B; the other end of the comparator U1B inputs a voltage ISENSE _ C converted after sampling current; the output end of the comparator U1B is connected with the driving signal turn-off circuit.
2. The bus overcurrent shutdown circuit of claim 1, wherein the reference voltage generation circuit comprises an adjustable resistor IR1 connected between a voltage of 5V and ground GND; the reference voltage generated by dividing the voltage of 5V by the adjustable resistor IR1 is input to the comparator U1B through the filter capacitor C14.
3. The bus overcurrent shutdown circuit as claimed in claim 1, wherein the drive signal shutdown circuit comprises resistors R8, R9, R11, R12, R22, a diode D5, a triode Q3, Q7 and a capacitor C15;
the triode Q7 and the resistor R9 form a hardware turn-off circuit for pulling down the driving signal, the base electrode of the triode Q7 is connected with the first end of the resistor R9, the collector electrode is connected with the base electrode of the triode Q3, and the emitter electrode is grounded; the second end of the resistor R9 is connected with the output end of the comparator U1B;
the base electrode of the triode Q3 is connected with the negative electrode of the diode D5, the collector electrode is simultaneously connected with the first end of the resistor R11 and the first end of the resistor R12, and the emitting electrode is grounded; the anode of the diode D5 is connected with the driving signal PWM through a resistor R8;
the base of the triode Q5 is connected with the second end of the resistor R12, the collector is connected with the IGBT _1 through the resistor R22, the emitter is simultaneously connected with the second end of the resistor R11 and the first end of the capacitor C15, and the second end of the capacitor C15 is grounded.
4. The bus overcurrent shutdown circuit as claimed in claim 1, wherein a resistor R16 is further connected to the output of the comparator U1B.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121613272.0U CN215817494U (en) | 2021-07-15 | 2021-07-15 | Bus overcurrent turn-off circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121613272.0U CN215817494U (en) | 2021-07-15 | 2021-07-15 | Bus overcurrent turn-off circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215817494U true CN215817494U (en) | 2022-02-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121613272.0U Active CN215817494U (en) | 2021-07-15 | 2021-07-15 | Bus overcurrent turn-off circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215817494U (en) |
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2021
- 2021-07-15 CN CN202121613272.0U patent/CN215817494U/en active Active
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