Output circuit of laser radar
By introducing a control module, multiple switching modules, and a comparison module into the lidar output circuit, overcurrent and overvoltage detection is achieved, solving the problems of slow fuse response and easy transistor burnout, thus improving the safety and reliability of the circuit.
Patent Information
- Application Number
- CN202422945598.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2034-12-02
AI Technical Summary
In existing PNP output circuits for lidar, the fuse response time is slow, the current limiting effect is poor, the transistor is prone to burning out, and the turn-on voltage of the TVS diode fluctuates greatly, resulting in insufficient safety.
The system employs a combination of a control module, a first switch module, a second switch module, a third switch module, a comparison module, and a current control module. Through overcurrent detection and overvoltage detection functions, it protects the switching transistors and prevents them from burning out.
It effectively protects the switching transistor, improves the safety and reliability of the LiDAR PNP output circuit, and reduces the risk of damage to the switching transistor.
Smart Images
Figure CN223815434U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit technology, and in particular to an output circuit for a lidar. Background Technology
[0002] Obstacle avoidance lidar has been widely used in safety protection, AGV (Automated Guided Vehicle) guideways, and other fields. The core technology of obstacle avoidance lidar is its ability to switch between outputting 24V or 0V via a PNP port when an object is detected within the protected area. Upon detecting this level switch at the PNP port, the receiver either stops operating or activates an alarm light, thus achieving the purpose of safety protection.
[0003] Currently, commonly used PNP protection circuits mainly include MOSFETs, transistors, TVS diodes, fuses, and resistors. The fuse provides current limiting protection, the TVS diode provides overvoltage protection, and the transistor switches between 24V and 0V levels. A specific circuit is shown below. Figure One The fuse response time is relatively slow, sometimes the transistor Q2 burns out before the fuse activates, causing the PNP transistor to remain open. The fuse consistency is poor, with a difference of 150mA~200mA between the start-up protection current and the holding current, resulting in poor current limiting performance. This also makes the downstream transistor Q2 prone to burnout, and the TVS diode's turn-on voltage fluctuates significantly. Figure 1 The selected TVS diode has a nominal voltage of 30V, but its actual turn-on voltage is between 34V and 36V. A surge voltage between 30V and 34V can easily burn out the transistor Q2 in the subsequent stage. How to improve the safety of the PNP output circuit of the lidar is an urgent problem to be solved. Utility Model Content
[0004] To address the aforementioned technical problems, this utility model provides an output circuit for a lidar.
[0005] In a first aspect, this utility model provides an output circuit for a lidar, the output circuit of which includes at least: a control module, a first switch module, a second switch module, a third switch module, a comparison module, and a current control module, wherein:
[0006] The control module is connected to the second switch module through the first switch module, the second switch module is connected to the third switch module, and the second switch module is also connected to the current control module and the comparison module.
[0007] Optionally, the control pin of the control module is connected to the first pin of the first switch module, the second pin of the first switch module is connected to ground, and the third pin of the first switch module is connected to the first pin of the second switch module.
[0008] Optionally, the third pin of the second switch module is connected with a first resistor, and the second pin of the second switch module is connected with the current control module.
[0009] Optionally, the second pin of the second switch module is connected with the third pin of the comparison module, and the fourth pin of the comparison module is connected with a reference voltage 2.5V.
[0010] Optionally, the first pin of the comparison module is connected with a voltage detection pin.
[0011] Optionally, the third pin of the second switch module is connected with the first pin of the third switch module, and the third pin of the third switch module is connected with a current detection pin.
[0012] Optionally, the control module is a single-chip microcomputer.
[0013] Optionally, the first switch module is an NPN triode, and the second switch module and the third switch module are PNP triodes.
[0014] Optionally, the current control module is a fuse.
[0015] Optionally, the comparison module is a TS391ILT chip.
[0016] The output circuit of the laser radar provided by the utility model at least comprises: a control module, a first switch module, a second switch module, a third switch module, a comparison module and a current control module, wherein: the control module is connected with the second switch module through the first switch module, the second switch module is connected with the third switch module, and the second switch module is also connected with the current control module and the comparison module, by adopting the overcurrent detection function and the overvoltage detection function, the switch tube can be effectively protected, and the switch tube is prevented from being burnt out. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is an output circuit schematic view of a laser radar of the prior art;
[0018] Figure 2 It is an output circuit schematic view of a laser radar provided by the utility model embodiment;
[0019] Figure 3 It is a structural schematic view of another output circuit of a laser radar provided by the utility model embodiment. DETAILED DESCRIPTION
[0020] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.
[0021] Please refer to Figure 2 The present application provides a circuit schematic diagram of an output circuit of a laser radar, which comprises a control module, a first switch module Q1, a second switch module Q2, a third switch module Q3, a comparison module U1 and a current control module F1, wherein:
[0022] The control module is connected with the first switch module and the second switch module, the second switch module is connected with the third switch module, and the second switch module is also connected with the current control module and the comparison module.
[0023] Optionally, a control pin of the control module is connected with a first pin of the first switch module, a second pin of the first switch module is connected with the ground, and a third pin of the first switch module is connected with a first pin of the second switch module.
[0024] Optionally, a third pin of the second switch module is connected with a first resistor, and a second pin of the second switch module is connected with the current control module.
[0025] Optionally, a second pin of the second switch module is connected with a third pin of the comparison module, and a fourth pin of the comparison module is connected with a 2.5V reference voltage.
[0026] Optionally, a first pin of the comparison module is connected with a voltage detection pin.
[0027] Optionally, a third pin of the second switch module is connected with a first pin of the third switch module, and a third pin of the third switch module is connected with a current detection pin.
[0028] Optionally, the control module is a single-chip microcomputer.
[0029] Optionally, the first switch module is an NPN triode, and the second switch module and the third switch module are PNP triodes.
[0030] Optionally, the current control module is a fuse.
[0031] Optionally, the comparison module is a TS391ILT chip.
[0032] As shown in Figure 2 and Figure 3 , the working principle of the above-mentioned output circuit of the laser radar is that:
[0033] 1. Controller (control module) controls MCU_CTRL signal to 3.3V, Q1 is turned on, the base voltage of Q2 is changed from 24V to low, Q2 is turned on, PNP_OUT outputs 24V, and the current flows in the direction of 24V->R1->Q2->F1->external load;
[0034] 2. When the current is large, the resettable fuse F1 is triggered, and F1 turns off the PNP output loop;
[0035] 3. When the load end surge is large, TVS1 or TVS2 is started, and the current flows away from TVS1 or TVS2, and does not flow to Q2;
[0036] 4. When the current is large, the resettable fuse F1 is not triggered, or F1 has not reacted, and the voltage drop between the two ends of R1 reaches QP1 after the start, Q3 is started instantaneously, the controller detects that the CURRENT_CHECK signal is 0V, and then the MCU_CTRL signal is low, Q1 is turned off, the emitter level and the base voltage of Q2 are equal after Q1 is turned off, and Q2 is also turned off. The actual overcurrent self-checking circuit processing is about 5ms, which is much lower than the time required when Q2 is burned out, and the risk of burning out Q2 can be effectively protected;
[0037] 5. When the voltage at Q2 is higher than 30V, the voltage at the negative end of the comparator U1 is higher than the voltage at the positive end of the comparator, U1 outputs 0V, when the controller detects that VOL_CHECK is 0V, MCU_CTRL is 0V, Q1 is turned off, and Q2 is further turned off. The actual overcurrent self-checking circuit processing is about 5ms, which is much lower than the time required when Q2 is burned out, and the risk of burning out Q2 can be effectively protected.
[0038] The output circuit of the laser radar comprises a control module, a first switch module, a second switch module, a third switch module, a comparison module and a current control module, wherein the control module is connected with the second switch module through the first switch module, the second switch module is connected with the third switch module, the second switch module is further connected with the current control module and the comparison module, and by adopting the overcurrent detection function and the overvoltage detection function, the switch tube can be effectively protected, and the switch tube is prevented from being burned out.
[0039] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. An output circuit of a laser radar, characterized by comprising: The output circuit comprises at least a control module, a first switch module, a second switch module, a third switch module, a comparison module and a current control module, wherein: The control module is connected with the first switch module, the second switch module is connected with the third switch module, and the second switch module is also connected with the current control module and the comparison module.
2. The output circuit of the lidar according to claim 1, wherein, The control pin of the control module is connected with the first pin of the first switch module, the second pin of the first switch module is connected with the ground, and the third pin of the first switch module is connected with the first pin of the second switch module.
3. The output circuit of a lidar according to claim 2, wherein, The third pin of the second switch module is connected with a first resistor, and the second pin of the second switch module is connected with the current control module.
4. The output circuit of the laser radar according to claim 1, wherein The second pin of the second switch module is connected with the third pin of the comparison module, and the fourth pin of the comparison module is connected with a reference voltage 2.5V.
5. The output circuit of the lidar according to claim 4, wherein, The first pin of the comparison module is connected with a voltage detection pin.
6. The output circuit of the lidar according to claim 5, wherein, The third pin of the second switch module is connected with the first pin of the third switch module, and the third pin of the third switch module is connected with a current detection pin.
7. The output circuit of the lidar according to claim 1, wherein, The control module is a single-chip microcomputer.
8. The output circuit of the lidar according to claim 1, wherein, The first switch module is an NPN triode, and the second switch module and the third switch module are PNP triodes.
9. The output circuit of the lidar according to claim 1, wherein, The current control module is a fuse.
10. The output circuit of the lidar according to claim 1, wherein, The comparison module is a TS391ILT chip.