Dynamic control circuit with output detection function

Abstract

A dynamic control circuit with an output detection function belongs to the technical field of electronic circuits, one end of the dynamic control circuit is connected with an MCU controller, the other end of the dynamic control circuit is connected with a load, and the dynamic control circuit comprises a dynamic circuit, a read-back detection circuit and a static control circuit which are connected with the MCU controller. The dynamic circuit is connected with the MCU controller through a control signal IN1 and used for circuit dynamic safe output, and when the MCU controller has continuous high and low level dynamic signal output, the dynamic circuit is conducted to generate output; the static control circuit is connected with the MCU controller through a control signal IN2 and is used for rapidly cutting off output in an emergency state, and when the MCU controller judges that the output is cut off emergently, the static control circuit immediately turns off the dynamic control circuit; and the read-back detection circuit is connected with the MCU controller through Readback and is used for detecting the output state of the dynamic circuit. The dynamic control of the output circuit is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic circuits, and in particular relates to a dynamic control circuit with an output detection function. Background Art

[0002] With the rapid development of railways, the speed of trains is constantly increasing, and the requirements for railway products are getting higher and higher. The fail-safe principle should be strictly followed. For the output circuits involving safety in railway products, they must not only have high reliability, but also require that there should be no dangerous output in the fault state. MCU and other control chip technologies are relatively mature and have been widely used, but they cannot guarantee that the output is stable in a certain state in the fault state, which brings risks to the output circuit. Using dynamic control circuits is a way to solve this problem.

[0003] At present, there are two types of dynamic circuits: those isolated by transformers and those built with electronic components. The dynamic circuits isolated by transformers are large in size, have large losses, low efficiency and high cost. The dynamic circuits built with electronic components have the characteristics of small size and low losses, but the existing dynamic circuits have problems such as the readback detection circuit cannot directly reflect the output status, and there are also problems such as slow output shutdown time. Summary of the invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a dynamic control circuit with an output detection function to realize dynamic control of the output circuit. The output voltage is increased by a bootstrap circuit, and the circuit has a readback detection function to give early warning information for possible dangerous outputs. The output is quickly shut down by a static control circuit. The MCU control circuit is isolated from the dynamic control circuit.

[0005] In order to achieve the above object, the main technical solutions adopted by the present invention include: A dynamic control circuit with an output detection function, wherein one end of the dynamic control circuit is connected to an MCU controller, and the other end is connected to a load. The dynamic control circuit comprises a dynamic circuit connected to the MCU controller, a readback detection circuit, and a static control circuit. The dynamic circuit is connected to the MCU controller via a control signal IN1 and is used for circuit dynamic safety output. When the MCU controller has continuous high and low level dynamic signal outputs, the dynamic circuit is turned on to generate output. The static control circuit is connected to the MCU controller via a control signal IN2 and is used for quickly cutting off the output in an emergency state. When the MCU controller determines that the output is to be cut off urgently, the static control circuit immediately turns off the dynamic control circuit. The readback detection circuit is connected to the MCU controller via Readback and is used to detect the output state of the dynamic circuit.

[0006] Furthermore, the dynamic circuit includes a resistor R1 connected in series with IN1 of the MCU, the resistor R1 is connected to the input cathode of the photoelectric isolation device IC1, and the input anode of the photoelectric isolation device IC1 is connected to the power supply VCC; the output collector of the photoelectric isolation device IC1 is connected in series with the resistor R2 and then connected to the collector of the transistor BG1, and then connected to the power supply V+ after the resistor R4 is connected in series; the output collector of the photoelectric isolation device IC1 is connected to the anode of the diode D1 and the cathode of the diode D2, and the cathode of the diode D1 is connected to the base of the transistor BG1; the diode D 2 is connected to the base of the transistor BG2 after being connected to the resistor R3; the emitter of the transistor BG1 is connected to the emitter of the transistor BG2, and the emitters of the transistors BG1 and BG2 are connected in series with the capacitor C4 to the cathode of the Schottky diode D7 and the anode of the Schottky diode D6; the anode of the Schottky diode D7 is connected to one end of the capacitor C8 and the output terminal OUT-; the output emitter of the optoelectronic isolation device IC1 is connected to the collector of the transistor BG2, the cathode of the Schottky diode D6, the other end of the capacitor C8 and the power supply V-.

[0007] Furthermore, the static control circuit includes a resistor R5 connected in series with IN2 of the MCU, the resistor R5 is connected to the input cathode of the optoelectronic isolation device IC3, the input anode of the optoelectronic isolation device IC3 is connected to the power supply VCC; the output collector of the optoelectronic isolation device IC3 is connected to the input cathode of the optoelectronic isolation device IC2; the output emitter of the optoelectronic isolation device IC3 is connected to the anode of the diode D5 and the output terminal OUT+.

[0008] Furthermore, the readback detection circuit includes a photoelectric isolation device IC2, the Readback of the MCU is connected to the output collector of the photoelectric isolation device IC2, the output collector of the photoelectric isolation device IC2 is connected to the power supply VCC through a series resistor R6; the output emitter of the photoelectric isolation device IC2 is connected to the power supply ground GND; the input anode of the photoelectric isolation device IC2 is connected to the cathode of the diode D5 and the power supply V-; the input cathode of the photoelectric isolation device IC2 is connected to the output collector of the photoelectric isolation device IC3.

[0009] Furthermore, the dynamic circuit also includes capacitor C1, capacitor C2, diode D3, and diode D4. Capacitor C1 is connected to resistor R2 and the cathode of diode D4. The other end of capacitor C1 is connected to one end of capacitor C2 and the emitter of transistor BG1 and the emitter of transistor BG2. The other end of capacitor C2 is connected to the output emitter of photoelectric isolation device IC1 and the anode of diode D3. The anode of diode D4 is connected to resistor R4 and the collector of transistor BG1. The cathode of diode D3 is connected to the collector of transistor BG2, the cathode of Schottky diode D6, the other end of capacitor C8, and power supply V-.

[0010] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention improves the protection mechanism and readback detection circuit of the dynamic control circuit. A boost bootstrap circuit is added to the circuit, so that the output voltage meets the load usage requirements without increasing the working power supply voltage. By adding a static control circuit, two-level control of the output circuit is achieved, and time-sharing detection of the circuit is achieved through delayed opening, so that faults are discovered in time and the accumulation of circuit faults is avoided; the dynamic control circuit output is quickly shut down, and the safety and reliability of the circuit are increased. The present invention uses electronic components to construct a dynamic circuit, which realizes miniaturization of the circuit, low loss, convenient implementation, and better application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall connection of the dynamic control circuit of the present invention; Figure 2 is a schematic diagram of a dynamic control circuit of the present invention; Figure 3 is a dynamic circuit schematic diagram of the present invention; Figure 4 It is the readback detection and static control circuit diagram of the present invention; Figure 5 It is a voltage bootstrap circuit diagram of the present invention. DETAILED DESCRIPTION

[0012] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0013] The present invention provides a dynamic control circuit with output detection function, such as Figure 1 As shown, one end of the dynamic control circuit is connected to the MCU controller, and the other end is connected to the load. The dynamic control circuit includes a dynamic circuit connected to the MCU controller, a readback detection circuit, and a static control circuit. The dynamic circuit is connected to the MCU controller through a control signal IN1 for circuit dynamic safety output. IN1 is a dynamic signal used to drive the dynamic control circuit. When the MCU controller has continuous high and low level dynamic signal outputs, the dynamic circuit is turned on and generates output; the static control circuit is connected to the MCU controller through a control signal IN2 for rapid output cutoff in an emergency state. IN2 is a stable level signal used to drive the static control circuit. When the MCU controller determines that the output is cutoff in an emergency, the static control circuit immediately turns off the dynamic control circuit; the readback detection circuit is connected to the MCU controller through Readback to detect the output state of the dynamic circuit. OUT+ and OUT- are circuit outputs for driving the load. V+ and V- are working power supplies. The dynamic control circuit is isolated from the MCU control circuit by optoelectronic isolation devices IC1, IC2, and IC3.

[0014] Specifically, Figure 2-3 As shown, the dynamic circuit includes a resistor R1 connected in series with IN1 of the MCU, the resistor R1 is connected to the input cathode (pin 2) of the optoelectronic isolation device IC1, and the input anode (pin 1) of the optoelectronic isolation device IC1 is connected to the power supply VCC; the output collector (pin 4) of the optoelectronic isolation device IC1 is connected in series with the resistor R2 and then connected to the collector of the transistor BG1, and then connected to the power supply V+ after the resistor R4 is connected in series; the output collector (pin 4) of the optoelectronic isolation device IC1 is connected to the anode of the diode D1 and the cathode of the diode D2, and the cathode of the diode D1 is connected to the The base of the diode D2 is connected to the resistor R3 and then to the base of the transistor BG2; the emitter of the transistor BG1 is connected to the emitter of the transistor BG2, and the emitters of the transistors BG1 and BG2 are connected in series with the capacitor C4 to the cathode of the Schottky diode D7 and the anode of the Schottky diode D6; the anode of the Schottky diode D7 is connected to one end of the capacitor C8 and the output end OUT-; the output emitter of the optoelectronic isolation device IC1 is connected to the collector of the transistor BG2, the cathode of the Schottky diode D6, the other end of the capacitor C8 and the power supply V-.

[0015] Specifically, Figure 5 As shown, the dynamic circuit also includes capacitor C1, capacitor C2, diode D3, and diode D4. Capacitor C1, capacitor C2, diode D3, and diode D4 are added to the dynamic circuit of the present invention to realize voltage bootstrapping. Capacitor C1 is connected to the cathode of resistor R2 and diode D4, the other end of capacitor C1 is connected to one end of capacitor C2 and the emitter of transistor BG1 and the emitter of transistor BG2, and the other end of capacitor C2 is connected to the output emitter (pin 3) of photoelectric isolation device IC1 and the anode of diode D3. The anode of diode D4 is connected to resistor R4 and the collector of transistor BG1. The cathode of diode D3 is connected to the collector of transistor BG2, the cathode of Schottky diode D6, the other end of capacitor C8, and the power supply V-.

[0016] The dynamic circuit IN1 is connected to the MCU control pin, and the dynamic signal is input. After isolation by the optoelectronic isolation device IC1, the voltage state of point A is changed. By connecting D1 and D2 to the base of transistors BG1 (NPN) and BG2 (PNP), the on and off of transistors BG1 and BG2 are controlled. Only one transistor is turned on at the same time. The power supply V+ is connected to the power supply V- through R4, BG1 collector, BG1 emitter, BG2 collector, and BG2 emitter. R4 is used to prevent the power supply from short-circuiting after BG1 and BG2 short-circuit failure. When IN1 is high, the optoelectronic isolation device IC1 is blocked, and the power supply V+ passes through R4, D4, R2, and D1 to the base of BG1 (D2 is used for reverse blocking), and the voltage at point A is high, and transistor BG1 is turned on. At this time, the power supply V+ charges the capacitor C4 through R4 and BG1. When IN1 is at a low level, the optoelectronic isolation device IC1 is turned on, and the power supply V- passes through D3, IC1, D2, R3 to the base of BG2 (D1 is used for reverse blocking), and the voltage at point A is low, and the transistor BG2 is turned on. At this time, the capacitor C4 is discharged, and the potential of point B is approximately the same as that of V-. A voltage difference appears across C8, and the voltage of V- is higher than OUT-. When a continuous pulse signal is input to the IN1 end, the output ends OUT+ and OUT- form a stable output signal. When a stable high-level or low-level signal is input to the IN1 end, faults of transistors BG1 and BG2 will not cause erroneous output. R4 is used to prevent power supply short circuit caused by the breakdown of BG1 and BG2.

[0017] The bootstrap circuit is connected to the dynamic circuit, including diode D4 connected to capacitor C1, and connected to the collector and emitter of BG1, capacitor C2 connected to diode D3, and connected to the collector and emitter of BG2. The power supply V+ charges capacitor C1 through R4, D4, C1, C4, and D6. When BG1 is turned on, the voltage at point B is close to V+. Since the voltage across capacitor C1 will not change suddenly, the voltage at point C is raised and higher than V+. D4 is connected between C1 and power supply V+ to reversely cut off the voltage at point C. The power supply at point C passes through R2 and D1 to the base of BG1, maintaining BG1 in a saturated conduction state, thereby ensuring that a higher voltage is obtained across capacitor C4. When BG1 is turned on, capacitor C2 is charged at the same time. When IC1 is turned on, transistor BG2 is turned on, and the voltage at point B is close to V-. Since the voltage across capacitor C2 will not change suddenly, the voltage at point D is pulled down and is lower than V-. D3 is connected between C2 and power supply V- to reversely cut off the V- voltage to prevent the voltage at point D from being pulled up by V-. The power supply is connected to V- through the base of BG2, R3, D2, IC1, and D3, maintaining BG2 in a saturated conduction state, ensuring that the voltage across capacitor C8 is closer to the voltage across C4, and ensuring that the output can obtain a higher voltage value, thereby achieving voltage bootstrapping without increasing the working power supply voltage.

[0018] Specifically, Figure 4As shown, the static control circuit includes a resistor R5 connected in series with IN2 of the MCU, the resistor R5 is connected to the input cathode of the photoelectric isolation device IC3, and the input anode of the photoelectric isolation device IC3 is connected to the power supply VCC; the output collector of the photoelectric isolation device IC3 is connected to the input cathode of the photoelectric isolation device IC2; the output emitter of the photoelectric isolation device IC3 is connected to the anode of the diode D5 and the output terminal OUT+. The 4th pin of the static control circuit photoelectric isolation device IC3 is connected to the 2nd pin of the readback detection circuit IC2, and the 3rd pin is connected to OUT+. The 1st pin of IC3 is connected to VCC. . The 2nd pin of IC3 is connected to the IN2 pin of the MCU through R5. The MCU outputs a continuous low-level signal through the IN2 pin to turn on IC3, and outputs a continuous high-level signal to turn off IC3. The secondary control of the output circuit is realized. When an emergency situation requires rapid output shutdown, since the dynamic circuit adopts a capacitor charging and discharging circuit, the output cannot be shut down immediately, and the static control circuit is used to realize rapid output shutdown. The circuit realizes two-level control, dynamic control and static control, through IN1 and IN2. It adopts two-level time-sharing opening to realize time-sharing detection of the circuit, so as to find faults in time and avoid the accumulation of circuit faults.

[0019] Specifically, the readback detection circuit includes a photoelectric isolation device IC2, the Readback of the MCU is connected to the output collector of the photoelectric isolation device IC2, and the output collector of the photoelectric isolation device IC2 is connected to the power supply VCC through a series resistor R6; the output emitter of the photoelectric isolation device IC2 is connected to the power supply ground GND; the input anode of the photoelectric isolation device IC2 is connected to the cathode of the diode D5 and the power supply V-; the input cathode of the photoelectric isolation device IC2 is connected to the output collector of the photoelectric isolation device IC3. Pin 1 of the photoelectric isolation device IC2 of the readback detection circuit is connected to V-, and pin 2 is connected to pin 4 of the photoelectric isolation device IC3. Pin 3 of IC2 is connected to GND. The VCC power supply is connected to pin 4 of IC2 through R6, and is also connected to the Readback pin of the MCU. The MCU detects the circuit output state by reading the Readback pin state. If the circuit output state is inconsistent with the checkback state, the external output control signals IN1 and IN2 are cut off. Input and output signal isolation is achieved through the photoelectric isolation device IC2.

[0020] The circuit of the present invention realizes two-level control of dynamic control and static control through IN1 and IN2, and realizes time-sharing detection of the circuit by adopting a two-level time-sharing opening method, so as to find faults in time and avoid the accumulation of circuit faults. The circuit realizes isolation between the dynamic control circuit and the MCU control circuit through IC1, IC2 and IC3, so as to improve the anti-interference ability of the circuit.

[0021] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Alterations, modifications, substitutions and variations of the above embodiments by a person skilled in the art are all within the scope of the present invention.

Claims

1. A dynamic control circuit with output detection function, characterized in that: One end of the dynamic control circuit is connected to the MCU controller, and the other end is connected to the load. The dynamic control circuit includes a dynamic circuit, a readback detection circuit, and a static control circuit connected to the MCU controller. The dynamic circuit is connected to the MCU controller through a control signal IN1, and is used for dynamic safety output of the circuit. When the MCU controller has continuous high and low level dynamic signal outputs, the dynamic circuit is turned on and generates output; the static control circuit is connected to the MCU controller through a control signal IN2, and is used to quickly cut off the output in an emergency state. When the MCU controller determines that the output is to be cut off urgently, the static control circuit immediately shuts down the dynamic control circuit; the readback detection circuit is connected to the MCU controller through Readback, and is used to detect the output state of the dynamic circuit.

2. The dynamic control circuit with output detection function according to claim 1, characterized in that: The dynamic circuit includes a resistor R1 connected in series with IN1 of the MCU, the resistor R1 is connected to the input cathode of the photoelectric isolation device IC1, and the input anode of the photoelectric isolation device IC1 is connected to the power supply VCC; the output collector of the photoelectric isolation device IC1 is connected in series with the resistor R2 and then connected to the collector of the transistor BG1, and then connected to the power supply V+ after the resistor R4 is connected in series; the output collector of the photoelectric isolation device IC1 is connected to the anode of the diode D1 and the cathode of the diode D2, and the cathode of the diode D1 is connected to the base of the transistor BG1; the The anode is connected to the resistor R3 and then to the base of the transistor BG2; the emitter of the transistor BG1 is connected to the emitter of the transistor BG2, and the emitters of the transistors BG1 and BG2 are connected in series with the capacitor C4 to the cathode of the Schottky diode D7 and the anode of the Schottky diode D6; the anode of the Schottky diode D7 is connected to one end of the capacitor C8 and the output end OUT-; the output emitter of the optoelectronic isolation device IC1 is connected to the collector of the transistor BG2, the cathode of the Schottky diode D6, the other end of the capacitor C8 and the power supply V-.

3. The dynamic control circuit with output detection function according to claim 1, characterized in that: The static control circuit includes a resistor R5 connected in series with IN2 of the MCU, the resistor R5 is connected to the input cathode of the photoelectric isolation device IC3, the input anode of the photoelectric isolation device IC3 is connected to the power supply VCC; the output collector of the photoelectric isolation device IC3 is connected to the input cathode of the photoelectric isolation device IC2; the output emitter of the photoelectric isolation device IC3 is connected to the anode of the diode D5 and the output terminal OUT+.

4. The dynamic control circuit with output detection function according to claim 1, characterized in that: The readback detection circuit includes a photoelectric isolation device IC2, the Readback of the MCU is connected to the output collector of the photoelectric isolation device IC2, the output collector of the photoelectric isolation device IC2 is connected to the power supply VCC in series with a resistor R6; the output emitter of the photoelectric isolation device IC2 is connected to the power supply ground GND; the input anode of the photoelectric isolation device IC2 is connected to the cathode of the diode D5 and the power supply V-; The input cathode of the photoelectric isolation device IC2 is connected to the output collector of the photoelectric isolation device IC3.

5. The dynamic control circuit with output detection function according to claim 2, characterized in that: The dynamic circuit also includes a capacitor C1, a capacitor C2, a diode D3, and a diode D4. The capacitor C1 is connected to the resistor R2 and the cathode of the diode D4. The other end of the capacitor C1 is connected to one end of the capacitor C2 and the emitter of the transistor BG1 and the emitter of the transistor BG2. The other end of the capacitor C2 is connected to the output emitter of the photoelectric isolation device IC1 and the anode of the diode D3. The anode of the diode D4 is connected to the resistor R4 and the collector of the transistor BG1; The cathode of the diode D3 is connected to the collector of the transistor BG2, the cathode of the Schottky diode D6, the other end of the capacitor C8 and the power supply V-.

Images