Programmable direct current (DC) power supply

Abstract

The utility model relates to the technical field of DC power supplies, and discloses a programmable DC power supply comprising a power supply management circuit; a multi-point radiator; a short circuit protection circuit; an overcurrent protection circuit; through the programmable design of the power supply management circuit, all parameter settings can be controlled by an upper computer through an RS485 or RS232 interface instruction, the design of two common mode inductors is adopted, the source management circuit is universal, and the change among different voltages can be realized only by changing a small place, so that the voltages of different specifications are output, and the power supply management circuit is simple in structure and convenient to use. Not only is the size of the power supply reduced, but also safe and reliable input of voltage can be realized through the added relay and common mode inductor. Through the design of the short-circuit protection circuit, after an external output power supply is short-circuited, a current value is increased sharply, so that a comparator exceeds a reference voltage, a short-circuit protection signal is triggered, hardware closes a voltage output function, timing is started, automatic reset output is performed after timing is performed for 3-5 s, and the risk of damage to the circuit and equipment is reduced.

Description

Technical Field

[0001] This utility model relates to the field of DC power supply technology, specifically to a programmable DC power supply. Background Technology

[0002] A DC power supply is a device that maintains a constant voltage and current in a circuit. A DC power supply has the characteristic that the current flow direction remains constant, from the positive terminal to the negative terminal. It can convert other forms of energy into electrical energy to supply the circuit and maintain a steady current flow.

[0003] A search revealed that patent application number CN202321072195.1 discloses a DC power supply device, including an input module, a rectifier module, an output module, a main control module, and a display module. The input module is connected to an AC power source and then to the output module via the rectifier module. The output module outputs 220V DC power to the vacuum circuit breaker. The controller of the main control module controls the on / off state of the input and output modules and adjusts the output power. A sensor assembly is connected to a protection assembly via the controller to detect the operating status of the DC power supply device. When the operating status is abnormal, the controller activates the protection assembly to implement protective measures and disconnects the input module. The display module is connected to the controller to obtain and display the operating status of the DC power supply device. This utility model provides a DC power supply device that enables electric energy storage and electric cancellation of DC-free interlocking in vacuum circuit breakers, improving the operating efficiency of vacuum circuit breakers. It is plug-and-play, easy to operate, highly safe, and widely applicable.

[0004] Current DC power supplies use adjustable resistors to change the voltage and current in the circuit. However, the accuracy of adjustable resistors is limited. When used for a long time or affected by temperature changes, the resistance value will change, which will lead to a decrease in the control accuracy of voltage and current. Frequent adjustments will cause wear or poor disengagement, resulting in unstable resistance values ​​and affecting the stability of voltage and current. Generally, adjustable resistors are large in size and heavy in weight, which is not conducive to their use in compact electronic devices.

[0005] Traditional DC power supplies use fuses connected in the circuit. If a short circuit occurs, the fuse burns out to provide protection, but a new fuse must be replaced to restore the circuit's operation, increasing maintenance costs and workload. Furthermore, during the fuse's melting process, the current may continue to damage the circuit and equipment, meaning the fuse's protective effect is delayed. Therefore, we need to propose a programmable DC power supply. Utility Model Content

[0006] The purpose of this invention is to provide a programmable DC power supply. Through the programmable design of the power management circuit, all parameter settings can be controlled by a host computer via RS485 or RS232 interface commands. It employs a design with two common-mode inductors, and the power management circuit is universal, requiring only minor modifications to achieve voltage changes and thus output voltages of different specifications. This not only reduces the size of the power supply but also ensures safe and reliable voltage input through the addition of relays and common-mode inductors. The short-circuit protection circuit design prevents current surges when the external output power supply is shorted, causing the comparator to exceed the reference voltage and triggering a short-circuit protection signal. The hardware then shuts down the voltage output function and starts a timer, automatically resetting the output after 3-5 seconds. This reduces the risk of damage to the circuit and equipment, thus solving the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a programmable DC power supply, comprising:

[0008] A power management circuit used to regulate and rectify high-voltage AC power into DC power;

[0009] A multi-point heat sink located on the power management circuit and used to improve power conversion efficiency;

[0010] A short-circuit protection circuit that triggers a short-circuit protection signal, shuts down the circuit output, and automatically resets after the external output power is short-circuited.

[0011] An overcurrent protection circuit that shuts off the power supply output when the current exceeds the standard value;

[0012] The short-circuit protection circuit and the overcurrent protection circuit are both electrically connected to the power management circuit, and the short-circuit protection circuit and the overcurrent protection circuit are electrically connected.

[0013] Preferably, the power management circuit includes a rectifier D10, a common-mode inductor L2, and a common-mode inductor L1 connected in sequence. Pin 1 of the rectifier D10 is connected to a 300V high voltage. Pin 2 of the rectifier D10 is connected to pin 4 of the common-mode inductor L2. A fuse F2 is connected between pin 3 of the rectifier D10 and pin 3 of the common-mode inductor L2. Pin 2 of the common-mode inductor L2 is connected to pin 4 of the common-mode inductor L1. Pin 1 of the common-mode inductor L2 is connected to pin 3 of the common-mode inductor L1. A resistor R28 and a relay RLY1 are connected in parallel on pin 4 of the rectifier D10.

[0014] Preferably, the multi-point heat sink includes a socket HS8 for connecting the power supply and external devices, and a heat sink HS4 for dissipating the heat generated by the operation of the circuit components. The socket HS8 has a length of 30mm, and the heat sink HS4 has a size of 35*24*50mm.

[0015] Preferably, the short-circuit protection circuit includes comparators U1A, U1B, U2A, U2B, transistors Q1, Q2, and Q4. A resistor R5 is connected between the base of transistor Q1 and pin 7 of comparator U1B. The collector of transistor Q1 is connected to pin 3 of comparator U2A. A resistor R13 and a diode D6 are connected between pin 3 of comparator U2A and pin 1 of comparator U1A.

[0016] Preferably, diodes D2 and D3 are connected to pin 1 of comparator U2A, one output terminal of diode D3 is connected to transistor Q2, and the other output terminal of diode D3 is connected to comparator U2B.

[0017] A resistor R12 is connected between the base and emitter of transistor Q2, and a resistor R10 is connected between the base of transistor Q2 and one output terminal of diode D3. A capacitor C2 and a resistor R15 are connected between the emitter of transistor Q2 and one output terminal of diode D3.

[0018] A resistor R22 is connected to pin 5 of the comparator U2B. One end of the resistor R22 is connected to a diode D5 and a resistor R23 connected in parallel. A grounded capacitor C3 and a resistor R25 are connected in series between the two ends of the resistor R23. The terminals of the diode D5 and the resistor R23 are connected to the other output terminal of the diode D3.

[0019] Preferably, the overcurrent protection circuit includes comparator U3A and comparator U3B. A resistor R65 is connected between pin 1 of comparator U3A and pin 6 of comparator U3B. A resistor R56 is connected between pin 1 and pin 2 of comparator U3A. A resistor R61A and a resistor R61 are connected in parallel to pin 2 of comparator U3A. A resistor R66 and a resistor R68 are connected to pin 3 of comparator U3A.

[0020] A resistor R62 is connected to pin 5 of comparator U3B. Both resistor R68 and resistor R62 are connected to pin 5 of comparator U1B. A capacitor C27 is connected between pins 6 and 7 of comparator U3B.

[0021] Preferably, the overcurrent protection circuit further includes a comparator U4B, with resistors R38 and R44 connected to pin 5 of the comparator U4B, resistor R30 and capacitor C12 connected between pins 6 and 7 of the comparator U4B, and resistors R35, R36 and R37 connected sequentially to pin 6 of the comparator U4B, with the terminals of resistors R36 and R37 connected to transistor Q2.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] 1. This utility model, through the programmable design of the power management circuit, allows all parameter settings to be controlled by the host computer via RS485 or RS232 interface commands. It adopts a design with two common-mode inductors, and the power management circuit is universal. Only minor modifications are needed to achieve the change between different voltages, thereby outputting different voltage specifications. This not only reduces the size of the power supply, but also ensures safe and reliable voltage input through the addition of relays and common-mode inductors.

[0024] 2. This utility model, through the design of a short-circuit protection circuit, causes a surge in current after the external output power supply is short-circuited, which causes the comparator to exceed the reference voltage, triggering a short-circuit protection signal. The hardware then shuts down the voltage output function and starts timing. After timing for 3-5 seconds, the output is automatically reset, reducing the risk of damage to the circuit and equipment. Attached Figure Description

[0025] Figure 1 This is a circuit diagram of the power management circuit of this utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the multi-point heat sink of this utility model;

[0027] Figure 3 This is a circuit diagram of the short-circuit protection circuit of this utility model;

[0028] Figure 4 This is a circuit diagram of the maximum current protection in the overcurrent protection circuit of this utility model;

[0029] Figure 5 This is a circuit diagram of the current control reference in the overcurrent protection circuit of this utility model. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Please see Figure 1-5 This utility model provides a technical solution: a programmable DC power supply, comprising:

[0032] A power management circuit used to regulate and rectify high-voltage AC power into DC power;

[0033] The power management circuit adopts a programmable design, and all parameter settings can be controlled by a host computer via RS485 or RS232 interface commands. Traditional power supplies change voltage and current through adjustable resistors; this power supply is small in size and utilizes switching power supply technology to increase design efficiency to over 85%, making it more environmentally friendly and energy-efficient. All transformer designs and coil inductance values ​​are innovative, and the circuitry is universal, requiring only minor modifications to achieve different voltage changes and thus output different voltage specifications. Furthermore, relays and common-mode inductors are added to the traditional input mode to ensure safe and reliable input.

[0034] The power management circuit includes a rectifier D10, a common-mode inductor L2, and a common-mode inductor L1 connected in sequence. Pin 1 of the rectifier D10 is connected to a 300V high voltage. Pin 2 of the rectifier D10 is connected to pin 4 of the common-mode inductor L2. A fuse F2 is connected between pin 3 of the rectifier D10 and pin 3 of the common-mode inductor L2. Pin 2 of the common-mode inductor L2 is connected to pin 4 of the common-mode inductor L1. Pin 1 of the common-mode inductor L2 is connected to pin 3 of the common-mode inductor L1. A resistor R28 and a relay RLY1 are connected in parallel on pin 4 of the rectifier D10.

[0035] Relay RLY1 has capacitors C3, C2, C1, resistors R100, R88, R77, and C4 connected in parallel on its 4th pin. Capacitors CY9 and CY5 are connected in series between the two ends of capacitor C4.

[0036] Furthermore, a capacitor CX1 and a resistor R111 are connected in parallel between pins 1 and 2 of the common mode inductor L1, capacitors CY1 and CY2 are connected between pins 2 and 4 of the common mode inductor L1, capacitors CY3 and CY4 are connected between pins 1 and 3 of the common mode inductor L1, and capacitor CX2 is connected between pins 3 and 4 of the common mode inductor L1.

[0037] Capacitors CY9 and CY5 are used for high-frequency noise filtering at the input end, making the input voltage more stable. Resistors R100, R88, and R77 are used for voltage division and filtering to control the stability of the circuit. Relay RLY1 is used to control the on and off of the circuit and can withstand high voltage and high current, increasing the safety of the circuit.

[0038] Rectifier D10 is a bridge rectifier that converts AC to DC, providing rectification of the input current. Capacitors C3, C2, and C1 smooth the output waveform after rectification, reducing ripple and stabilizing the output voltage. Capacitors CX1 and CX2 further smooth the output voltage, reducing ripple and ensuring output stability. Fuse F2 provides overcurrent protection to prevent damage to the equipment under abnormal conditions. Resistor R111 is the load resistor, used for load testing and balancing of the circuit to provide a stable output.

[0039] A multi-point heat sink located on the power management circuit and used to improve power conversion efficiency;

[0040] Multi-point heat sinks separate heat dissipation, improving power conversion efficiency. Traditionally, all components are fixed to a single heat sink with screws using a large heatsink, which is inefficient and difficult to maintain.

[0041] The multi-point heat sink includes a socket HS8 for connecting the power supply and external devices, and a heat sink HS4 for dissipating the heat generated by the operation of the circuit components. The socket HS8 is 30mm long, and the heat sink HS4 is 35*24*50mm in size.

[0042] The HS8 socket provides a power or signal interface, typically used for power supply or data transmission, while the HS4 heat sink prevents the device from overheating, ensuring circuit stability and long-term operational reliability.

[0043] A short-circuit protection circuit that triggers a short-circuit protection signal, shuts down the circuit output, and automatically resets after the external output power is short-circuited.

[0044] The short-circuit protection circuit collects current through a precision resistor and then uses a precision operational amplifier to create a voltage comparator. If the external output power supply is short-circuited, the current will suddenly increase, causing the comparator to exceed the comparison reference voltage, thus triggering the short-circuit protection signal. The hardware then shuts down the voltage output function and starts timing. After 3-5 seconds of timing, the output is automatically reset. The breakthrough in functionality is that the protection function is hardware-controlled, without software intervention, and it can achieve automatic reset.

[0045] The short-circuit protection circuit includes comparators U1A, U1B, U2A, U2B, transistors Q1, Q2, and Q4. A resistor R5 is connected between the base of transistor Q1 and pin 7 of comparator U1B. The collector of transistor Q1 is connected to pin 3 of comparator U2A. A resistor R13 and a diode D6 are connected between pin 3 of comparator U2A and pin 1 of comparator U1A.

[0046] A capacitor C10 and a resistor R4 are connected in parallel to pin 6 of comparator U1B, and resistors R2, R3 and diode D1 are connected to form a closed loop. Resistors R7 and R8 are connected to pin 5 of comparator U1B.

[0047] A resistor R6 is connected to the collector of transistor Q2 to monitor the current flow and generate a corresponding voltage. A resistor R24 ​​is connected between pin 7 of comparator U2B and the base of transistor Q4, and the collector of transistor Q4 is connected to a power switch.

[0048] Diodes D2 and D3 are connected to pin 1 of comparator U2A respectively. One output terminal of diode D3 is connected to transistor Q2, and the other output terminal of diode D3 is connected to comparator U2B.

[0049] A series resistor R20 and a light-emitting diode D4 are connected to pin 1 of comparator U2A. One output terminal of diode D2 is connected to pin 3 of comparator U2A, and the other output terminal of diode D2 is connected to resistor R2.

[0050] A resistor R12 is connected between the base and emitter of transistor Q2, and a resistor R10 is connected between the base of transistor Q2 and one output terminal of diode D3. A capacitor C2 and a resistor R15 are connected between the emitter of transistor Q2 and one output terminal of diode D3.

[0051] A resistor R22 is connected to pin 5 of the comparator U2B. One end of the resistor R22 is connected to a diode D5 and a resistor R23 connected in parallel. A grounded capacitor C3 and a resistor R25 are connected in series between the two ends of the resistor R23. The terminals of the diode D5 and the resistor R23 are connected to the other output terminal of the diode D3.

[0052] The OCP-vref connector is used to set the reference voltage for overcurrent protection. Comparators U1A and U1B are used to compare the current signal with the reference signal and monitor whether the current exceeds the set value. Resistors R7, R8, and R20 are voltage divider and feedback resistors, used to set the comparator gain and threshold.

[0053] Transistors Q1 and Q2 are used for signal amplification and switching control. Transistor Q4 is used to control the LED indicator and the switching of the protection circuit. Diodes D1, D2, D3, D5, and D6 are used for protection circuits to prevent reverse current and overvoltage from damaging the components. Capacitors C10, C20, and C30 are used for filtering and stabilizing voltage to ensure stable circuit operation.

[0054] An overcurrent protection circuit that shuts off the power supply output when the current exceeds the standard value;

[0055] The overcurrent protection circuit continuously collects and detects the current through a precision operational amplifier and compares it with the standard value. Once a large current change is detected, a trigger signal is generated to shut off the power supply output.

[0056] The overcurrent protection circuit includes comparator U3A and comparator U3B. A resistor R65 is connected between pin 1 of comparator U3A and pin 6 of comparator U3B. A resistor R56 is connected between pin 1 and pin 2 of comparator U3A. A resistor R61A and a resistor R61 are connected in parallel to pin 2 of comparator U3A. A resistor R66 and a resistor R68 are connected to pin 3 of comparator U3A.

[0057] A resistor R62 is connected to pin 5 of comparator U3B. Both resistor R68 and resistor R62 are connected to pin 5 of comparator U1B. A capacitor C27 is connected between pins 6 and 7 of comparator U3B.

[0058] Resistors R61 and R62 are used to measure current (sensing resistors). According to Ohm's law, a voltage drop will be generated when current flows through a resistor. This voltage drop is used as a current sensing signal. Resistor R66 is another current sensing resistor used to adjust and calibrate the current value.

[0059] Comparators U3A and U3B ensure that the current does not exceed the set safety value by comparing the current signal with the reference voltage (VREF). When the current exceeds the preset value, the operational amplifier outputs a high level to trigger the subsequent protection mechanism.

[0060] The VREF connector is used to set the reference voltage of the comparator. A stable reference voltage is typically generated by resistors R65 and R67 and the corresponding capacitor (C27) for comparison.

[0061] The ADCiC interface, an analog input, is used to convert the detected current signal into a digital signal so that the microprocessor can process and display the data.

[0062] Capacitors C27 and C38 are used for signal filtering and noise reduction, ensuring that the operational amplifier can operate stably without interference from electrical noise. Resistors R65, R67, and R86 are used to set the gain and adjust the sensitivity of the circuit, while also pulling up or down the signal to ensure the proper operation of the comparator and other components.

[0063] The overcurrent protection circuit monitors the current in real time and compares it with the voltage drop measured by the sensing resistor. When the current exceeds the set value (e.g., 20A, 25A), the operational amplifier triggers the output to control the load switch (e.g., relay) and automatically cut off the power supply to prevent equipment damage or overload.

[0064] The circuit converts analog signals into digital signals for subsequent processing, such as displaying them on a screen or recording data. The circuit design has a response time of 5.3V / μs, ensuring timely response to instantaneous current changes.

[0065] The overcurrent protection circuit also includes a comparator U4B. Resistors R38 and R44 are connected to pin 5 of the comparator U4B. Resistor R30 and capacitor C12 are connected between pins 6 and 7 of the comparator U4B. Resistors R35, R36, and R37 are connected to pin 6 of the comparator U4B in sequence. The terminals of resistors R36 and R37 are connected to transistor Q2.

[0066] Comparator U4B is used to compare the feedback voltage with the reference voltage (Vref) to adjust the output and achieve constant current control. Resistor R44 is a current sensing resistor. The current is measured by the voltage drop (11mV) generated when the current passes through, and this voltage is fed back to the operational amplifier for the control loop.

[0067] Resistors R30, R35, R36, and R37 are used to set the gain, input impedance, and stability to ensure the operational amplifier works properly. Capacitors C12 and C19 act as filters to reduce high-frequency noise and improve the stability of the power supply output.

[0068] The IDAC interface enables more precise current control by adjusting the current output of the digital input, and is connected to the output of comparator U4B to form a feedback loop.

[0069] The short-circuit protection circuit and the overcurrent protection circuit are both electrically connected to the power management circuit, and the short-circuit protection circuit and the overcurrent protection circuit are electrically connected.

[0070] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A programmable DC power supply, characterized in that, include: A power management circuit used to regulate and rectify high-voltage AC power into DC power; A multi-point heat sink located on the power management circuit and used to improve power conversion efficiency; A short-circuit protection circuit that triggers a short-circuit protection signal, shuts down the circuit output, and automatically resets after the external output power is short-circuited. An overcurrent protection circuit that shuts off the power supply output when the current exceeds the standard value; The short-circuit protection circuit and the overcurrent protection circuit are both electrically connected to the power management circuit, and the short-circuit protection circuit and the overcurrent protection circuit are electrically connected.

2. The programmable DC power supply according to claim 1, characterized in that: The power management circuit includes a rectifier D10, a common-mode inductor L2, and a common-mode inductor L1 connected in sequence. Pin 1 of the rectifier D10 is connected to a 300V high voltage. Pin 2 of the rectifier D10 is connected to pin 4 of the common-mode inductor L2. A fuse F2 is connected between pin 3 of the rectifier D10 and pin 3 of the common-mode inductor L2. Pin 2 of the common-mode inductor L2 is connected to pin 4 of the common-mode inductor L1. Pin 1 of the common-mode inductor L2 is connected to pin 3 of the common-mode inductor L1. A resistor R28 and a relay RLY1 are connected in parallel on pin 4 of the rectifier D10.

3. The programmable DC power supply according to claim 1, characterized in that: The multi-point heat sink includes a socket HS8 for connecting the power supply and external devices, and a heat sink HS4 for dissipating the heat generated by the operation of the circuit components. The socket HS8 is 30mm long, and the heat sink HS4 is 35*24*50mm in size.

4. The programmable DC power supply according to claim 1, characterized in that: The short-circuit protection circuit includes comparators U1A, U1B, U2A, U2B, transistors Q1, Q2, and Q4. A resistor R5 is connected between the base of transistor Q1 and pin 7 of comparator U1B. The collector of transistor Q1 is connected to pin 3 of comparator U2A. A resistor R13 and a diode D6 are connected between pin 3 of comparator U2A and pin 1 of comparator U1A.

5. The programmable DC power supply according to claim 4, characterized in that: Diodes D2 and D3 are connected to pin 1 of comparator U2A respectively. One output terminal of diode D3 is connected to transistor Q2, and the other output terminal of diode D3 is connected to comparator U2B. A resistor R12 is connected between the base and emitter of transistor Q2, and a resistor R10 is connected between the base of transistor Q2 and one output terminal of diode D3. A capacitor C2 and a resistor R15 are connected between the emitter of transistor Q2 and one output terminal of diode D3. A resistor R22 is connected to pin 5 of the comparator U2B. One end of the resistor R22 is connected to a diode D5 and a resistor R23 connected in parallel. A grounded capacitor C3 and a resistor R25 are connected in series between the two ends of the resistor R23. The terminals of the diode D5 and the resistor R23 are connected to the other output terminal of the diode D3.

6. The programmable DC power supply according to claim 5, characterized in that: The overcurrent protection circuit includes comparator U3A and comparator U3B. A resistor R65 is connected between pin 1 of comparator U3A and pin 6 of comparator U3B. A resistor R56 is connected between pin 1 and pin 2 of comparator U3A. A resistor R61A and a resistor R61 are connected in parallel to pin 2 of comparator U3A. A resistor R66 and a resistor R68 are connected to pin 3 of comparator U3A. A resistor R62 is connected to pin 5 of comparator U3B. Both resistor R68 and resistor R62 are connected to pin 5 of comparator U1B. A capacitor C27 is connected between pins 6 and 7 of comparator U3B.

7. The programmable DC power supply according to claim 6, characterized in that: The overcurrent protection circuit also includes a comparator U4B. Resistors R38 and R44 are connected to pin 5 of the comparator U4B. Resistor R30 and capacitor C12 are connected between pins 6 and 7 of the comparator U4B. Resistors R35, R36, and R37 are connected to pin 6 of the comparator U4B in sequence. The terminals of resistors R36 and R37 are connected to transistor Q2.

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