Stabilized voltage supply circuit with high safety

Abstract

The utility model discloses a stabilized power supply circuit with high safety in the field of low-voltage DC power supply, which comprises a DC socket P1, the socket is connected with a filter circuit, the filter circuit is connected with a delay voltage stabilizing circuit, and the delay voltage stabilizing circuit is connected with an overcurrent protection circuit. The socket P1 is connected to a main power supply, stable voltage required by corresponding modules in the instrument is provided through the time-delay voltage stabilizing circuit after filtering of the filter circuit, time-delay power supply can be realized according to actual requirements, and circuit damage caused by overlarge current is avoided through the over-current protection circuit when short circuit occurs.

Description

TECHNICAL FIELD

[0001] The utility model relates to the safety high steady voltage source circuit in low pressure direct current power supply field. BACKGROUND

[0002] A plurality of modules are arranged in the instrument, different modules need different voltages, and different power supply circuits are used to supply power to the corresponding modules. However, the instrument has only one total power supply, after the plug is plugged into the power supply, all the modules are powered on at the same time, which may cause power oscillation and excessive impact current, causing adverse effects on electronic devices in each module in the instrument. In addition, since the instrument may be short-circuited, a self-restoring fuse is used to realize short-circuit protection, that is, under the condition of continuous short-circuit output, the self-restoring fuse will be burned out, thereby cutting off the output of the power supply. However, frequent short-circuit and overload may accelerate the aging process and shorten the service life. If the circuit is always short-circuited, the fuse will be in a high resistance state or damaged state for a long time, which cannot effectively protect the circuit, and may even completely fail. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at providing a steady voltage source circuit with high safety, which can provide stable power supply voltage and also delay the power-on of the module, and can protect the circuit when short-circuited to avoid damage and failure.

[0004] To achieve the above-mentioned purpose, the utility model provides a steady voltage source circuit with high safety, which comprises a DC socket P1, the socket is connected with a filter circuit, the filter circuit is connected with a delay voltage stabilizing circuit, and the delay voltage stabilizing circuit is connected with an overcurrent protection circuit.

[0005] Compared with the prior art, the utility model has the beneficial effects that the socket P1 is connected with the total power supply, after being filtered by the filter circuit, the delay voltage stabilizing circuit provides the stable voltage required by the corresponding module in the instrument, and can delay the power supply according to the actual demand, when short-circuited, the overcurrent protection circuit is used to avoid excessive current and damage to the circuit.

[0006] As a further improvement of the utility model, the delay voltage stabilizing circuit comprises a switching voltage stabilizer U1, the 1st pin and the 3rd pin of the switching voltage stabilizer U1 are connected with the 3rd pin and the 1st pin of the inductor L1 respectively, the 1st pin and the 2nd pin of the switching voltage stabilizer U1 are connected, the 2nd pin of the inductor L1 is grounded, the 4th pin and the 3rd pin of the inductor L1 are connected with the capacitor C2, the 4th pin of the inductor L1 is connected with the anode of the freewheeling diode D1, the cathode of the freewheeling diode D1 is connected with one end of the resistor R2 and the anode of the capacitor C1 respectively, the cathode of the capacitor C1 is grounded, the other end of the resistor R2 is connected with one end of the resistor R6 and the 9th pin of the switching voltage stabilizer U1 respectively, the other end of the resistor R6 is grounded, the 4th pin and the 5th pin of the switching voltage stabilizer U1 are connected with the delay circuit, the 6th pin and the 7th pin of the switching voltage stabilizer U1 are grounded, the 8th pin of the switching voltage stabilizer U1 is grounded through the series-connected resistor R7 and capacitor C9, the 10th pin, the 12th pin, the 13th pin, the 14th pin and the 0th pin of the switching voltage stabilizer U1 are grounded.

[0007] In this way, the 3rd pin of the switching voltage stabilizer U1 receives the input voltage, the inductor L1 can provide the continuous current to the load through the freewheeling diode D1, so as to avoid the sudden change of the load current and play the role of smoothing the current, and the resistor R2 and R6 constitute a voltage dividing circuit, the voltage value of the final output of the switching voltage stabilizer U1 is realized by adjusting the resistance value of the resistor R2 and R6, so that the output voltage matches the voltage required by the module.

[0008] As a further improvement of the utility model, the delay circuit comprises a resistor R4, one end of the resistor R4 is connected with the filter circuit and the 1st pin of the inductor L1 respectively, the other end of the resistor R4 is connected with the 4th pin of the switching voltage stabilizer U1 and one end of the capacitor C7 respectively, the other end of the capacitor C7 is connected with one end of the capacitor C8 and grounded, the other end of the capacitor C8 is connected with the 5th pin of the switching voltage stabilizer U1.

[0009] In this way, the power supply voltage charges the capacitors C7 and C8 through the resistor R4, and then is input to the 5th pin of the switching voltage stabilizer U1, so as to trigger the signal of the 5th pin of the switching voltage stabilizer U1, so that the 9th pin of the switching voltage stabilizer U1 outputs the voltage required by the module, so that the change of the delay time is realized by changing the capacitance value of the capacitors C7 and C8, and the time difference is formed between the power supply time of other modules, and then the problem of power supply oscillation and excessive impact current is avoided.

[0010] As a further improvement of the utility model, the overcurrent protection circuit comprises a capacitor C4, the positive pole of the capacitor C4 is connected with the positive pole of the capacitor C1, one end of the resistor R1 and the 3-pin of the transistor Q2 respectively, the negative pole of the capacitor C4 is grounded, the other end of the resistor R1 is connected with the 1-pin of the transistor Q2 and the 3-pin of the transistor Q1 respectively, the 1-pin of the transistor Q1 is connected with the 2-pin of the transistor Q2 and the 3-pin of the transistor Q3 respectively, the 2-pin of the transistor Q1 is connected with the positive pole of the capacitor C3 and the 2-pin of the transistor Q3 respectively, the 1-pin of the transistor Q3 is grounded through the resistor R3, and the negative pole of the capacitor C3 is grounded.

[0011] In this way, when the positive pole of the capacitor C3 is short-circuited with the PGND, the current in the circuit rapidly increases, the voltage across R1 increases, then the 3-pin and the 1-pin of Q2 are turned on, then the 3-pin and the 2-pin of Q2 are turned on, the 2-pin of Q2 is connected with the 1-pin of Q1, then Q1 is turned off, the voltage of the positive pole of the capacitor C3 is zero, the output of the whole power supply circuit is zero, the current on R1 rapidly decreases, and Q2 is turned off. As long as the short circuit is not cancelled, the process will be repeated until the short circuit ends, thereby avoiding damage to the circuit caused by the short circuit.

[0012] As a further improvement of the utility model, the filter circuit comprises a capacitor C5, the positive pole of the capacitor C5 is connected with the 1-pin of the DC socket P1, the negative pole of the capacitor C5 is connected with the 2-pin and the 3-pin of the DC socket P1 and grounded, the positive pole of the capacitor C5 is also connected with one end of the resistor R4 and the 1-pin of the inductor L1, and the capacitor C5 is connected with the capacitor C6 in parallel.

[0013] In this way, the input voltage is smoothed by the parallel connection of the capacitor C5 and the capacitor C6, the high-frequency noise in the power supply is filtered out, the voltage fluctuation in the circuit is reduced, and the stability and reliability of the input voltage are improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a delay voltage stabilizing circuit diagram of the utility model.

[0015] Figure 2 It is an overcurrent protection circuit diagram of the utility model. DETAILED DESCRIPTION

[0016] The utility model is further illustrated in connection with the drawings as follows:

[0017] As Figures 1-2 shown in a kind of safe and stable voltage power supply circuit of high, including DC socket P1, socket is connected with filter circuit, filter circuit is connected with delay voltage stabilizing circuit, delay voltage stabilizing circuit is connected with overcurrent protection circuit.

[0018] The delay voltage stabilizing circuit comprises a switching voltage stabilizer U1, the 1st pin and the 3rd pin of the switching voltage stabilizer U1 are connected with the 3rd pin and the 1st pin of an inductor L1 respectively, the 1st pin and the 2nd pin of the switching voltage stabilizer U1 are connected, the 2nd pin of the inductor L1 is grounded, the 4th pin and the 3rd pin of the inductor L1 are connected with a capacitor C2, the 4th pin of the inductor L1 is connected with the positive pole of a freewheeling diode D1, the negative pole of the freewheeling diode D1 is connected with one end of a resistor R2 and the positive pole of a capacitor C1 respectively, the negative pole of the capacitor C1 is grounded, the other end of the resistor R2 is connected with one end of a resistor R6 and the 9th pin of the switching voltage stabilizer U1 respectively, the other end of the resistor R6 is grounded, the 4th pin and the 5th pin of the switching voltage stabilizer U1 are connected with a delay circuit, the 6th pin and the 7th pin of the switching voltage stabilizer U1 are grounded, the 8th pin of the switching voltage stabilizer U1 is grounded through a resistor R7 and a capacitor C9 connected in series, the 10th pin, the 12th pin, the 13th pin, the 14th pin and the 0th pin of the switching voltage stabilizer U1 are grounded.

[0019] The delay circuit comprises a resistor R4, one end of the resistor R4 is connected with a filter circuit and the 1st pin of the inductor L1 respectively, the other end of the resistor R4 is connected with the 4th pin of the switching voltage stabilizer U1 and one end of a capacitor C7 respectively, the other end of the capacitor C7 is connected with one end of a capacitor C8 and grounded, the other end of the capacitor C8 is connected with the 5th pin of the switching voltage stabilizer U1.

[0020] The overcurrent protection circuit comprises a capacitor C4, the positive pole of the capacitor C4 is connected with the positive pole of the capacitor C1, one end of a resistor R1 and the 3rd pin of a triode Q2 respectively, the negative pole of the capacitor C4 is grounded, the other end of the resistor R1 is connected with the 1st pin of the triode Q2 and the 3rd pin of a triode Q1 respectively, the 1st pin of the triode Q1 is connected with the 2nd pin of the triode Q2 and the 3rd pin of a triode Q3 respectively, the 2nd pin of the triode Q1 is connected with the positive pole of a capacitor C3 and the 2nd pin of the triode Q3 respectively, the 1st pin of the triode Q3 is grounded through a resistor R3, the negative pole of the capacitor C3 is grounded.

[0021] The filter circuit comprises a capacitor C5, the positive pole of the capacitor C5 is connected with the 1st pin of a DC socket P1, the negative pole of the capacitor C5 is connected with the 2nd pin and the 3rd pin of the DC socket P1 and grounded, the positive pole of the capacitor C5 is also connected with one end of a resistor R4 and the 1st pin of the inductor L1, the capacitor C5 is connected with a capacitor C6 in parallel.

[0022] In the utility model, P1 is a DC socket, U1, L1 and other peripheral devices constitute a delay voltage stabilizing circuit, Q1, Q2, Q3, R1, R3 constitute an overcurrent protection circuit.

[0023] The 3-pin of the switching voltage stabilizer U1 receives an input voltage, the inductor L1 can provide a continuous current to the load through the freewheeling diode D1 to avoid sudden change of the load current, plays a role of smoothing current, and the resistors R2 and R6 constitute a voltage dividing circuit, the voltage value of the final output of the switching voltage stabilizer U1 is realized by adjusting the resistance values of the resistors R2 and R6, so that the output voltage matches the voltage required by the module.

[0024] Taking the output voltage of 24V as an example, the following is specifically described:

[0025] In the case of normal circuit operation, the 9-pin of the switching voltage stabilizer U1 outputs a 24V voltage, so that P+24V passes through the resistor R1, the 3-pin and the 1-pin of the triode Q1, then passes through the 3-pin and the 1-pin of the triode Q3, and finally passes through the resistor R3 to the ground, thereby forming a loop.

[0026] As shown in Figure 2 When P+24Vout and PGND are short-circuited, the current in the overcurrent protection circuit rapidly increases, the voltage across the resistor R1 increases, the 3-pin and the 1-pin of the triode Q2 are turned on, and then the 3-pin and the 2-pin of the triode Q2 are turned on, and since the 2-pin of the triode Q2 is also connected to the 1-pin of the triode Q1, the triode Q1 does not meet the conduction condition (the conduction condition of the triode Q1 is that the 3-pin is higher than the 1-pin by 0.7V). Thus, the entire overcurrent protection circuit loop (P+24V, resistor R1, 3-pin and 1-pin of the triode Q1, 3-pin and 1-pin of the triode Q3, resistor R3) will not be turned on. Therefore, the current on the resistor R1 will rapidly decrease, which is insufficient to turn on the 3-pin and the 1-pin of the triode Q2, so that the voltage of the positive electrode of the capacitor C3 is zero, and thus the output of the entire power supply circuit is zero, so that the current on the resistor R1 rapidly decreases, thereby turning off the triode Q2. As long as the short circuit is not cancelled, the process will continue to repeat until the short circuit condition is over, thereby avoiding damage to the circuit.

[0027] The utility model can provide stable power supply voltage, and also delay the power supply to the module, and can protect the circuit in short circuit to avoid damage and failure.

[0028] The utility model is not limited to the above-mentioned embodiments, on the basis of the technical scheme of the disclosure, the skilled in the art can make some substitutions and deformations to some technical features according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the utility model.

Claims

1. A highly secure regulated power supply circuit, characterized in that: Includes DC socket P1, which is connected to a filter circuit, which is connected to a time-delay voltage regulator circuit, and the time-delay voltage regulator circuit is connected to an overcurrent protection circuit. The time-delay voltage regulator circuit includes a switching regulator U1. Pins 1 and 3 of the switching regulator U1 are connected to pins 3 and 1 of inductor L1, respectively. Pins 1 and 2 of the switching regulator U1 are connected. Pin 2 of inductor L1 is grounded. A capacitor C2 is connected between pins 4 and 3 of inductor L1. Pin 4 of inductor L1 is connected to the positive terminal of freewheeling diode D1. The negative terminal of freewheeling diode D1 is connected to one end of resistor R2 and the positive terminal of capacitor C1, respectively. The negative terminal of capacitor C1 is grounded. The other end of resistor R2 is connected to one end of resistor R6 and pin 9 of switching regulator U1, respectively. The other end of resistor R6 is grounded. Pins 4 and 5 of the switching regulator U1 are connected to a time-delay circuit. Pins 6 and 7 of the switching regulator U1 are grounded. Pin 8 of the switching regulator U1 is grounded through a series resistor R7 and capacitor C9. Pins 10, 12, 13, 14, and 0 of the switching regulator U1 are grounded.

2. The high-safety regulated power supply circuit according to claim 1, characterized in that: The delay circuit includes resistor R4. One end of resistor R4 is connected to the filter circuit and pin 1 of inductor L1. The other end of resistor R4 is connected to pin 4 of switching regulator U1 and one end of capacitor C7. The other end of capacitor C7 is connected to one end of capacitor C8 and grounded. The other end of capacitor C8 is connected to pin 5 of switching regulator U1.

3. The high-safety regulated power supply circuit according to claim 2, characterized in that: The overcurrent protection circuit includes capacitor C4. The positive terminal of capacitor C4 is connected to the positive terminal of capacitor C1, one end of resistor R1, and pin 3 of transistor Q2. The negative terminal of capacitor C4 is grounded. The other end of resistor R1 is connected to pin 1 of transistor Q2 and pin 3 of transistor Q1. Pin 1 of transistor Q1 is connected to pin 2 of transistor Q2 and pin 3 of transistor Q3. Pin 2 of transistor Q1 is connected to the positive terminal of capacitor C3 and pin 2 of transistor Q3. Pin 1 of transistor Q3 is grounded through resistor R3. The negative terminal of capacitor C3 is grounded.

4. The high-safety regulated power supply circuit according to claim 3, characterized in that: The filter circuit includes capacitor C5. The positive terminal of capacitor C5 is connected to pin 1 of DC socket P1, and the negative terminal of capacitor C5 is connected to pins 2 and 3 of DC socket P1 and grounded. The positive terminal of capacitor C5 is also connected to one end of resistor R4 and pin 1 of inductor L1. Capacitor C5 is connected in parallel with capacitor C6.

Images