CN204304808U - A kind of capacitance-resistance voltage reduction circuit - Google Patents

Abstract

The utility model relates to the technical field of non-isolated auxiliary power supplies, and discloses a resistance-capacitance step-down circuit, which includes an anti-surge discharge circuit, a half-wave rectification circuit, and a linear voltage stabilizing circuit. A soft start circuit is provided between the circuits, the half-wave rectifier circuit is an additional capacitor charging and discharging circuit, and the linear voltage stabilizing circuit is composed of a constant current source voltage stabilizing circuit, a first triode, and a sixth capacitor; After the anti-surge discharge circuit, half-wave rectification circuit, soft-start circuit, and linear stabilization circuit, the anti-surge discharge circuit, half-wave rectification circuit, and soft-start circuit eliminate the surge current in the circuit, and the linear stabilization The voltage circuit is used to step down the constant current output current to provide a stable and reliable power supply for the load. This circuit is composed of discrete components, which are more resistant to high voltage than integrated electronic components and can adapt to special environments. When one of the components fails, it is easy to replace and the maintenance cost is low.

Description

A resistance-capacitance step-down circuit

technical field

The utility model relates to the technical field of non-isolated auxiliary power supply, specifically a high-reliability resistance-capacitance step-down circuit composed of discrete components.

Background technique

There are many switching power supplies on the market now. As a non-isolated auxiliary power supply, the resistance-capacitance step-down circuit uses the AC characteristics of the capacitor to transmit current. Or the energy in the capacitor, but its topology is obviously too complex, consisting of many integrated electronic components, once a problem occurs in one of the integrated electronic components, the entire power system will not work normally, and the cost of replacing spare parts is high .

Utility model content

The purpose of this utility model is to provide a resistance-capacity step-down circuit to solve the problem that once a problem occurs in a certain part of the resistance-capacity step-down circuit composed of integrated electronic components, the entire power supply system will not work normally. The problem of high cost of replacement spare parts.

In order to solve the problems of the technologies described above, the technical solution adopted by the present invention is:

A resistance-capacitance step-down circuit, which includes an anti-surge discharge circuit, a half-wave rectification circuit, and a linear voltage stabilization circuit, a soft-start circuit is provided between the half-wave rectification circuit and the linear stabilization circuit, and the half-wave rectification circuit The circuit is an additional capacitor charging and discharging circuit, and the linear voltage stabilizing circuit is composed of a constant current source voltage stabilizing circuit, a first triode, and a sixth capacitor; the anti-surge discharge circuit is connected to the input terminal of the AC power supply, so The output end of the anti-surge discharge circuit is connected with the input end of the half-wave rectification circuit, the output end of the half-wave rectification circuit is connected with the input end of the soft start circuit, and the soft start circuit The output terminal is connected to the input terminal of the linear voltage stabilizing circuit, and the output terminal of the linear voltage stabilizing circuit is connected to the output terminal; the alternating current passes through the anti-surge discharge circuit, half-wave rectifier circuit, and soft start circuit in sequence , Linear stabilization circuit, the anti-surge discharge circuit, half-wave rectification circuit, and soft-start circuit eliminate the surge current in the circuit, and the linear stabilization circuit performs a step-down constant current output current to provide a stable and reliable power supply for the load .

As a further improvement of the utility model, the anti-surge discharge route is connected in series with the third resistor and the first inductance at the input end of the neutral line of the AC power supply, and the fourth pressure-sensitive resistor connected in parallel between the live line of the AC power supply and the input end of the neutral line. The other end of the first inductance is connected to the first capacitor, and the first bleeder resistor is connected in parallel to both ends of the first capacitor; the third resistor and the first inductance have resistance Inrush current effect, the fourth varistor and the second filter capacitor enhance the stability of the current, and the first bleeder resistor can discharge the energy on the first capacitor within a certain period of time after the power is turned off, The safety and reliability of the circuit are improved.

As a further improvement of the present utility model, the resistance of the first bleed resistor is 5-9 ohms.

As a further improvement of the utility model, the half-wave rectifier circuit consists of a first diode, a second diode, a sixth diode, a seventh diode, a fifth resistor, an eighth resistor, a third capacitor, a fifth capacitor, and a fourth triode, one end of the eighth resistor is connected to one end of the first resistor, the anode of the first diode, and the cathode of the second diode , the other end of the eighth resistor is connected to the base of the fourth transistor, the collector of the fourth transistor is grounded, the emitter of the fourth transistor is connected to the second The anode of the diode is connected to one end of the fifth capacitor, and the other end of the fifth capacitor is connected to the anode of the sixth diode and the cathode of the seventh diode. The anode of the seven diodes is grounded, the cathode of the sixth diode is connected to the cathode of the first diode and one end of the third capacitor, the other end of the third capacitor is grounded, and the The fifth resistor is connected in parallel to both ends of the third capacitor; when the current signal is in the negative half cycle of the AC, the current passes through the seventh diode and the second diode to charge the fifth capacitor, and when the current signal When it turns to the positive half cycle of AC, the fourth triode is turned on, the energy stored in the fifth capacitor is released through the sixth diode, the load and the fourth triode, and the fifth The resistor can discharge the energy on the third capacitor within a certain period of time after the power supply is cut off; the half-wave rectification circuit has the characteristics of half-wave rectification and easy common ground processing, and can output a power close to the full-wave rectification current.

As a further improvement of the utility model, the soft start circuit is composed of a second triode, a second resistor, a seventh resistor, a third Zener diode, and a fourth capacitor, and one end of the seventh resistor is connected to the One end of the third capacitor is connected to the collector of the second transistor, the other end of the seventh resistor is connected to the base of the second transistor and one end of the fourth capacitor, and the fourth capacitor The other end of the second resistor is connected to the ground, the second resistor is connected between the collector and the emitter of the second triode, and the emitter of the second triode is connected to the cathode of the third Zener diode , the anode of the third zener diode is grounded; at the moment when the circuit is powered on, the second resistor acts as a current limiting resistor to suppress the surge current in the circuit, and after the fourth capacitor is charged to a certain value, the second resistor The two transistors are saturated and turned on, the second resistor is short-circuited, the power consumption of the circuit is reduced, and the reliability of the circuit is enhanced.

As a further improvement of the present utility model, the resistance of the second resistor is 100-600 ohms.

As a further improvement of the utility model, the linear voltage stabilizing circuit is composed of a constant current source voltage stabilizing circuit, a first triode, and a sixth capacitor, and the constant current source voltage stabilizing circuit is composed of a third triode, a sixth capacitor Four Zener diodes, the fifth diode, the eighth Zener diode, the sixth resistor, the ninth resistor, and the seventh capacitor, the cathode of the fourth Zener diode and the cathode of the third Zener diode, One end of the sixth resistor is connected to the collector of the first triode, the anode of the fourth Zener diode is connected to the anode of the fifth diode, and the cathode of the fifth diode is connected to the anode of the fifth diode. One end of the ninth resistor is connected to the base of the third transistor, the other end of the ninth resistor is grounded, and the other end of the sixth resistor is connected to the emitter of the third transistor, The collector of the third triode is connected to the cathode of the eighth zener diode, one end of the seventh capacitor, and the base of the first triode, and the emitter of the first triode is connected to the One end of the sixth capacitor is connected to one end of the output terminal, the anode of the eighth Zener diode, the other end of the sixth capacitor, and the other end of the seventh capacitor are grounded and connected to the other end of the output terminal ; The linear voltage regulator circuit provides a stable power supply for the load and resists the surge current.

As a further improvement of the utility model, both the first triode and the third triode are high-voltage triodes.

The beneficial effects of the utility model are:

(1) The circuit is composed of discrete components, which are more resistant to high voltage than integrated electronic components and can adapt to special environments. When one of the components fails, it is easy to replace and the maintenance cost is low;

(2) The surge current is suppressed by the anti-surge discharge circuit and the soft-start circuit to avoid the impact of the surge current on the performance of the load. The soft-start circuit can also improve work efficiency and reliability;

(3) By increasing the charging capacitor, the ability of the circuit to output current is improved;

(4) When the utility model is in use, by changing the withstand voltage of the filter capacitor, the withstand voltage of the piezoresistor, the withstand voltage and capacity of the AC step-down capacitor, and the voltage stabilization value of the voltage regulator diode on the constant current source circuit, it can be used in AC 110V, 220V, 380V system, the output voltage and output current can be changed, the operation is simple, the volume is small, the scope of application is large, and the practicability is strong.

Description of drawings

Fig. 1 is a block diagram of the utility model;

When Fig. 2, the utility model circuit schematic diagram;

In the figure: 1. Anti-surge discharge circuit, 2. Half-wave rectification circuit, 3. Soft start circuit, 4. Linear stabilization circuit.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

A resistance-capacitance step-down circuit as shown in Figure 1 and Figure 2, which includes an anti-surge discharge circuit 1, a half-wave rectification circuit 2, and a linear voltage stabilizing circuit 4, is characterized in that: the half-wave rectification circuit 2 and linear A soft start circuit 3 is provided between the stabilization circuits 4, the half-wave rectification circuit 2 is an additional capacitor charging and discharging circuit, and the linear voltage stabilization circuit 4 is composed of a constant current source voltage stabilization circuit, a first triode Q1, and a sixth capacitor C6; The anti-surge discharge circuit 1 is connected to the input terminal of the AC power supply, the output terminal of the anti-surge discharge circuit 1 is connected to the input terminal of the half-wave rectification circuit 2, and the output terminal of the half-wave rectification circuit is connected to the soft-start circuit 3 The input terminal is connected, the output terminal of the soft start circuit 3 is connected with the input terminal of the linear voltage stabilizing circuit 4, and the output terminal of the linear voltage stabilizing circuit 4 is connected with the output terminal; the AC current passes through the anti-surge discharge circuit 1, half Wave rectification circuit 2, soft start circuit 3, linear stabilization circuit 4, anti-surge discharge circuit 1, half-wave rectification circuit 2, soft start circuit 3 to eliminate the surge current in the circuit, and linear voltage stabilization circuit 4 to step down and constant The output current flows to provide a stable and reliable power supply to the load.

Anti-surge discharge circuit 1 consists of a third resistor R3 connected in series to the input terminal of the neutral line of the AC power supply, a first inductor L1, a fourth varistor R4 connected in parallel between the live line of the AC power supply and the input terminal of the neutral line, and a second filter Composed of capacitor C2, the other end of the first inductor L1 is connected to the first capacitor C1, and the first bleeder resistor R1 is connected in parallel with both ends of the first capacitor C1; the third resistor R3 and the first inductor L1 have the function of anti-surge current , the fourth varistor R4 and the second filter capacitor C2 enhance the stability of the current, and the first bleeder resistor R1 can discharge the energy on the first capacitor C1 within a certain period of time after the power is turned off, which improves the stability of the circuit safety and reliability.

The resistance value of the first bleeder resistor R1 is 5-9 ohms.

The half-wave rectifier circuit 2 is composed of a first diode D1, a second diode D2, a sixth diode D6, a seventh diode D7, a fifth resistor R5, an eighth resistor R8, a third capacitor C3, a Composed of five capacitors C5 and the fourth triode Q4, one end of the eighth resistor R8 is connected with one end of the first resistor R1, the positive pole of the first diode D1, and the negative pole of the second diode D2, and the eighth resistor R8 The other end of the fourth transistor Q4 is connected to the base, the collector of the fourth transistor Q4 is grounded, the emitter of the fourth transistor Q4 is connected to the anode of the second diode D2, the fifth capacitor C5 One end of the fifth capacitor C5 is connected with the anode of the sixth diode D6 and the cathode of the seventh diode D7, the anode of the seventh diode D7 is grounded, and the anode of the sixth diode D6 The negative pole is connected to the negative pole of the first diode D1 and one end of the third capacitor C3, the other end of the third capacitor C3 is grounded, and the fifth resistor R5 is connected in parallel to both ends of the third capacitor C3, when the current signal is in the AC negative half cycle , the current charges the fifth capacitor C5 through the seventh diode D7 and the second diode D2, and when the current signal turns into a positive half cycle of AC, the fourth triode Q4 is turned on, and the fifth capacitor R5 stores The energy released by the sixth diode D6, the load and the fourth triode Q4, the fifth resistor R5 can discharge the energy on the third capacitor C3 within a certain period of time after the power is turned off; the half-wave rectifier circuit 2 It has the characteristics of half-wave rectification and easy ground handling, and can output current close to full-wave rectification.

The soft start circuit 3 is composed of a second triode Q2, a second resistor R2, a seventh resistor R7, a third zener diode D3, and a fourth capacitor C4. One end of the seventh resistor R7 is connected to one end of the third capacitor C3, the second The collectors of the two transistors Q2 are connected, the other end of the seventh resistor R7 is connected with the base of the second transistor Q2 and one end of the fourth capacitor C4, the other end of the fourth capacitor C4 is grounded, and the second resistor R2 is connected between the collector and the emitter of the second transistor Q2, the emitter of the second transistor Q2 is connected to the cathode of the third Zener diode D3, and the anode of the third Zener diode D3 is grounded; At the moment when the circuit is energized, the second resistor R2 acts as a current-limiting resistor to suppress the inrush current in the circuit. After the fourth capacitor C4 is charged to a certain value, the second triode Q2 is saturated and turned on, and the second resistor R2 is short-circuited, and the circuit The power consumption is reduced and the reliability of the circuit is enhanced.

The resistance value of the second resistor R2 is 100-600 ohms.

The linear voltage stabilizing circuit 4 is composed of a constant current source voltage stabilizing circuit, a first triode Q1, and a sixth capacitor C6. The constant current source voltage stabilizing circuit is composed of a third triode Q3, a fourth voltage stabilizing diode D4, a fifth and second Pole tube D5, the eighth zener diode D8, the sixth resistor R6, the ninth resistor R9, and the seventh capacitor C7, the cathode of the fourth zener diode D4 is connected to the cathode of the third zener diode D3, and the sixth resistor R6 One end is connected to the collector of the first triode Q1, the anode of the fourth Zener diode D4 is connected to the anode of the fifth diode D5, the cathode of the fifth diode D5 is connected to one end of the ninth resistor D9, The base of the third transistor Q3 is connected, the other end of the ninth resistor R9 is connected to the ground, the other end of the sixth resistor R6 is connected to the emitter of the third transistor Q3, and the collector of the third transistor Q3 It is connected with the cathode of the eighth voltage stabilizing diode D8, one end of the seventh capacitor C7, and the base of the first transistor Q1, and the emitter of the first transistor Q1 is connected with one end of the sixth capacitor C6, and is connected to the output One end of the terminal is connected, the positive pole of the eighth voltage stabilizing diode D8, the other end of the sixth capacitor C6, and the other end of the seventh capacitor C7 are grounded, and are connected with the other end of the output terminal; the linear voltage stabilizing circuit 4 provides stability for the load. power supply, resist surge current.

Both the first transistor Q1 and the third transistor Q3 are high-voltage transistors.

The utility model can adjust the output voltage and output current by replacing different types of components, and can be used for 110V, 220V, 380V alternating current to take power, and provide stable and reliable power supply for the load.

Claims (8)

1. A resistance-capacitance step-down circuit, which includes an anti-surge discharge circuit (1), a half-wave rectification circuit (2), and a linear voltage stabilization circuit (4), characterized in that: the half-wave rectification circuit (2 ) and the linear stabilization circuit (4) are provided with a soft start circuit (3), the half-wave rectification circuit (2) is an additional capacitor charging and discharging circuit, and the linear stabilization circuit (4) is stabilized by a constant current source The circuit is composed of the first triode (Q1) and the sixth capacitor (C6); the anti-surge discharge circuit (1) is connected to the input terminal of the AC power supply, and the anti-surge discharge circuit (1) The output end is connected to the input end of the half-wave rectification circuit (2), the output end of the half-wave rectification circuit is connected to the input end of the soft start circuit (3), and the soft start circuit (3) The output end of the linear voltage stabilizing circuit (4) is connected to the input end of the linear voltage stabilizing circuit (4) and the output terminal is connected; the alternating current passes through the anti-surge discharge circuit (1 ), half-wave rectification circuit (2), soft-start circuit (3), linear stabilization circuit (4), the anti-surge discharge circuit (1), half-wave rectification circuit (2), soft-start circuit (3) The surge current in the circuit is eliminated, and the linear voltage stabilizing circuit (4) steps down the constant current output current to provide a stable and reliable power supply for the load. 2. The resistance-capacitance step-down circuit according to claim 1, characterized in that: the anti-surge discharge circuit (1) consists of a third resistor (R3) connected in series to the input terminal of the neutral line of the AC power supply, a first inductor (L1), the fourth piezoresistor (R4) connected in parallel between the input terminals of the live line and neutral line of the AC power supply, and the second filter capacitor (C2), the other end of the first inductor (L1) and the first capacitor (C1), the first discharge resistor (R1) is connected in parallel at both ends of the first capacitor (C1); the third resistor (R3) and the first inductor (L1) have the function of anti-surge current, The fourth varistor (R4) and the second filter capacitor (C2) enhance the stability of the current, and the first discharge resistor (R1) can discharge the first capacitor within a certain period of time after the power is turned off. Energy on (C1). 3. The RC step-down circuit according to claim 2, characterized in that: the resistance value of the first bleeder resistor (R1) is 5-9 ohms. 4. The RC step-down circuit according to claim 1 or 2, characterized in that: the half-wave rectifier circuit (2) consists of a first diode (D1), a second diode (D2), a second Sixth diode (D6), seventh diode (D7), fifth resistor (R5), eighth resistor (R8), third capacitor (C3), fifth capacitor (C5), fourth triode (Q4), one end of the eighth resistor (R8) and one end of the first resistor (R1), the anode of the first diode (D1), and the cathode of the second diode (D2) The other end of the eighth resistor (R8) is connected to the base of the fourth transistor (Q4), the collector of the fourth transistor (Q4) is grounded, and the fourth The emitter of the triode (Q4) is connected with the anode of the second diode (D2) and one end of the fifth capacitor (C5), and the other end of the fifth capacitor (C5) is connected with the The anode of the sixth diode (D6) is connected to the cathode of the seventh diode (D7), the anode of the seventh diode (D7) is grounded, and the sixth diode (D6) The cathode of the first diode (D1) is connected to the cathode of the first diode (D1), one end of the third capacitor (C3), the other end of the third capacitor (C3) is grounded, and the fifth resistor (R5) Connected in parallel to both ends of the third capacitor (C3), when the current signal is in the negative half cycle of the AC, the current passes through the seventh diode (D7), the second diode (D2) to the fifth capacitor (C5) is charged, when the current signal turns to the positive half cycle of AC, the fourth triode (Q4) is turned on, and the energy stored in the fifth capacitor (R5) passes through the sixth diode ( D6), the load and the release of the fourth transistor (Q4), the fifth resistor (R5) can release the energy on the third capacitor (C3) within a certain period of time after the power is turned off; The half-wave rectification circuit (2) outputs a current close to the full-wave rectification type. 5. The resistance-capacitance step-down circuit according to claim 4, characterized in that: the soft-start circuit (3) is composed of the second triode (Q2), the second resistor (R2), the seventh resistor (R7) , the third Zener diode (D3), and the fourth capacitor (C4), the set of one end of the seventh resistor (R7), one end of the third capacitor (C3), and the second triode (Q2) The other end of the seventh resistor (R7) is connected to the base of the second triode (Q2) and one end of the fourth capacitor (C4), and the fourth capacitor (C4) The other end is grounded, the second resistor (R2) is connected between the collector and the emitter of the second transistor (Q2), and the emitter of the second transistor (Q2) is connected to the first The negative poles of the three Zener diodes (D3) are connected to each other, and the positive pole of the third Zener diode (D3) is grounded; when the circuit is energized, the second resistor (R2) acts as a current limiting resistor to suppress the surge in the circuit current, after the fourth capacitor (C4) is charged to a certain value, the second triode (Q2) is saturated and turned on, the second resistor (R2) is short-circuited, the power consumption of the circuit is reduced, and the circuit reliability. 6. The RC step-down circuit according to claim 5, characterized in that: the resistance value of the second resistor (R2) is 100-600 ohms. 7. The resistance-capacitance step-down circuit according to claim 5, characterized in that: the linear voltage regulator circuit (4) is composed of a constant current source voltage regulator circuit, a first triode (Q1), a sixth capacitor (C6 ), the constant current source regulator circuit consists of the third transistor (Q3), the fourth regulator diode (D4), the fifth diode (D5), the eighth regulator diode (D8), the sixth Resistor (R6), ninth resistor (R9), seventh capacitor (C7), the cathode of the fourth Zener diode (D4) is connected to the cathode of the third Zener diode (D3), the sixth resistor ( One end of R6) is connected to the collector of the first triode (Q1), the anode of the fourth Zener diode (D4) is connected to the anode of the fifth diode (D5), and the anode of the fourth Zener diode (D5) is connected. The cathode of the fifth diode (D5) is connected to one end of the ninth resistor (D9) and the base of the third triode (Q3), the other end of the ninth resistor (R9) is grounded, and the The other end of the sixth resistor (R6) is connected to the emitter of the third transistor (Q3), and the collector of the third transistor (Q3) is connected to the eighth Zener diode (D8) The negative pole of the seventh capacitor (C7) and the base of the first triode (Q1) are connected, and the emitter of the first triode (Q1) is connected to one end of the sixth capacitor (C6) connected to one end of the output terminal, the anode of the eighth Zener diode (D8), the other end of the sixth capacitor (C6), and the other end of the seventh capacitor (C7) are grounded, and the other end of the output terminal One end is connected; the linear voltage stabilizing circuit (4) provides a stable power supply for the load and resists surge current. 8. The resistance-capacitance step-down circuit according to claim 7, characterized in that: the first triode (Q1) and the third triode (Q3) are all selected from high-voltage triodes.