Novel resistance-capacitance step-down power supply circuit

Abstract

The utility model discloses a novel resistance-capacitance step-down power supply circuit, which comprises an H-bridge conductive module, a power supply input end connected to one end of the H-bridge conductive module, and a power supply output end connected to the other end of the H-bridge conductive module, the H-bridge conductive module is provided with a first one-way electric conductor and a second one-way electric conductor which are connected in parallel and connected with the power input end, a third one-way electric conductor and a fourth one-way electric conductor which are connected in parallel and connected with the power output end, and a capacitor C1 which is connected between the first one-way electric conductor and the fourth one-way electric conductor and between the second one-way electric conductor and the third one-way electric conductor in series. The switch-on or switch-off and the frequency of the four one-way conductive devices are controlled by the same signal source. Compared with the prior art, the adjustable constant-current power supply has the advantages that through the arrangement of the H-bridge conductive module and the signal source, on the premise of the same capacitance capacity, the frequency can be improved by changing the current frequency, the output current is increased, the conversion efficiency, namely the power factor, is improved, and the power supply circuit can be easily made into an adjustable constant-current power supply.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a power supply circuit, and in particular to a novel resistance-capacitance step-down power supply circuit. Background Art

[0002] In order to meet the DC power demand of some electrical equipment, most electrical equipment is connected to the mains as follows Figure 1 As shown, by utilizing the capacitive reactance generated by capacitor C1C in AC power, utilizing the current limiting and voltage dividing function of capacitor C1C in AC power, and then utilizing a bridge stack or half-bridge rectifier, a low-voltage constant-current DC power can be obtained.

[0003] Among them, the calculation formula of capacitive reactance is: Xc = 1 / (2πfC);

[0004] Xc is the capacitive reactance, unit is Ω ohm; π is the pi, usually taken as 3.14; F is the frequency of AC power, China's mains frequency is 50Hz; C is the capacity of capacitor C1C, unit is farad (F), the capacitor C1C used in the RC step-down power supply is usually in the microfarad (uF) level, 1uF = 0.000001F.

[0005] Taking a 6uF RC step-down power supply as an example, capacitive reactance = 1 / (2x 3.14x AC frequency x capacitor C1C capacity) = 1 / (2x3.14x50x0.000006) = 530Ω;

[0006] When there is a 530Ω resistance in the mains (220V AC), 220V / 530Ω=0.41A. This power supply can provide a constant current of 0.41A. It only needs to be rectified by a bridge stack to obtain a constant current of about 0.41A. This power supply can be used in all occasions that require a constant current source, such as driving LED bulbs, driving motors, etc.

[0007] According to the capacitive reactance formula Xc=1 / (2πfC), we can know that the main factors affecting the capacitive reactance are the AC frequency f and the capacitance C1C. The larger the AC frequency f and the capacitance C1C, the smaller the capacitive reactance, and the greater the constant current that can be provided in the 220V AC mains.

[0008] Based on the above principle explanation, the shortcomings of the existing RC step-down technology are listed below:

[0009] 1. The performance bottleneck is obvious, and the constant current that can be provided is small. In the environment of 220V AC power supply, limited by the capacity of capacitor C1C and the AC frequency f of the AC power supply, the 6uF RC step-down power supply can only provide a constant current of 0.41A;

[0010] 2. After manufacturing, it can only work at constant current, and it is difficult to make an adjustable power supply. When the power supply is manufactured, because the frequency and voltage of the AC power are basically fixed, the capacity of capacitor C1C cannot be changed. This power supply can only work at constant current, and the current cannot be adjusted;

[0011] 3. The energy conversion efficiency is low. The power factor, that is, the conversion efficiency of the power supply, is low. The power factor of the RC step-down power supply in the existing technology is only 0-0.3PF, which makes poor use of AC power and causes great waste. Utility Model Content

[0012] The utility model aims to solve the problem that the circuits of existing electrical equipment connected to the power supply can only work at a constant current due to the certain frequency of the mains power, the energy conversion efficiency is low, the power factor is small, and the utilization rate of the alternating current is poor. The technical problem to be solved by the utility model is to provide a new type of RC step-down power supply circuit that can adjust the output current by adjusting the frequency and can improve the energy conversion efficiency.

[0013] The technical solution adopted by the utility model to solve the above technical problems is: a new type of resistance-capacitance step-down power supply circuit, including an H-bridge conductive module, a power input terminal connected to one end of the H-bridge conductive module, and a power output terminal connected to the other end of the H-bridge conductive module;

[0014] The H-bridge conductive module is provided with a one-way conductive device 1 and a one-way conductive device 2 connected in parallel, a one-way conductive device 3 and a one-way conductive device 4 connected in parallel, and a capacitor C1 connected in series between the one-way conductive device 1 and the one-way conductive device 4, and between the one-way conductive device 2 and the one-way conductive device 3;

[0015] The one-way conductor 1 and the one-way conductor 2 are connected to the power input terminal, and the one-way conductor 3 and the one-way conductor 4 are connected to the power output terminal, and the power input terminal and the power output terminal are connected to direct current;

[0016] The four one-way conductors are all connected to the same signal source, which can control the current frequency and on or off of the four one-way conductors respectively, and the signal source is connected to direct current;

[0017] When powered on, the signal source controls the one-way conductor device 1 and the one-way conductor device 4 to be turned on, and the one-way conductor device 2 and the one-way conductor device 3 to be turned off, or the signal source controls the one-way conductor device 2 and the one-way conductor device 3 to be turned on, and the one-way conductor device 1 and the one-way conductor device 4 to be turned off.

[0018] A further preferred solution of the utility model is that the signal source includes a chip or a transformer or a frequency converter.

[0019] A further preferred solution of the utility model is: the signal source is provided with interface 1 and interface 2, the one-way electrical appliance 1 and the one-way electrical appliance 4 are connected to the interface 1 at the same time, and the one-way electrical appliance 2 and the one-way electrical appliance 3 are connected to the interface 2 at the same time.

[0020] A further preferred solution of the utility model is that the unidirectional conductor includes NMOS or PMOS or triode or MOSFET or IGBT or switch tube.

[0021] A further preferred solution of the utility model is that the power input end and the power output end are connected with a bridge stack, and the bridge stack is connected to the mains or alternating current.

[0022] A further preferred solution of the utility model is that a capacitor C2 is connected in parallel between the bridge stack and the H-bridge conductive module.

[0023] A further preferred solution of the utility model is: a resistor R and the signal source are connected in parallel between the H-bridge conductive module and the capacitor C2, and the resistor R is connected in series with the signal source.

[0024] A further preferred solution of the utility model is: the H-bridge conductive module is connected in series with an electrical device, and the bridge stack, the H-bridge conductive module and the electrical device are connected in series.

[0025] Another technical solution of the utility model is: a novel RC step-down power supply circuit, comprising a bridge stack connected to the mains or AC power, a capacitor C2 connected in series with the bridge stack, and a resistor R connected in parallel with the capacitor C2;

[0026] The bridge stack is connected in series with an H-bridge conductive module and an electrical device, and the H-bridge conductive module is connected in parallel with a relative capacitor C2 of the electrical device;

[0027] The H-bridge conductive module is provided with a one-way conductive device 1 and a one-way conductive device 2 connected in parallel, a one-way conductive device 3 and a one-way conductive device 4 connected in parallel, and a capacitor C1 connected in series between the one-way conductive device 1 and the one-way conductive device 4, and between the one-way conductive device 2 and the one-way conductive device 3;

[0028] The one-way guide electrical appliance 1 and the one-way guide electrical appliance 2 are connected to a power input terminal, and the one-way guide electrical appliance 3 and the one-way guide electrical appliance 4 are connected to a power output terminal, and the power input terminal and the power output terminal are connected to the bridge stack;

[0029] The four unidirectional electrical appliances are all connected to the same signal source, and the signal source can control the current frequency and on or off of the four unidirectional electrical appliances respectively;

[0030] The resistor R is connected in series with the signal source, that is, the resistor R is connected in parallel with the signal source relative capacitor C2;

[0031] When powered on, the signal source controls the one-way conductor device 1 and the one-way conductor device 4 to be turned on, and the one-way conductor device 2 and the one-way conductor device 3 to be turned off, or the signal source controls the one-way conductor device 2 and the one-way conductor device 3 to be turned on, and the one-way conductor device 1 and the one-way conductor device 4 to be turned off.

[0032] A further preferred solution of the utility model is: the signal source includes a chip or a transformer or a frequency converter, and the unidirectional conductor includes an NMOS or a PMOS or a triode or a MOSFET or an IGBT or a switch tube.

[0033] Compared with the prior art, the advantage of the utility model is that, through the setting of the H-bridge conductive module and the signal source, under the premise of the same capacitance, the frequency can be increased by changing the current frequency to increase the output current, thereby improving the conversion efficiency, that is, the power factor, and making the power supply circuit easily made into an adjustable constant current power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be described in further detail below in conjunction with the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and should not be regarded as limiting the scope of the present invention. Furthermore, unless otherwise specified, the drawings only conceptually represent the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0035] Figure 1 It is a circuit diagram of a RC step-down power supply in the prior art;

[0036] Figure 2 This is a circuit diagram of an H-bridge conductive module according to a preferred embodiment of the utility model;

[0037] Figure 3 This is a schematic diagram of circuit connection of a preferred embodiment of the utility model;

[0038] Figure 4 This is one of the state schematic diagrams of the current flow in the H-bridge conductive module of the preferred embodiment of the utility model;

[0039] Figure 5 This is the second state schematic diagram of the current flow in the H-bridge conductive module of the preferred embodiment of the utility model;

[0040] Figure 6 This is one of the state schematic diagrams of the current flow in the circuit of the preferred embodiment of the utility model;

[0041] Figure 7 This is the second state schematic diagram of the current flow in the circuit of the preferred embodiment of the utility model.

[0042] In the figure: 1, bridge stack; 2, H-bridge conductive module, 21, power input terminal, 22, power output terminal. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are only descriptive and exemplary and should not be construed as limiting the protection scope of the present invention.

[0044] It should be noted that like reference numerals denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in subsequent drawings.

[0045] This embodiment mainly describes a novel RC step-down power supply circuit that can adjust the output current by adjusting the frequency and improve the energy conversion efficiency, as follows:

[0046] like Figure 2-7 As shown, the novel RC step-down power supply circuit includes a bridge stack 1 connected to the mains or AC power, the bridge stack 1 connects the L terminal and the N terminal, the bridge stack 1 is composed of D1, D2, D3 and D4, D1, D2, D3 and D4 use M7 diodes, which can be replaced by a single rectifier chip MB10S, the bridge stack 1 has three groups of circuits independently connected in series, and the three groups of circuits are connected in parallel, wherein the first group of circuits includes a capacitor C2, the second group of circuits includes a series resistor R1 and a signal source U1, the third group of circuits includes a series H-bridge conductive module 2 and an electrical device M, the H-bridge conductive module 2 is connected to the signal source U1, preferably, the signal source can be a chip or a transformer or a frequency converter, and the unidirectional conductive device can be an NMOS or PMOS or a triode or a MOSFET or an IGBT or a switch tube.

[0047] In this embodiment, the H-bridge conductive module 2 includes four unidirectional conductive devices and a capacitor C1, C1 is a main step-down capacitor, preferably a bidirectional capacitor CBB capacitor / safety capacitor, and can also be other capacitors or a combination of multiple capacitors, wherein the unidirectional conductive devices Q1 and Q2 are connected in parallel, the unidirectional conductive devices Q3 and Q4 are connected in parallel, and the capacitor C1 is connected in series between the unidirectional conductive devices Q1 and Q4, and between the unidirectional conductive devices Q2 and Q3.

[0048] A power input terminal 21 and a power output terminal 22 connected to the bridge stack 1 are provided at both ends of the H-bridge conductive module 2. The unidirectional conductive device Q1 and the unidirectional conductive device Q2 are connected to the power input terminal 21, and the unidirectional conductive device Q3 and the unidirectional conductive device Q4 are connected to the power output terminal 22. Preferably, the power input terminal 21 and the power output terminal 22 are connected to direct current.

[0049] like Figure 2-3As shown, the signal source U1 is provided with a plurality of pins, wherein pin one is pin 8, pin two is pin 5, pin three is pin 3, and pin four is pin 2. The unidirectional electrical appliances Q1 and Q4 are simultaneously connected at pin 8, and the unidirectional electrical appliances Q2 and Q3 are simultaneously connected at pin 5. The resistor R1 is connected in series between one end of the bridge stack 1 and pin 3 of the signal source U1, and pin 2 of the signal source U1 is connected to the other end of the bridge stack 1.

[0050] Preferably, the signal source U1 can control the current frequency of the four unidirectional electrical appliances respectively, and the signal source U1 can control the four unidirectional electrical appliances to be turned on or off respectively, because the unidirectional electrical appliances Q1 and Q3 are connected to the same pin, and the unidirectional electrical appliances Q2 and Q3 are connected to the same pin.

[0051] like Figure 2 , Figure 4 and Figure 5 As shown, the H-bridge conductive module 2 is an execution module for converting high-voltage direct current into low-voltage direct current, wherein the unidirectional electrical appliances Q1, Q2, Q3 and Q4 form an H-bridge for driving the capacitor C2 main step-down capacitor. In this case, the unidirectional electrical appliances Q1, Q2, Q3 and Q4 use field effect transistors (MOSFETs) of model AO3400, and the capacitor C2 uses a CBB capacitor with a capacity of 6uF.

[0052] When powered on, the H-bridge conductive module 2 in the novel RC step-down power supply circuit has two power-on states.

[0053] Status 1: If Figure 4 As shown, the unidirectional conductor Q1 and the unidirectional conductor Q4 are turned on, and the unidirectional conductor Q2 and the unidirectional conductor Q3 are turned off. The current flows into the left side of the capacitor C1 and flows out from the right side of the capacitor C1. At this time, the capacitor C1 obtains a positive voltage, and after the capacitor C1 is fully charged, the current will be limited from continuing to flow in, and a voltage drop is generated by this effect.

[0054] State 2: If Figure 5 As shown, the unidirectional conductor Q2 and the unidirectional conductor Q3 are turned on, and the unidirectional conductor Q1 and the unidirectional conductor Q4 are turned off. The current flows into the right side of the capacitor C1 and flows out from the left side of the capacitor C1. At this time, the capacitor C1 obtains a negative voltage, and after the negative voltage of the capacitor C1 is fully charged, the current will be limited from continuing to flow in, and a voltage drop is generated by this effect.

[0055] By simply alternating the two states, capacitor C1 can work in AC power with a frequency set by the program, rather than a fixed AC power frequency of 50 Hz. The working frequency of the present invention is completely determined by the outside, and as long as it does not exceed the upper limit of the component, the working frequency is much greater than 50 Hz.

[0056] Resistor R1 and signal source U1 are signal control modules. The function of resistor R1 is to limit current and reduce voltage, and provide low-voltage direct current to signal source U1. Signal source U1 is a signal generator. The high and low level signals generated by signal source U1 can control the on and off of four MOSs: unidirectional electrical appliances Q1, unidirectional electrical appliances Q2, unidirectional electrical appliances Q3 and unidirectional electrical appliances Q4. In this case, pin 8 controls unidirectional electrical appliances Q1 and unidirectional electrical appliances Q4, and pin 5 controls unidirectional electrical appliances Q2 and unidirectional electrical appliances Q3.

[0057] The signal source U1 has been pre-programmed to drive the H-bridge composed of unidirectional electrical appliances Q1, Q2, Q3 and Q4 at a frequency of 200Hz. Specifically, the frequency of 200Hz is like alternating current, changing 200 times in 1 second, with each 0.005 seconds being a positive and negative cycle, and each cycle being divided into a positive half-cycle and a negative half-cycle, with the positive half-cycle being 0.0025 seconds and the negative half-cycle being 0.0025 seconds. The signal source U1 is a NY8A050D microcontroller, which can be programmed by burning a program, and the resistor R1 is a chip resistor with a resistance of 100K.

[0058] The electrical equipment M is the load, usually a motor, LED lamp beads, etc. In this case, it is a DC motor with model RS365.

[0059] When powered on, the new RC step-down power supply circuit has the following states.

[0060] Status 1: If Figure 6 As shown, after 220V AC is introduced into the circuit, the 220V AC is rectified by the bridge stack 1 composed of D1, D2, D3, and D4, and then filtered by the capacitor C3 to obtain high-voltage DC. The high-voltage DC current flows to the resistor R1, the unidirectional electrical appliance Q1, and the unidirectional electrical appliance Q2. The high-voltage DC current flows to the resistor R1 and is limited and reduced in voltage to supply power to the signal source U1. The signal source U1 starts to work and drives the H-bridge composed of the unidirectional electrical appliance Q1, the unidirectional electrical appliance Q2, the unidirectional electrical appliance Q3, and the unidirectional electrical appliance Q4 at a frequency of 200Hz, so that the capacitor C2 obtains the high-voltage AC.

[0061] With 0.005 seconds as a positive and negative cycle, a positive and negative cycle includes a positive half cycle and a negative half cycle. The first 0.0025 seconds is the positive half cycle. At this time, pin 8 of the signal source U1 is at a low level, making the unidirectional conductor Q1 and the unidirectional conductor Q4 turned on. Pin 5 of the signal source U1 is at a high level, making the unidirectional conductor Q1 and the unidirectional conductor Q2 turned off. At this time, the current flow direction is "unidirectional conductor Q1-capacitor C2-unidirectional conductor Q4".

[0062] State 2: If Figure 7As shown, the last 0.0025 seconds is the negative half cycle, at this time, the 8th pin of the signal source U1 is high level, making Q5 and Q8 off, and the 5th pin of the signal source U1 is low level, making the unidirectional conductor Q2 and the unidirectional conductor Q3 on. At this time, the current flows in the direction of "unidirectional conductor Q2-capacitor C2-unidirectional conductor Q3".

[0063] Furthermore, the positive half cycle of 0.0025 seconds and the negative half cycle of 0.0025 seconds together constitute a positive and negative cycle. One positive and negative cycle is 0.005 seconds, 200 times per second, and the frequency is 200 Hz.

[0064] When the H-bridge starts working at a frequency of 200Hz, capacitor C2 can obtain an alternating current with a frequency of 200Hz. According to the characteristic of capacitor "passing AC and blocking DC", capacitor C2 will generate capacitive reactance in the circuit. The formula of capacitive reactance is Xc=1 / (2πfC);

[0065] Capacitive reactance = 1 / (2*3.14*frequency*capacitance);

[0066] According to the above formula, the capacitor C2 will produce a capacitive reactance of 1 / (2*3.14*200*0.000006)=132.69Ω. Using Ohm's law, we know that the current value at this time is: 220V / 132.69Ω=1.65A, which is much larger than 0.41A in the prior art.

[0067] The following comparison is obtained based on actual measurements and calculations:

[0068]

[0069]

[0070] According to the capacitive reactance formula Xc=1 / (2πfC), we can know that what affects the capacitive reactance are the AC frequency f and the capacitance C. The larger the AC frequency f and the capacitance C, the smaller the capacitive reactance. According to Ohm's law, the smaller the capacitive reactance, the greater the constant current obtained in the 220V AC mains.

[0071] Compared with the existing RC step-down technology, the advantages of the present invention are:

[0072] 1. Under the premise of the same capacitance, the frequency can be increased to increase the output current;

[0073] 2. The power factor is much greater than 0.3PF, and the energy conversion efficiency is higher;

[0074] 3. After the power supply is manufactured, the capacitor is usually encapsulated in the shell as hardware and is difficult to replace, so it is difficult to adjust the working current with traditional technology. However, the technology of this patent does not require hardware changes, but only requires software (control signal) adjustment to easily change the AC frequency f, and can easily make an adjustable constant current power supply.

[0075] In the description of the present utility model, it should be noted that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0076] The novel RC step-down power supply circuit provided by the utility model is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the utility model. The description of the above embodiments is only used to help understand the utility model and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified. These improvements and modifications also fall within the protection scope of the claims of the utility model.

Claims

1. A new type of RC step-down power supply circuit, characterized in that: It includes an H-bridge conductive module, a power input terminal connected to one end of the H-bridge conductive module, and a power output terminal connected to the other end of the H-bridge conductive module; The H-bridge conductive module is provided with a one-way conductive device 1 and a one-way conductive device 2 connected in parallel, a one-way conductive device 3 and a one-way conductive device 4 connected in parallel, and a capacitor C1 connected in series between the one-way conductive device 1 and the one-way conductive device 4, and between the one-way conductive device 2 and the one-way conductive device 3; The one-way conductor 1 and the one-way conductor 2 are connected to the power input terminal, and the one-way conductor 3 and the one-way conductor 4 are connected to the power output terminal, and the power input terminal and the power output terminal are connected to direct current; The four one-way conductors are all connected to the same signal source, which can control the current frequency and on or off of the four one-way conductors respectively, and the signal source is connected to direct current; When powered on, the signal source controls the one-way conductor 1 and the one-way conductor 4 to be turned on, and the one-way conductor 2 and the one-way conductor 3 to be turned off, or the signal source controls the one-way conductor 2 and the one-way conductor 3 to be turned on, and the one-way conductor 1 and the one-way conductor 4 to be turned off.

2. The novel RC step-down power supply circuit according to claim 1 is characterized in that: The signal source includes a chip or a transformer or a frequency converter.

3. The novel RC step-down power supply circuit according to claim 2 is characterized in that: The signal source is provided with an interface 1 and an interface 2, the one-way conductive electrical appliance 1 and the one-way conductive electrical appliance 4 are connected to the interface 1 at the same time, and the one-way conductive electrical appliance 2 and the one-way conductive electrical appliance 3 are connected to the interface 2 at the same time.

4. The novel RC step-down power supply circuit according to claim 1 is characterized in that: The unidirectional conductor includes NMOS or PMOS or triode or MOSFET or IGBT or switch tube.

5. The novel RC step-down power supply circuit according to claim 1 is characterized in that: The power input end and the power output end are connected with a bridge stack, and the bridge stack is connected to the mains or alternating current.

6. The novel RC step-down power supply circuit according to claim 5 is characterized in that: A capacitor C2 is connected in parallel between the bridge stack and the H-bridge conductive module.

7. The novel RC step-down power supply circuit according to claim 6 is characterized in that: A resistor R and the signal source are connected in parallel between the H-bridge conductive module and the capacitor C2, and the resistor R is connected in series with the signal source.

8. The novel RC step-down power supply circuit according to claim 5 is characterized in that: The H-bridge conductive module is connected in series with an electrical device, and the bridge stack, the H-bridge conductive module and the electrical device are connected in series.

9. A novel RC step-down power supply circuit, comprising a bridge stack connected to the mains or AC power, a capacitor C2 connected in series with the bridge stack, and a resistor R connected in parallel with the capacitor C2; It is characterized in that The bridge stack is connected in series with an H-bridge conductive module and an electrical device, and the H-bridge conductive module is connected in parallel with a relative capacitor C2 of the electrical device; The H-bridge conductive module is provided with a one-way conductive device 1 and a one-way conductive device 2 connected in parallel, a one-way conductive device 3 and a one-way conductive device 4 connected in parallel, and a capacitor C1 connected in series between the one-way conductive device 1 and the one-way conductive device 4, and between the one-way conductive device 2 and the one-way conductive device 3; The one-way guide electrical appliance 1 and the one-way guide electrical appliance 2 are connected to a power input terminal, and the one-way guide electrical appliance 3 and the one-way guide electrical appliance 4 are connected to a power output terminal, and the power input terminal and the power output terminal are connected to the bridge stack; The four unidirectional electrical appliances are all connected to the same signal source, and the signal source can control the current frequency and on or off of the four unidirectional electrical appliances respectively; The resistor R is connected in series with the signal source, that is, the resistor R is connected in parallel with the signal source relative capacitor C2; When powered on, the signal source controls the one-way conductor 1 and the one-way conductor 4 to be turned on, and the one-way conductor 2 and the one-way conductor 3 to be turned off, or the signal source controls the one-way conductor 2 and the one-way conductor 3 to be turned on, and the one-way conductor 1 and the one-way conductor 4 to be turned off.

10. The novel RC step-down power supply circuit according to claim 9 is characterized in that: The signal source includes a chip or a transformer or a frequency converter, and the unidirectional conductor includes an NMOS or a PMOS or a triode or a MOSFET or an IGBT or a switch tube.

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