CN106057575B - The power save unit of alternating current electromagnetic valve or A.C. contactor - Google Patents

Abstract

The invention discloses a power-saving unit of an AC solenoid valve or an AC contactor, which is a four-port network consisting of a first input port N1, a second input port N2, a first output port T1, a second output port T2, an instantaneous It consists of variable voltage suppression diode TVS, AC-DC conversion circuit 101, control pulse generation circuit 102, and pulse-controlled special-shaped bridge circuit 103.

Description

Power saving unit for AC solenoid valve or AC contactor

technical field

The invention relates to the field of low-voltage electrical appliances, in particular to an "electricity-saving unit for an AC solenoid valve or an AC contactor" with an electricity-saving function.

Background technique

AC solenoid valve (AC solenoid valve) is a type of solenoid valve, and it is a low-voltage electrical appliance widely used in household appliances and industrial control equipment. Its characteristic is to connect AC voltage at its input end, and use the electromagnetic force generated by the excitation coil to drive the valve to open or close.

The AC solenoid valve is mainly composed of an excitation coil, a valve core and a return spring. Figure 1a and Figure 1b are schematic diagrams of AC solenoid valves controlling fluid (air or liquid) on and off; Figure 2a and Figure 2b are schematic diagrams of AC hydraulic solenoid valves used in hydraulic equipment controlling the flow of "hydraulic oil".

Combined with Figure 1a: when the A1 and A2 terminals of the excitation coil are connected to AC220V, AC110V or AC380V voltage (hereinafter referred to as AC220V, AC110V or AC380V as AC voltage), the electromagnetic force generated by it pushes the valve core downward to overcome the resistance of the return spring When it moves to the set position, the piston connected with the spool also moves down, the AC solenoid valve is opened, and its "inlet" and "outlet" are connected.

Combined with Figure 1b: when the AC voltage in the excitation coil is turned off, the valve core loses its magnetic force, and moves up due to the action of the return spring, and the piston also moves up accordingly. The AC solenoid valve "resets" and its "entrance" with "Exit" off.

Combined with Figure 2a: when the A1 and A2 ends of the excitation coil of the hydraulic solenoid valve are connected to the AC voltage, the electromagnetic force generated by it pushes the valve core to overcome the resistance of the return spring and move to the right to the set position. The group piston also moves right thereupon, and 2 ports and 3 ports, 1 port and 4 ports of the described hydraulic solenoid valve are just connected.

Combined with Figure 2b: when the AC voltage in the excitation coil of the hydraulic solenoid valve is turned off, the valve core loses its magnetic force, and is moved to the left by the action of the return spring, and the piston also moves to the left. The hydraulic solenoid valve is "reset", and its Port 1 and port 2, port 4 and port 5 are connected.

Alternating Current Contactor (Alternating Current Contactor) is also a widely used low-voltage electrical appliance. Its working principle is to use an electromagnet to drive a movable contact to make a normally closed contact or a normally open contact. open contact) to separate or close to cut off or connect the circuit. It is suitable for starting or controlling three-phase induction motors and other electrical equipment.

Figure 3 is a working principle diagram of an AC contactor, which is mainly composed of a moving iron core, a static iron core, an excitation coil, a return spring, a moving contact, a normally closed contact, and a normally open contact. When the excitation coil is connected to the AC voltage, the moving iron core is closed with the static iron core (or moved to the set position) by the magnetic force generated by the excitation coil, and the moving contact linked with the moving iron core is also in line with the normal contact. When the open contact is closed, the external circuit is connected through this normally open contact; when the AC voltage on the exciting coil is disconnected, the moving iron core loses its magnetic force and is separated from the static iron core by the action of the return spring, the normally open contact When the reset point is disconnected, the external circuit will be cut off accordingly.

To sum up, it can be seen that the working principle of AC solenoid valve and AC contactor is basically the same, and their working process can be divided into three stages: "suction", "holding" and "reset".

In order to facilitate the description of their working process, the "spool" of the AC solenoid valve and the "moving iron core" of the AC contactor are collectively referred to as the "magnetic drive"; the "excitation coil" of the AC solenoid valve and the AC contactor They are collectively referred to as "excitation coil L".

1. Pull-in: The excitation coil L is connected to the AC voltage, and the magnetic drive is driven by the electromagnetic force to move to the set position. At this stage, in order to overcome the inertia and the elastic force of the return spring, the AC voltage must provide a relatively large power (hereinafter referred to as the "pulling power"), so that the magnetic drive can reach the set position.

2. Holding: The excitation coil L continues to be connected to the AC voltage, and the magnetic drive remains at the set position. At this stage, the AC voltage only needs to provide a small power (hereinafter referred to as "holding power"), and the magnetic drive can continue to maintain the set position. If at this stage, the AC voltage provides excessive holding power, it will cause waste of electric energy and lead to undue heating of the excitation coil L;

3. Reset: The excitation coil L is disconnected from the AC voltage, and the magnetic drive is "reset" - returning to the initial position.

Conventional AC solenoid valves and AC contactors have the following serious disadvantages because the excitation coil L is supplied with the same AC voltage during the pull-in and hold stages:

1. Unnecessary power consumption: As mentioned above, in the pull-in and holding stages, the conventional AC solenoid valve and the excitation coil L of the AC contactor are all connected with the "same" AC voltage, so that the holding power is too large. Caused unnecessary power loss;

2. Heating: The evil result of unnecessary power loss is "heating and heating". In severe cases, it will even burn the excitation coil L;

3. There is annoying humming noise.

Aiming at the status quo of conventional AC solenoid valves and conventional AC contactors, the goal of the present invention is to "apply electronic technology to transform traditional industries" and design a "power-saving AC solenoid valve or AC contactor" with power-saving functions. unit", and then combine it with a conventional AC solenoid valve or a conventional AC contactor to achieve the beneficial effects of power saving and noise suppression.

Contents of the invention

The method of the present invention to achieve the above object is: a power-saving unit of an AC solenoid valve or an AC contactor, which is a four-port network, consisting of a first input port N1, a second input port N2, a first output port T1, a second Two output ports T2, a transient voltage suppression diode TVS, an AC-DC conversion circuit 101, a control pulse generating circuit 102, and a pulse-controlled special-shaped bridge circuit 103 are characterized in that: the first input port N1 and the AC voltage connected to the P1 end of the AC voltage, and the second input port N2 is connected to the P2 end of the AC voltage; one end of the transient voltage suppression diode TVS is connected to the first input port N1, and the other end is connected to the second input port N2 ; The first output port T1 is connected to the A1 end of the excitation coil L, and the second output port T2 is connected to the A2 end of the excitation coil L; the 1 end of the AC-DC conversion circuit 101 is connected to the The output port is connected, and there are two connection methods, the first one: connected with the second output port T2, the second one: connected with the first output port T1; the 3 ends of the control pulse generating circuit 102 are connected with the AC -The 2 terminals of the DC conversion circuit 101 are connected, and the 4 terminals are connected with the 5 terminals of the pulse-controlled special-shaped bridge circuit 103; the AC1 terminal of the pulse-controlled special-shaped bridge circuit 103 is connected with the first input port N1, and the AC2 terminal is connected with the first input port N1. The two input ports N2 are connected, the DC1 end is connected with the first output port T1, and the DC2 end is connected with the second output port T2; the AC-DC conversion circuit 101 and the control pulse generation circuit 102 are all provided with a connection with the first output port T2. The port to which the two input ports N2 are connected.

The "power-saving unit for AC solenoid valve or AC contactor" can be combined with conventional AC solenoid valve or conventional AC contactor according to the above method to achieve the beneficial effects of power saving and noise suppression.

Described AC-DC conversion circuit 101 can adopt multiple circuit structure, and the present invention preferably following circuit structure: it is made up of first capacitor C1, the 4th capacitor C4, the 4th diode D4, the 5th diode D5 , 1 end and 2 ends; wherein, one end of the fourth capacitor C4 is connected to the first end, and the other end is in phase with the positive pole of the fourth diode D4 and the negative pole of the fifth diode D5 connection; both the cathode of the fourth diode D4 and the anode of the first capacitor C1 are connected to terminal 2; the anode of the fifth diode D5 and the cathode of the first capacitor C1 are both connected to the second input port N2.

The control pulse generating circuit 102 can adopt various circuit structures, and the present invention preferably adopts the following one: it consists of a second resistor R2, a third resistor R3, a fourth resistor R4, a second capacitor C2, transistors V1, 3 terminal and 4 terminals; wherein, one terminal of the second resistor R2 and one terminal of the third resistor R3 are connected to the terminal 3; the other terminal of the third resistor R3, one terminal of the fourth resistor R4, and the second capacitor C2 One end of the second capacitor C2 is connected to the base of the transistor V1; the other end of the second resistor R2 and the collector of the transistor V1 are connected to the 4th end; the other end of the second capacitor C2, the other end of the fourth resistor R4, and the transistor V1 The emitters of are all connected to the second input port N2.

The pulse-controlled special-shaped bridge circuit 103 is composed of a first diode D1, a second diode D2, a third diode D3, a field effect transistor FET (Field Effect Transistor, FET), a third capacitor C3, AC1 terminal, AC2 terminal, DC1 terminal, DC2 terminal, and 5 terminals; wherein, the negative pole of the first diode D1 and the positive pole of the second diode D2 are connected to the AC1 terminal; the negative pole of the second diode D2, One end of the third capacitor C3 is connected to the DC1 terminal; the positive pole of the third diode D3 and the positive pole of the first diode D1 are connected to the DC2 terminal; the negative pole of the third diode D3 is connected to the field effect tube FET The drain of the effect tube FET is connected to the terminal 5; the other end of the third capacitor C3 and the source of the effect tube FET are connected to the AC2 terminal.

The field effect transistor FET can use other switching devices such as a unidirectional thyristor (Silicon Controlled Rectifier, SCR), a bidirectional thyristor (Triode AC Switch, TRIAC), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor) , IGBT), electron injection enhanced gate transistor (Injection Enhanced Gate Tansistor, IEGT), static induction thyristor (Static Induction Thyristor, SITH) or switching triode instead.

Apply the present invention, can obtain following beneficial effect:

1. High efficiency and power saving:

In order to illustrate the efficient power-saving efficiency of the present invention, we have done the following comparative tests:

(1) The commercially available BY-03 hydraulic conventional AC solenoid valve (hereinafter referred to as "conventional valve") has a power consumption of 61.2W;

According to the method referred to in the present invention, that is: the above-mentioned "conventional AC electromagnetic valve for BY-03 type hydraulic pressure" adds the new electromagnetic valve (hereinafter referred to as "the power-saving unit of AC electromagnetic valve or AC contactor") formed Referred to as "the present invention A"), the power consumption is 1.2W;

Compared with the "conventional valve", the power saving efficiency of "the present invention A" can reach 98%.

(2) Commercially available international famous brand LC1-D1810 AC contactor (referred to as "international famous brand"): power consumption is 2.6W;

According to the method referred to in the present invention, that is: the above-mentioned international famous brand LC1-D1810 type AC contactor plus the new AC contactor (hereinafter referred to as "this Invention B"), the power consumption is 0.2W; compared with "international famous brand", the power saving efficiency of "invention B" can reach 92%.

2. Quiet and noiseless:

"Invention A" and "Invention B" are silent and have no audible noise during operation. Commercially available "conventional valves" and "international famous brand" have obvious and audible AC noise during operation.

3. Low heat operation: the present invention has the function of high efficiency and power saving, saves electric energy, and must run with low heat.

4. It can challenge the "international famous brand" in the field of AC solenoid valve and AC contactor with sufficient technical indicators.

Description of drawings

Fig. 1 a is the schematic diagram of the energized state of the conventional AC solenoid valve used for gas or liquid;

Fig. 1b is a schematic diagram of a power-off state of a conventional AC solenoid valve for gas or liquid;

Fig. 2a is a schematic diagram of the energized state of a conventional AC solenoid valve for hydraulic pressure;

Fig. 2b is a schematic diagram of a power-off state of a conventional AC solenoid valve for hydraulic pressure;

Figure 3 is a working principle diagram of a conventional AC contactor;

Fig. 4 is a principle block diagram of the present invention; There are two kinds of connection methods between "end 1" of the AC-DC conversion circuit 101 in the figure and related circuits, the first kind: be connected with the second output port T2; the second kind: It is connected with the first output port T1.

Fig. 5 is the schematic circuit diagram of embodiment 1 of the present invention;

Fig. 6 is the schematic circuit diagram of embodiment 2 of the present invention;

Figure 7a is an AC voltage waveform;

FIG. 7 b is a pulse waveform diagram output by the control pulse generating circuit 102 .

Detailed ways

Below in conjunction with accompanying drawing, illustrate the embodiment of the present invention.

Fig. 4 is a schematic block diagram of the present invention, in which: L is the excitation coil in a conventional AC solenoid valve or a conventional AC contactor, and A1 and A2 are its two connection ports.

Combined with Figure 4: a power-saving unit for an AC solenoid valve or an AC contactor, which is a four-port network consisting of a first input port N1, a second input port N2, a first output port T1, a second output port T2, The transient voltage suppression diode TVS, AC-DC conversion circuit 101, control pulse generating circuit 102, and pulse-controlled special-shaped bridge circuit 103 are characterized in that: the first input port N1 is connected to the P1 terminal of the AC voltage , the second input port N2 is connected to the P2 end of the AC voltage; one end of the transient voltage suppression diode TVS is connected to the first input port N1, and the other end is connected to the second input port N2; An output port T1 is connected to the A1 end of the excitation coil L, and a second output port T2 is connected to the A2 end of the excitation coil L; end 1 of the AC-DC conversion circuit 101 is connected to the output port, There are two connection methods, the first one: connected to the second output port T2, the second one: connected to the first output port T1; the 3 terminals of the control pulse generating circuit 102 are connected to the AC-DC conversion circuit 101 The 2 terminals of the pulse-controlled special-shaped bridge circuit 103 are connected to each other, and the 4 terminals are connected to the 5-terminal of the pulse-controlled special-shaped bridge circuit 103; the AC1 terminal of the pulse-controlled special-shaped bridge circuit 103 is connected to the first input port N1, and the AC2 terminal is connected to the second input port N2. connection, the DC1 end is connected with the first output port T1, and the DC2 end is connected with the second output port T2; the AC-DC conversion circuit 101 and the control pulse generation circuit 102 are all provided with a second input port N2 phase The port to connect to.

The power-saving unit of the AC solenoid valve or the AC contactor is combined with the conventional AC solenoid valve or the conventional AC contactor according to the above method, so that the beneficial effects of power saving and noise reduction can be obtained.

FIG. 5 is a schematic circuit diagram of Embodiment 1 of the present invention. In conjunction with Fig. 5: in the present embodiment 1:

There is a transient voltage suppression diode TVS at the input end of the AC voltage. With this setting, the following beneficial effects can be achieved: Suppress the external "transient voltage" - if the transient voltage or AC voltage generated by lightning strikes is caused by an inductive load For example, the transient voltage generated by the self-induced electromotive force when the motor starts and shuts down enters the present invention, and some devices such as transistors, field effect transistors, capacitors, etc. may be broken down and damaged. After the transient voltage suppression diode TVS is set at the input end of the AC voltage, when the voltage value of the "transient voltage" that enters from the outside is higher than the breakdown voltage of the transient voltage suppression diode TVS, it is equivalent to a short circuit , the present invention is protected.

4 and 5, in the present invention, the system composed of AC-DC conversion circuit 101 and control pulse generating circuit 102 is called "control system", and the current i2 flowing through the "control system" is called "control system". Current i2".

The first capacitor C1, the fourth capacitor C4, the fourth diode D4, the fifth diode D5, terminals 1 and 2 form an AC-DC conversion circuit 101; wherein, one terminal of the fourth capacitor C4 is connected to The 1 end is connected, and the other end is connected to the positive pole of the fourth diode D4 and the negative pole of the fifth diode D5; the negative pole of the fourth diode D4 and the positive pole of the first capacitor C1 are connected to the 2 The anode of the fifth diode D5 and the cathode of the first capacitor C1 are both connected to the second input port N2.

In the first embodiment, "terminal 1" of the AC-DC conversion circuit 101 is connected to the second output port T2.

The DC voltage output by the AC-DC conversion circuit 101 is Vcc, the terminal 2 is its positive terminal, and the second input port N2 is its negative terminal.

The AC-DC conversion circuit 101 has the following two functions in the present invention: first, it provides the DC voltage Vcc for the "control system";

The second resistor R2, the third resistor R3, the fourth resistor R4, the second capacitor C2, the triode V1, terminals 3 and 4 form the control pulse generating circuit 102; wherein, one terminal of the second resistor R2, the third One end of the resistor R3 is connected to the terminal 3; the other end of the third resistor R3, one end of the fourth resistor R4, and one end of the second capacitor C2 are all connected to the base of the transistor V1; the other end of the second resistor R2, The collectors of the triode V1 are all connected to terminals 4; the other end of the second capacitor C2, the other end of the fourth resistor R4, and the emitter of the triode V1 are all connected to the second input port N2.

5, in this control pulse generating circuit 102, when the voltage Vb between the base and the emitter of the transistor V1 (in this embodiment, a silicon transistor is selected) is less than 0.7V, that is, when Vb<0.7V, the The triode V1 is in the cut-off state, and the voltage Vg on the collector is "high level", Vg≈Vcc; on the contrary, the voltage Vb between the base and the emitter is equal to or greater than 0.7V, that is, Vb≥0.7V At this time, the transistor V1 is in the conduction state, and the voltage Vg on its collector is "low level", Vg≈0. The waveform of Vg is shown in Fig. 7b.

Those in this profession should be clear: the triode V1 in the control pulse generating circuit 102 can be replaced by a 555 integrated time base circuit and an integrated operational amplifier such as LM393;

The first diode D1, the second diode D2, the third diode D3, the field effect tube FET, the third capacitor C3, the AC1 terminal, the AC2 terminal, the DC1 terminal, the DC2 terminal, and the 5 terminal form a pulse control profile Bridge circuit 103; wherein, the negative pole of the first diode D1 and the positive pole of the second diode D2 are connected to the AC1 terminal; the negative pole of the second diode D2 and one end of the third capacitor C3 are all connected to the DC1 terminal The anode of the third diode D3 and the anode of the first diode D1 are connected to the DC2 terminal; the cathode of the third diode D3 is connected to the drain of the field effect transistor FET; The gate is connected to terminal 5; the other terminal of the third capacitor C3 and the source of the effect tube FET are both connected to terminal AC2.

The pulse-controlled special-shaped bridge circuit 103 is a special-shaped bridge circuit controlled by the pulse voltage Vg output by the control pulse generating circuit 102 . The AC1 end and DC1 end are bridge arm 1, which is composed of the second diode D2; the AC1 end and DC2 end are bridge arm 2, which is composed of the first diode D1; the AC2 end and DC1 end are bridge arm 3, which is composed of The third capacitor C3 is formed; the AC2 end and the DC2 end are the bridge arm 4, which is formed by connecting the third diode D3 and the field effect transistor FET in series.

The bridge arm 4 is controlled by the pulse voltage Vg: when Vg is high level, it is approximately short circuit; when Vg is low level, it is approximately open circuit.

It should be clear to those skilled in the art that the field effect transistor FET in bridge arm 4 can use other switching devices such as unidirectional thyristors, bidirectional thyristors, insulated gate bipolar transistors, electron injection enhanced gate transistors, static induction thyristors or switching transistors instead.

Below, in conjunction with accompanying drawing, set forth the course of work of present embodiment 1:

1. Suction:

Combined with Figure 5, Figure 7a, Figure 7b:

When t=t1, the AC voltage is turned on, and the control current i2 is along the P1-N1 terminal-AC1 terminal-D2-DC1 terminal-T1 terminal-A1-excitation coil L-A2-T2 terminal-DC2 terminal-1 terminal-C4 - D4 - 2 terminals - (multiple paths such as R3) - N2 terminal - the path of P2 circulates, the DC voltage Vcc output by the AC-DC conversion circuit 101 is quickly established, and when t=t2, it reaches the set value (for example DC15V) .

The DC voltage Vcc charges the second capacitor C2 through the third resistor R3, and the voltage on the second capacitor C2, that is, the voltage Vb between the base and the emitter of the transistor V1, gradually rises as the charging progresses.

In the time domain of t2～t6, Vb<0.7V, the triode V1 is in the off state, the voltage Vg on its collector is "high level", and the field effect transistor FET in the pulse-controlled special-shaped bridge circuit 103 is in the on state , the pull-in current i1 is along the P1-N1 terminal-AC1 terminal-D2-DC1 terminal-T1 terminal-A1-excitation coil L-A2-T2 terminal-DC2 terminal-D3-field effect tube FET-AC2 terminal-N2 terminal- The path of P2 flows through, the excitation coil L charges and stores energy, and the AC voltage provides "pulling power" for this embodiment through the field effect transistor FET.

From the above analysis, it can be seen that the control current i2 flows through the excitation coil L and is in the same direction as the pull-in current i1. In other words: during the pull-in process, the control current i2 in the present invention is “utilized”—to assist the pull-in current i1 to complete the pull-in process of the first embodiment.

The above-mentioned "magnetic drive part" is subjected to the action of the electromagnetic force generated by the excitation coil L and starts to "pull in and start".

In the time domain from t3 to t4, the AC voltage is in the negative half cycle when P1 is negative and P2 is positive, and the third diode D3 is cut off. Since the current i in the excitation coil L cannot be mutated, it will continue to flow along the A1-excitation coil L-A2-T2 terminal-DC2 terminal-D1-AC1 terminal-D2-DC1 terminal-T1 terminal-A1 path—called " "Follow current", or the discharge and release of energy of the excitation coil L; the "magnetic drive" continues to perform the action of "pulling in and starting" under the action of the electromagnetic force generated by the "follow current" current.

When t=t5, the "magnetic drive part" reaches the above-mentioned "set position", and this embodiment completes the suction process and enters the suction stage.

2. Holding:

In the time domain from t5 to t6, the transistor V1 is still in the off state, the voltage Vg on its collector is still "high level", and the field effect transistor FET in the pulse-controlled special-shaped bridge circuit 103 is still in the on state.

With the process of charging, the voltage on the second capacitor C2, that is, the voltage Vb between the base and the emitter of the triode V1 gradually rises, and when t=t6, Vb is equal to or greater than 0.7V, that is, Vb≥0.7V, so The above-mentioned triode V1 turns into a conduction state, and the voltage Vg on its collector becomes "low level", Vg≈0, and the field effect transistor FET in the pulse-controlled special-shaped bridge circuit 103 becomes a cut-off state, and the pull-in The current is turned off, that is, i1=0.

After the field effect transistor FET is turned off, the AC voltage provides "holding power" for the present invention through the control current i2 and the current i3 on the third capacitor C3.

As mentioned above, when t=t5, the "magnetic drive" has reached the "set position", and this embodiment has completed the "pulling-in process"; but in the time domain of t5-t6, the FET is still conducting, and The resultant current i1 still flows. In this t5-t6 time domain, the pull-in current i1 plays a role in consolidating the pull-in "results".

As mentioned above, starting at t=t6, the AC voltage provides "holding power" for this embodiment by controlling the current i2 and the current i3 on the third capacitor C3, and the process is as follows:

Combined with Figure 5, in the positive half cycle of the AC voltage where P1 is positive and P2 is negative: the control current i2 follows the previously mentioned P1-N1 terminal-AC1 terminal-D2-DC1 terminal-T1 terminal-A1-excitation coil L -A2-T2 terminal-DC2 terminal-1 terminal-C4-D4-2 terminal-(multiple paths such as R3)-N2 terminal-P2 path flows, and the AC voltage provides "holding power" through the control current i2.

In the negative half cycle of the AC voltage where P1 is negative and P2 is positive, the current i3 on the third capacitor C3 is along P2—N2 terminal—AC2 terminal—third capacitor C3—DC1 terminal—T1 terminal—A1—exciting coil L— The path of A2—T2 terminal—DC2 terminal—D1—AC1 terminal—N1 terminal—P1 flows through, and the AC voltage provides "holding power" through this current i3.

3. Reset

When t=t7, the AC voltage is turned off, and the current i in the excitation coil L follows the path A1—excitation coil L—A2—T2 terminal—DC2 terminal—D1—AC1 terminal—D2—DC1 terminal—T1 terminal—A1 path" continued flow" and gradually decreases to zero, this embodiment 1 resets.

At t=t8, the AC voltage is turned on again, and the embodiment 1 is turned on again, and re-enters the working cycle of "pulling in", "holding" and "resetting".

In summary, it can be seen that the pulse-controlled special-shaped bridge circuit 103 has two functions in the present invention, the first, the rectification function: the current rectification flowing into the exciting coil L becomes direct current; the second, the freewheeling function : Provide a "freewheeling" path for the current in the field coil L. In short: the pulse-controlled special-shaped bridge circuit 103 has two functions of rectification and freewheeling.

Fig. 6 is a schematic circuit diagram of Embodiment 2 of the present invention. The circuit structure of Embodiment 2 is the same as that of Embodiment 1, and the difference is: in Embodiment 2, "end 1" of the AC-DC conversion circuit 101 It is connected with the first output port T1.

The working principle and working process of this embodiment 2 are the same as those of embodiment 1.

The technical solution of the present invention has been described above, and all replacements that do not depart from the essence of the technical solution of the present invention should be within the scope of the claims of the present invention.

Claims (2)

1. A power-saving unit of an AC solenoid valve or an AC contactor, which is a four-port network consisting of a first input port, a second input port, a first output port, a second output port, a transient voltage suppression diode, an AC - Composed of DC conversion circuit, control pulse generating circuit, and pulse-controlled special-shaped bridge circuit; Wherein, the first input port is connected to the P1 end of the AC voltage, and the second input port is connected to the P2 end of the AC voltage; one end of the transient voltage suppression diode is connected to the first input port, and the other is connected to the P2 end of the AC voltage. One end is connected to the second input port; the first output port is connected to the A1 end of the excitation coil L, and the second output port is connected to the A2 end of the excitation coil L; the AC-DC conversion Terminal 1 of the circuit is also connected to the second output port; terminal 3 of the control pulse generating circuit is connected to terminal 2 of the AC-DC conversion circuit, terminal 4 is connected to terminal 5 of the pulse-controlled special-shaped bridge circuit connected; the AC1 end of the pulse-controlled special-shaped bridge circuit is connected to the first input port, the AC2 end is connected to the second input port, the DC1 end is connected to the first output port, and the DC2 end is connected to the second output port; Both the AC-DC conversion circuit and the control pulse generating circuit are provided with a port connected to the second input port; Wherein, the AC-DC conversion circuit is composed of a first capacitor, a fourth capacitor, a first resistor, a fourth diode, a fifth diode, 1 terminal, and 2 terminals; wherein, the fourth capacitor One end of one end is connected with said 1 end, and the other end is connected with the positive pole of the fourth diode and the negative pole of the fifth diode; the negative pole of the fourth diode, the positive pole of the first capacitor, the first resistor One end of each is connected to end 2; the positive pole of the fifth diode, the negative pole of the first capacitor, and the other end of the first resistor are all connected to the second input port; Wherein, the control pulse generating circuit is composed of a second resistor, a third resistor, a fourth resistor, a second capacitor, a triode V1, terminals 3 and 4; wherein, one terminal of the second resistor, the third resistor One end of the third resistor, one end of the fourth resistor, and one end of the second capacitor are all connected to the base of the triode; the other end of the second resistor and the collector of the triode are connected to the 4 The other end of the second capacitor, the other end of the fourth resistor, and the emitter of the triode are all connected to the second input port; Wherein, the pulse-controlled special-shaped bridge circuit consists of a first diode, a second diode, a third diode, a field effect transistor, a third capacitor, an AC1 terminal, an AC2 terminal, a DC1 terminal, a DC2 terminal, Composed of 5 terminals; wherein, the negative pole of the first diode and the positive pole of the second diode are connected to the AC1 terminal; the negative pole of the second diode and one end of the third capacitor are connected to the DC1 terminal; the third The anode of the diode and the anode of the first diode are connected to the DC2 terminal; the cathode of the third diode is connected to the drain of the field effect transistor; the grid of the effect transistor is connected to the 5 terminal; the third The other end of the capacitor and the source of the effect tube are both connected to the AC2 end. 2. The power-saving unit of an AC solenoid valve or an AC contactor as claimed in claim 1, characterized in that: The field effect transistor can be replaced by a unidirectional thyristor, a bidirectional thyristor, an insulated gate bipolar transistor, an electron injection enhanced gate transistor, an electrostatic induction thyristor or a switch triode.