CN218727571U - Alternating voltage's measuring circuit and smart machine - Google Patents
Alternating voltage's measuring circuit and smart machine Download PDFInfo
- Publication number
- CN218727571U CN218727571U CN202220953480.3U CN202220953480U CN218727571U CN 218727571 U CN218727571 U CN 218727571U CN 202220953480 U CN202220953480 U CN 202220953480U CN 218727571 U CN218727571 U CN 218727571U
- Authority
- CN
- China
- Prior art keywords
- voltage
- circuit
- resistor
- electrically connected
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The utility model discloses an alternating voltage's measuring circuit and smart machine, this alternating voltage's measuring circuit is through only setting up voltage comparison circuit before the opto-coupler circuit, so that external power supply's alternating voltage controls the break-make of opto-coupler circuit under voltage comparison circuit's the control of presetting reference voltage, and give level signal output for the controller, the controller is long when confirming switching on of opto-coupler circuit according to level signal again, need not with the help of complicated and expensive electronic components, only with the help of combining together of the software logic principle of simple circuit design and controller, also can confirm external alternating current power supply's alternating voltage value fast, the cost of measuring external alternating current power supply's alternating voltage value is reduced.
Description
Technical Field
The utility model relates to an alternating voltage measures technical field, especially relates to an alternating voltage's measuring circuit and smart machine.
Background
At present, the measurement schemes of ac voltage mainly include two main categories, wherein the first category is: the method comprises the following steps that a micro mutual inductor is used as a core element, an input high-voltage signal is directly converted into a low-voltage signal, or the input voltage is converted into a small-current signal through a primary series resistor of the mutual inductor, then the mutual inductor with the ratio of 1 to 1 is used for conversion, the converted current signal is converted into a voltage signal through resistance circuit processing, an alternating current signal output by the mutual inductor is processed through a proper operational amplifier circuit and then sent to an analog-to-digital conversion (ADC) chip for acquisition and conversion, a conversion result is sent to a Digital Signal Processing (DSP) chip for further algorithm processing, such as fast Fourier transform, and finally fundamental wave components and harmonic wave components of alternating current voltage can be obtained to obtain an effective value of the alternating current voltage; the second type is: the alternating current high voltage is converted into direct current low voltage in a mode of rectifying and then resistance voltage dividing, the direct current low voltage value is acquired and converted by an analog-to-digital conversion ADC (analog-to-digital converter) of the measurement chip, and then the effective value of the alternating current voltage is estimated by the measurement chip according to the average value of conversion results in a mode of fixing mathematical proportion.
However, the first category is found in practice because the mutual inductor itself is not cheap, and the digital processing of the alternating current signal requires an additional digital processing circuit and the processing flow is complex; in the second category, a voltage reduction and stabilization circuit for measuring power supply of the chip and an optical coupling isolation circuit for informing a main control chip of a measurement result are additionally arranged. It can be seen that the cost is relatively high for both the first and second types of measurement schemes.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that a measuring circuit of alternating voltage is provided, can determine external alternating current power supply's alternating voltage's magnitude of voltage fast, reduced the cost of measuring external alternating current power supply's alternating voltage's magnitude of voltage.
In order to solve the technical problem, a first aspect of the present invention discloses a measuring circuit for ac voltage, the measuring circuit includes an optical coupling circuit and a voltage comparison circuit, wherein the optical coupling circuit includes an optical coupling primary circuit and an optical coupling secondary circuit;
the output end of the voltage comparison circuit is electrically connected with the input end of the primary circuit of the optical coupler; the output end of the optical coupler primary circuit is connected with the input end of the optical coupler secondary circuit in an induction manner, and the output end of the optical coupler secondary circuit is electrically connected with a controller; the input end of the voltage comparison circuit is used for being electrically connected with an external alternating current power supply;
the voltage comparison circuit is used for providing reference voltage for measuring the alternating voltage of the external alternating current power supply and controlling the on-off of the primary circuit of the optical coupler;
the optical coupler primary circuit is used for outputting an optical electric signal under the control of the voltage comparison circuit;
the optical coupling secondary circuit is used for sensing the photoelectric signal, converting the photoelectric signal into a level signal and outputting the level signal to the controller so as to trigger the controller to determine the voltage value of the alternating voltage of the external alternating current power supply according to the duration of receiving the level signal.
As an optional implementation manner, in the first aspect of the present invention, the voltage comparison circuit includes a zener diode P or an adjustable voltage stabilizing circuit;
when the voltage comparison circuit is the adjustable voltage stabilizing circuit, the measuring circuit further comprises a voltage stabilizing power supply circuit;
the first output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the primary circuit of the optical coupler, the second output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the adjustable voltage-stabilizing circuit, and the input end of the voltage-stabilizing power supply circuit is used for being electrically connected with the external alternating-current power supply;
the voltage stabilizing power supply circuit is used for extracting an alternating voltage half wave from an alternating voltage wave of the external alternating current power supply and providing matched current for the primary circuit of the optical coupler.
As an optional implementation manner, in the first aspect of the present invention, the voltage stabilizing and supplying circuit includes a resistance-capacitance step-down voltage stabilizing circuit and a voltage extracting module;
the output end of the resistance-capacitance voltage-reducing and stabilizing circuit is electrically connected with the input end of the optocoupler primary circuit, the output end of the voltage extraction module is electrically connected with the input end of the resistance-capacitance voltage-reducing and stabilizing circuit and the input end of the voltage comparison circuit, and the input end of the voltage extraction module is used for being electrically connected with the external alternating current power supply;
the voltage extraction module is used for extracting an alternating voltage half wave from an alternating voltage wave of the external alternating current power supply;
and the resistance-capacitance voltage reduction and stabilization circuit is used for taking voltage from the extracted half-wave of the alternating voltage and providing current for the primary circuit of the optical coupler.
As an optional implementation manner, in the first aspect of the present invention, the measurement circuit further includes a transition edge processing circuit;
the input end of the hopping edge processing circuit is electrically connected with the output end of the optical coupling secondary circuit, and the output end of the hopping edge processing circuit is electrically connected with the controller;
and the transition edge processing circuit is used for changing the steepness of the rising edge of the level signal and the steepness of the falling edge of the level signal and transmitting the changed level signal to the controller.
As an optional implementation manner, in the first aspect of the present invention, the optical coupler primary circuit includes a first resistor R1, a second resistor R2, and a light emitting diode D1, and the optical coupler secondary circuit includes a phototransistor Q1 and a pull-up resistor R0; the first resistor R1 is connected with the light emitting diode D1 in parallel; the collector of the phototransistor Q1 is electrically connected with one end of the pull-up resistor R0, the base of the phototransistor Q1 is inductively connected with the light emitting diode D1, the emitter of the phototransistor Q1 is used for being connected with a secondary reference ground end, and the other end of the pull-up resistor R0 is electrically connected with an internal power supply V1;
when the voltage comparison circuit is the voltage regulator diode P, the cathode of the light emitting diode D1 is used for being electrically connected with the external alternating current power supply, one end of the second resistor R2 is electrically connected with the anode of the light emitting diode D1, the other end of the second resistor R2 is electrically connected with the anode of the voltage regulator diode P, and the cathode of the voltage regulator diode P is used for being electrically connected with the external alternating current power supply;
when the voltage comparison circuit is the adjustable voltage stabilizing circuit, the cathode of the light emitting diode D1 is electrically connected with the output end of the adjustable voltage stabilizing circuit; one end of the second resistor R2 is electrically connected with the anode of the light emitting diode D1, and the other end of the second resistor R2 is electrically connected with the output end of the voltage stabilizing power supply circuit.
As an optional implementation manner, in the first aspect of the present invention, the adjustable voltage stabilizing circuit includes a controllable voltage stabilizing source K, a third resistor R3, and a fourth resistor R4;
a cathode of the controllable voltage-stabilizing source K is electrically connected with the optocoupler circuit, a reference electrode of the controllable voltage-stabilizing source is electrically connected with a first end of the fourth resistor R4 and a first end of the third resistor R3 respectively, and a second end of the fourth resistor R4 is electrically connected with an input end of the voltage comparison circuit;
and the second end of the third resistor R3 and the anode of the controllable voltage-stabilizing source are both used for being connected with a primary reference ground end.
As an optional implementation manner, in the first aspect of the present invention, the resistance-capacitance voltage reduction and stabilization circuit includes a voltage regulator tube Z, a capacitor C, a fifth resistor R5, and a first diode D2;
one end of the fifth resistor R5 is electrically connected with the cathode of the first diode D2, the other end of the fifth resistor R5, one end of the capacitor C, the cathode of the voltage regulator tube Z and the other end of the second resistor R2 included by the primary circuit of the optical coupler are respectively electrically connected with a second internal power supply V2, and the anode of the first diode D2 is electrically connected with the output end of the voltage extraction module;
the other end of the capacitor C and the positive electrode of the voltage stabilizing tube Z are both used for being connected with a primary reference ground end.
As an optional implementation manner, in the first aspect of the present invention, the transition edge processing circuit includes a transistor Q2, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8;
one end of the sixth resistor R6 is electrically connected to an output end of the optocoupler circuit, the other end of the sixth resistor R6 is electrically connected to a base of the triode Q2 and one end of the seventh resistor R7, respectively, a collector of the triode Q2 is electrically connected to one end of the eighth resistor R8, one end of the eighth resistor R8 is electrically connected to the controller, and the other end of the eighth resistor R8 is electrically connected to the internal power supply V1;
the other end of the seventh resistor R7 and the emitter of the triode Q2 are both used for being connected with a secondary reference ground end.
As an optional implementation manner, in the first aspect of the present invention, the voltage extraction module includes a second diode D3;
the voltage extraction module further comprises a third diode D4, wherein the anode of the third diode D4 is used for being connected with a primary reference ground end, the cathode of the third diode D4 is used for being electrically connected with a zero line end of the external alternating current power supply, the anode of the second diode D3 is used for being electrically connected with a live wire end of the external alternating current power supply, and the cathode of the second diode D3 is electrically connected with the input end of the voltage comparison circuit.
The utility model discloses in a second aspect a smart machine, a serial communication port, smart machine includes any one kind in the first aspect alternating voltage's measuring circuit.
Implement the utility model discloses, following beneficial effect has:
the utility model discloses in, provide a measuring circuit of alternating voltage, this measuring circuit of alternating voltage includes opto-coupler circuit and voltage comparison circuit, wherein, this opto-coupler circuit includes opto-coupler primary circuit and opto-coupler secondary circuit; the output end of the voltage comparison circuit is electrically connected with the input end of the primary circuit of the optical coupler; the output end of the optical coupler primary circuit is inductively connected with the input end of the optical coupler secondary circuit, and the output end of the optical coupler secondary circuit is electrically connected with a controller; the input end of the voltage comparison circuit is used for being electrically connected with an external alternating current power supply; the voltage comparison circuit is used for providing reference voltage for measuring the alternating voltage of the external alternating current power supply and controlling the on-off of the primary circuit of the optical coupler; the optical coupler primary circuit is used for outputting an optical electric signal under the control of the voltage comparison circuit; and the optocoupler secondary circuit is used for sensing the photoelectric signal, converting the photoelectric signal into a level signal and outputting the level signal to the controller so as to trigger the controller to determine the voltage value of the alternating voltage of the external alternating current power supply according to the duration of the received level signal. It can be seen, the utility model discloses a only set up voltage comparison circuit before the opto-coupler circuit, so that external power supply's alternating current voltage controls the break-make of opto-coupler circuit under voltage comparison circuit's the control of presetting reference voltage, and give the controller with level signal output, the controller is long when confirming switching on of opto-coupler circuit according to level signal again, need not with the help of complicated and expensive electronic components, only with the help of simple circuit design and the software logical principle's of controller combination, also can confirm external alternating current power supply's alternating voltage value fast, the cost of measuring external alternating current power supply's alternating voltage value has been reduced.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an ac voltage measuring circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another ac voltage measuring circuit disclosed in the embodiment of the present invention;
fig. 3 is a schematic structural diagram of another alternative voltage measuring circuit disclosed in the embodiment of the present invention;
fig. 4 is a schematic structural diagram of another ac voltage measuring circuit disclosed in the embodiment of the present invention;
fig. 5 is a schematic structural diagram of an intelligent device disclosed in the embodiment of the present invention.
Detailed Description
For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
It is to be understood that, unless otherwise expressly specified or limited, the term "electrically connected" in the description and claims of the present invention and the above drawings is to be interpreted broadly, e.g., as meaning a fixed electrical connection, a removable electrical connection, or an integral electrical connection; can be mechanically and electrically connected, can be electrically connected or can be communicated with each other; either directly or indirectly through intervening media, either internally or in any other relationship. Furthermore, the terms "first," "second," and the like in the description and claims of the present invention and in the above-described drawings are used for distinguishing between different elements and not necessarily for describing a particular order, and the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusions. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
Example one
Referring to fig. 1, fig. 1 is a schematic structural diagram of a measurement circuit for ac voltage according to an embodiment of the present invention. As shown in fig. 1, the ac voltage measuring circuit includes an optical coupler circuit and a voltage comparison circuit, wherein the optical coupler circuit includes an optical coupler primary circuit and an optical coupler secondary circuit;
the output end of the voltage comparison circuit is electrically connected with the input end of the primary circuit of the optical coupler; the output end of the optical coupler primary circuit is inductively connected with the input end of the optical coupler secondary circuit, and the output end of the optical coupler secondary circuit is electrically connected with a controller; the input end of the voltage comparison circuit is used for being electrically connected with an external alternating current power supply; the voltage comparison circuit is used for providing reference voltage for measuring the alternating voltage of the external alternating current power supply and controlling the on-off of the primary circuit of the optical coupler; the optical coupler primary circuit is used for outputting an optical electric signal under the control of the voltage comparison circuit; and the optocoupler secondary circuit is used for sensing the photoelectric signal, converting the photoelectric signal into a level signal and outputting the level signal to the controller so as to trigger the controller to determine the voltage value of the alternating voltage of the external alternating current power supply according to the duration of the received level signal.
The embodiment of the utility model provides an in, it is concrete, the controller calculates the duration of received level signal through the counter that obtains from the high-speed oscillator in area and frequency divider, determines that the time of switching on of opto-coupler secondary circuit is long, and then calculates external AC power supply's alternating voltage's magnitude of voltage.
It can be seen, the utility model discloses a only set up voltage comparison circuit before the opto-coupler circuit, so that external power supply's alternating current voltage controls the break-make of opto-coupler circuit under voltage comparison circuit's the control of presetting reference voltage, and give the controller with level signal output, the controller is long when confirming switching on of opto-coupler circuit according to level signal again, need not with the help of complicated and expensive electronic components, only with the help of simple circuit design and the software logical principle's of controller combination, also can confirm external alternating current power supply's alternating voltage value fast, the cost of measuring external alternating current power supply's alternating voltage value has been reduced.
In the embodiment of the present invention, as shown in fig. 3 or 4, the optical coupler primary circuit includes a first resistor R1, a second resistor R2, and a light emitting diode D1, and the optical coupler secondary circuit includes a phototransistor Q1 and a pull-up resistor R0; the first resistor R1 is connected with the light emitting diode D1 in parallel; the collector of the phototransistor Q1 is electrically connected with one end of a pull-up resistor R0, the base of the phototransistor Q1 is inductively connected with a light-emitting diode D1, the emitter of the phototransistor Q1 is used for being connected with a secondary reference ground end, and the other end of the pull-up resistor R0 is electrically connected with an internal power supply V1. Optionally, the combination of the light emitting diode D1 and the phototransistor Q1 may be EL817 or EL357 as a core component of the optical coupling circuit, so that the cost can be reduced. Furthermore, by setting a preset reference voltage of the measuring circuit, for example, 83.7V, and because the switching time of the optocoupler transistor Q1 is fixed after the components of the optocoupler circuit are selected, the lower the preset reference voltage value is under the same ac voltage, the longer the on-time of the optocoupler is, which means that the influence of the on-time of the optocoupler on the secondary switching time is smaller, and the higher the measurement accuracy of the ac voltage is.
In the embodiment of the utility model provides an in, in order to ensure measurement accuracy, to opto-coupler secondary circuit, can confirm the resistance value of the pull-up resistance R0 who connects opto-coupler phototransistor Q1's collecting electrode according to the phototransistor Q1 and the specific model of emitting diode D1 of chooseing for use. Generally, the smaller the value of the pull-up resistor R0 is, the less easily the phototransistor Q1 of the optocoupler secondary circuit enters saturation, the longer the time from off to on, and the shorter the time from on to off, generally, the difference between the time from off to on of the phototransistor Q1 and the time from on to off of the phototransistor Q1 can be shortened by reducing the resistance value of the pull-up resistor R0, but curves of different optocoupler types, which change with the change of the resistance value of the pull-up resistor R0, of the time from off to on and the time from on to off, are different, and the too small resistance value of the pull-up resistor R0 affects the voltage difference between the collector and the emitter of the phototransistor Q1 during the on of the optocoupler, and further affects the judgment of the controller on the high and low level signals, so the pull-up resistor R0 with a proper resistance value (e.g., 8.2k Ω) needs to be selected. For example: the actual electrifying time of the light emitting diode D1 of the optical coupler is 8000us, time delay exists when electricity is converted into light waves, time delay also exists when the light waves are converted into electrons, the conducting time of the phototransistor Q1 of the optical coupler detected by the controller can be 8010us, and therefore a measuring error of more than 1V can be introduced.
In an alternative embodiment, as shown in FIG. 2, the measurement circuit further includes a transition edge processing circuit; the input end of the hopping edge processing circuit is electrically connected with the output end of the optical coupler secondary circuit, and the output end of the hopping edge processing circuit is electrically connected with the controller; and the transition edge processing circuit is used for changing the steepness of the rising edge of the level signal and the steepness of the falling edge of the level signal and transmitting the changed level signal to the controller. Therefore, the rising edge and the falling edge of the level signal input into the controller become steep through the jump edge processing circuit, different controllers can stably identify the level jump moment, and therefore the measurement accuracy and efficiency of the alternating voltage are improved.
In this optional embodiment, as shown in fig. 3 or 4, optionally, the transition edge processing circuit includes a transistor Q2, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8; one end of a sixth resistor R6 is electrically connected with the output end of the optocoupler circuit, the other end of the sixth resistor R6 is electrically connected with the base of the triode Q2 and one end of a seventh resistor R7 respectively, the collector of the triode Q2 is electrically connected with one end of an eighth resistor R8, one end of the eighth resistor R8 is electrically connected with the controller, and the other end of the eighth resistor R8 is electrically connected with an internal power supply V1; the other end of the seventh resistor R7 and the emitter of the triode Q2 are both used for being connected with the secondary reference ground end.
In this alternative embodiment, in order to ensure the measurement accuracy, the transition timing of the level signal input to the controller is changed by the transition edge processing circuit, thereby reducing the difference between the time period during which the ordinary optocoupler phototransistor Q is turned on from off and the time period during which the phototransistor Q is turned back off from on. For example, the voltage at the collector of the phototransistor Q1 of the optocoupler secondary circuit continuously drops during the time period when the phototransistor Q1 goes from off to on, and typically, when the controller detects that the voltage at the collector of the phototransistor Q1 drops below 1.5V, the controller recognizes the switching of the input signal from high to low, and may recognize the transition edge by the transition edge processing circuit when the voltage at the collector of the phototransistor Q1 drops below 1.2V, which is equivalent to the extension of the time period when the phototransistor Q1 goes from off to on, and similarly, the voltage at the collector of the phototransistor Q1 continuously rises during the time period from on back to off, and typically, when the controller detects that the voltage at the collector of the phototransistor Q1 rises above 3.5V, the controller recognizes the switching of the input signal from low to high, and may recognize the transition edge by the transition edge processing circuit when the voltage at the collector of the phototransistor Q1 rises to 3.2V, which is equivalent to the switching of the off back to on of the phototransistor Q1, and thus, the voltage at the time period from the transition of the collector of the phototransistor Q1 to on back to the off is equivalent to the on, and the time period from the phototransistor Q1 to the on, the transition is shortened from the normal time period to the on, and the time period of the phototransistor Q1. For example, the triode Q2 in the transition edge processing circuit may use a simple triode circuit, a triode with a voltage difference between a base voltage and an emitter voltage of 0.6V is selected as a core element, and a pull-down resistor R7 of 10k ohms is selected, when the base resistor R6 of the triode Q2 is 10k ohms, the triode Q2 with an input level greater than 1.2V is turned on, that is, when the phototransistor Q1 is turned on from off, the voltage of the collector of the phototransistor Q1 drops below 1.2V from 5V, the triode Q2 is turned off, when the phototransistor Q is turned on back to off, the voltage of the collector of the phototransistor Q1 rises above 1.2V from 0V, the triode Q2 is turned on, and the off time of the triode Q2 corresponds to the power-on time of the optocoupler light emitting diode D1.
It should be noted that, the TLP2301 of TOSHIBA may be selected as a core element of the optocoupler circuit for the combination of the light emitting diode D1 and the phototransistor Q1, so that the measurement accuracy of the alternating voltage can be further improved.
In the embodiment of the present invention, optionally, the voltage comparison circuit includes a zener diode P or an adjustable voltage stabilizing circuit. When the voltage comparison circuit is an adjustable voltage stabilizing circuit, the measuring circuit also comprises a voltage stabilizing power supply circuit; the first output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the optocoupler primary circuit, the second output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the adjustable voltage stabilizing circuit, and the input end of the voltage-stabilizing power supply circuit is used for being electrically connected with an external alternating current power supply; the voltage stabilizing power supply circuit is used for extracting an alternating voltage half wave from an alternating voltage wave of an external alternating current power supply and providing matched current for the primary circuit of the optical coupler.
In the embodiment of the present invention, optionally, the voltage-stabilizing power supply circuit includes a resistance-capacitance voltage-reducing and stabilizing circuit and a voltage extraction module; the output end of the voltage extraction module is electrically connected with the input end of the resistance-capacitance voltage reduction and stabilizing circuit and the input end of the voltage comparison circuit, and the input end of the voltage extraction module is electrically connected with an external alternating current power supply; the voltage extraction module is used for extracting an alternating voltage half wave (such as 0-180 degrees) from an alternating voltage wave of an external alternating current power supply; and the resistance-capacitance voltage reduction and stabilization circuit is used for taking voltage from the extracted half-wave of the alternating voltage and providing current for the primary circuit of the optical coupler. As shown in fig. 4, optionally, the resistance-capacitance voltage reduction and stabilization circuit includes a voltage regulator tube Z, a capacitor C, a fifth resistor R5, and a first diode D2; one end of a fifth resistor R5 is electrically connected with the cathode of the first diode D2, the other end of the fifth resistor R5, one end of the capacitor C, the cathode of the voltage regulator tube Z and the other end of the second resistor R2 included by the primary circuit of the optical coupler are electrically connected with a second internal power supply V2 respectively, and the anode of the first diode D2 is electrically connected with the output end of the voltage extraction module; the other end of the capacitor C and the positive electrode of the voltage-stabilizing tube Z are both used for being connected with a primary reference ground end. The voltage extracted by the resistance-capacitance voltage reduction and stabilizing circuit is a voltage in a preset voltage range, such as: 6.8V between 6.0V and 7.0V can reduce the occurrence of circuit heating caused by overlarge extracted voltage, and find a voltage stabilizing tube Z which can meet the requirement of different working currents and voltages and keep stable, thereby improving the universal applicability of the circuit. And the current provided by the resistance-capacitance voltage reduction and stabilization circuit to the rear-stage optical coupler primary circuit is the current within a preset current range, such as: 0.8mA-1.2mA, so that the cost of the resistance-capacitance voltage reduction and stabilization circuit can be reduced, the heating of elements can be reduced, the standby power consumption can be reduced, and the applicability of the circuit can be improved; the influence on the normal work of the voltage comparison circuit and the switching time of the level signal of the optical coupling secondary circuit can be reduced, and the measurement accuracy of the alternating voltage is further improved. It should be noted that the resistance-capacitance voltage reduction and stabilization circuit can be replaced by a switching power supply circuit.
When the voltage comparison circuit is a voltage regulator diode P, as shown in fig. 3, a negative electrode of the light emitting diode D1 is used for being electrically connected to an external ac power supply, one end of the second resistor R2 is electrically connected to an anode of the light emitting diode D1, the other end of the second resistor R2 is electrically connected to an anode of the voltage regulator diode P, and a negative electrode of the voltage regulator diode P is used for being electrically connected to the external ac power supply; therefore, the current flowing through the voltage stabilizing diode P is controlled by the second resistor R2, and the situation that the voltage stabilizing diode P is burnt out due to overheating and the alternating voltage of the external alternating current power supply cannot be measured can be reduced. The second resistor R2 may be a single resistor, or may be composed of a plurality of resistors having equal or unequal resistance values. Further, as shown in fig. 3, the measurement circuit for the ac voltage further includes a third diode D4, and the third diode D4 is disposed between the first resistor R1 and the external ac power supply, so that by disposing the third diode D4, the current flowing through the second resistor R2 and the first resistor R1 can be cut off during the ac negative half-wave, the heat generation of the second resistor R2 and the first resistor R1 can be reduced, and the light emitting diode D1 of the optical coupler can be protected.
When the voltage comparison circuit is an adjustable voltage stabilizing circuit, as shown in fig. 4, the cathode of the light emitting diode D1 is electrically connected with the output end of the adjustable voltage stabilizing circuit; one end of the second resistor R2 is electrically connected with the anode of the light emitting diode D1, and the other end of the second resistor R2 is electrically connected with the output end of the voltage-stabilizing power supply circuit. The adjustable voltage stabilizing circuit comprises a controllable voltage stabilizing source K, a third resistor R3 and a fourth resistor R4; the cathode of the controllable voltage-stabilizing source K is electrically connected with the optocoupler circuit, the reference electrode of the controllable voltage-stabilizing source is respectively electrically connected with the first end of the fourth resistor R4 and the first end of the third resistor R3, and the second end of the fourth resistor R4 is electrically connected with the input end of the voltage comparison circuit; the second end of the third resistor R3 and the anode of the controllable voltage-stabilizing source are both used for being connected with the secondary reference ground end. The utility model provides a predetermine reference voltage can be confirmed through controllable steady voltage source K, third resistance R3 and fourth resistance R4. The controllable voltage-stabilizing source K may include a TL431 voltage stabilizer or a comparator chip. And, as shown in fig. 4, the voltage extraction module includes a second diode D3; the voltage extraction module further comprises a third diode D4, wherein the anode of the third diode D4 is used for being connected with the primary reference ground end, the cathode of the third diode D4 is used for being electrically connected with the zero line end of the external alternating current power supply, the anode of the second diode D3 is used for being electrically connected with the live wire end of the external alternating current power supply, and the cathode of the second diode D3 is electrically connected with the input end of the voltage comparison circuit. By adding the third diode D4, the phenomenon that when reverse surge voltage occurs, the second diode D3 is broken down to cause the second diode D3 to be in an open-circuit state, so that the circuit cannot measure the alternating voltage, or the second diode D3 is in a short-circuit state, so that the circuit cannot cut off current flowing through the fourth resistor R4 and the third resistor R3 during negative half-wave, further the heating of the fourth resistor R4 and the third resistor R3 is increased, and the occurrence condition that the controllable voltage stabilizing source K is easily damaged is caused is reduced, the anti-surge capacity of the measuring circuit of the alternating voltage is improved, and the effect of protecting the measuring circuit is achieved.
The embodiment of the utility model provides an in, it is optional, when the electric control equipment that alternating voltage's measuring circuit corresponds is from taking switching power supply, the voltage draws the module and can be the rectifier bridge, and this moment, and the low voltage DC power supply of the bias winding output of switching power supply's transformer can replace resistance-capacitance step-down voltage stabilizing circuit, can further reduce measuring circuit's cost like this.
The embodiment of the utility model provides a explain alternating voltage's measuring circuit's theory of operation with figure 4:
the embodiment of the utility model provides a, when external AC power supply was gone up the electricity, AC voltage's measuring circuit began to work, and when external AC power supply's instantaneous voltage was 0V, second diode D3 and third diode D4 were in the off-state, did not have electric current to flow through fourth resistance R4 and third resistance R3, and at this moment, controllable steady voltage source K consults utmost pointThe voltage is 0V and is less than the reference voltage (such as 2.5V) in the controllable voltage-stabilizing source K, and the controllable voltage-stabilizing source K is in a cut-off state; when the instantaneous voltage of the external alternating current power supply is greater than the sum of the conduction voltages of the second diode D3 and the third diode D4 (for example, 1.4V), the second diode D3 and the third diode D4 are in a conduction state, at this time, current flows through the fourth resistor R4 and the third resistor R3, so that a voltage drop is formed on the third resistor R3, and the difference between the voltage drop formed on the third resistor R3 and the sum of the instantaneous voltage of the external alternating current power supply and the conduction voltages of the second diode D3 and the third diode D4 is in a fixed positive proportional relationship. Therefore, the voltage drop formed across the third resistor R3 increases with the increase of the instantaneous voltage of the external ac power supply and decreases with the decrease of the instantaneous voltage of the external ac power supply. At this time, if the voltage drop formed on the third resistor R3 is smaller than the reference voltage inside the controllable voltage regulator K, that is, when the instantaneous voltage of the external ac power supply is smaller than the preset comparison voltage, the controllable voltage regulator K is still in a cut-off state, the primary circuit of the optocoupler is in a cut-off state, the light emitting diode D1 does not emit light, the phototransistor Q1 is in a cut-off state, at this time, the triode Q2 is in a conduction state under the power supply of the internal power supply V1, the voltage of the collector of the triode Q2 is pulled down to 0V, and the voltage signal flowing into the controller is a low level signal; when the voltage drop formed on the third resistor R3 is greater than the reference voltage inside the controllable voltage-stabilizing source K, that is, the instantaneous voltage of the external ac power supply is greater than the preset comparison voltage, the voltage of the reference electrode of the controllable voltage-stabilizing source K is greater than or equal to the reference voltage inside the controllable voltage-stabilizing source K, the controllable voltage-stabilizing source K is in a conducting state, the primary circuit of the optocoupler is switched on, when the voltage at the two ends of the light-emitting diode D1 is greater than or equal to the conducting voltage thereof, the light-emitting diode D1 emits light, and the phototransistor Q1 is in a conducting state. At this time, the voltage of the base of the transistor Q2 is pulled down to 0V by the phototransistor Q1, the transistor Q2 is in a cut-off state, the voltage of the collector of the transistor Q2 is pulled up by the internal power supply V1, and at this time, the voltage signal flowing into the controller is a high level signal. And because the instantaneous voltage waveform of the external AC power supply changes in a sine wave rule, the AC voltage in each period changes along with the timeDuring the wave period, the voltage signal flowing into the controller has a continuous high level period, and during each period of the alternating current voltage wave, along with the increase of the instantaneous voltage of the external alternating current power supply from 0V, when the effective voltage value of the external alternating current power supply is higher, the voltage drop formed on the third resistor R3 is faster to rise to the reference voltage value inside the controllable voltage stabilization source K, and along with the decrease of the instantaneous voltage of the external alternating current power supply from the peak value, when the effective voltage value of the external alternating current power supply is higher, the speed of the voltage drop formed on the third resistor R3 to the reference voltage value inside the controllable voltage stabilization source K is slower, so that the high level period of the voltage signal flowing into the controller is lengthened along with the increase of the effective voltage value of the external alternating current power supply, and is shortened along with the decrease of the effective voltage value of the external alternating current power supply. At this time, when the effective voltage value of the external ac power supply is known, the time length required for the instantaneous voltage of the external ac power supply to rise from 0V to the preset comparison voltage, or vice versa, can be obtained through the sine function y = a sin (x), where y is the preset comparison voltage value, and a is the effective voltage value of the external ac power supply
And x is an arc value corresponding to a time period T1 required by the instantaneous voltage of the external alternating current power supply to rise from 0V to a preset comparison voltage, and the arc value x =2 × pi × T1/T, wherein T is a periodic value of the waveform of the external alternating current power supply voltage, for example, T is 20ms, and the high-level time period T2= T/2-2 × T1. Therefore, the controller can quickly determine the alternating voltage value of the external alternating current power supply by capturing the duration of the high level of the input voltage signal, without the aid of complex and expensive electronic components and by the aid of combination of simple circuit design and the software logic principle of the controller, and the cost of measuring the alternating voltage value of the external alternating current power supply is reduced.
Example two
The embodiment of the utility model discloses a smart machine, figure 5 discloses a smart machine's schematic structure diagram, and this smart machine includes like embodiment one's alternating voltage's measuring circuit for the equipment that needs to measure alternating voltage and this smart machine. It should be noted that, for the detailed description of the measurement circuit of the ac voltage, please refer to the detailed description of the related contents in the embodiment, which is not repeated in this embodiment.
It can be seen that, in the intelligent device described in fig. 5, only the voltage comparison circuit is arranged in front of the optical coupler circuit, so that the ac voltage of the external power supply is controlled to be on or off by the preset reference voltage of the voltage comparison circuit, and the level signal is output to the controller, and the controller determines the duration of the on state of the optical coupler circuit according to the level signal, without using complex and expensive electronic components, and only by combining simple circuit design and the software logic principle of the controller, the voltage value of the ac voltage of the external ac power supply can be quickly determined, and the cost for measuring the voltage value of the ac voltage of the external ac power supply is reduced.
The above detailed description is made on the measurement circuit and the intelligent device of the ac voltage disclosed in the embodiments of the present invention, and the principle and the implementation of the present invention are explained by applying the specific embodiments herein, but the above preferred embodiments are not intended to limit the present invention, and the description of the above embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for those skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and applications without departing from the spirit and scope of the present invention, and therefore, the scope of the present invention is subject to the scope defined by the claims.
Claims (10)
1. The measuring circuit of the alternating voltage is characterized by comprising an optical coupler circuit and a voltage comparison circuit, wherein the optical coupler circuit comprises an optical coupler primary circuit and an optical coupler secondary circuit;
the output end of the voltage comparison circuit is electrically connected with the input end of the primary circuit of the optical coupler; the output end of the optical coupler primary circuit is inductively connected with the input end of the optical coupler secondary circuit, and the output end of the optical coupler secondary circuit is electrically connected with a controller; the input end of the voltage comparison circuit is used for being electrically connected with an external alternating current power supply;
the voltage comparison circuit is used for providing reference voltage for measuring the alternating voltage of the external alternating current power supply and controlling the on-off of the primary circuit of the optical coupler;
the optical coupler primary circuit is used for outputting an optical signal under the control of the voltage comparison circuit;
the optical coupling secondary circuit is used for sensing the photoelectric signal, converting the photoelectric signal into a level signal and outputting the level signal to the controller so as to trigger the controller to determine the voltage value of the alternating voltage of the external alternating current power supply according to the duration of receiving the level signal.
2. The alternating voltage measuring circuit according to claim 1, characterized in that said voltage comparison circuit comprises a zener diode (P) or an adjustable voltage regulation circuit;
when the voltage comparison circuit is the adjustable voltage stabilizing circuit, the measuring circuit further comprises a voltage stabilizing power supply circuit;
the first output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the optocoupler primary circuit, the second output end of the voltage-stabilizing power supply circuit is electrically connected with the input end of the adjustable voltage stabilizing circuit, and the input end of the voltage-stabilizing power supply circuit is used for being electrically connected with the external alternating current power supply;
and the voltage-stabilizing power supply circuit is used for extracting an alternating voltage half wave from an alternating voltage wave of the external alternating current power supply and providing matched current for the primary circuit of the optical coupler.
3. The alternating voltage measuring circuit according to claim 2, wherein the voltage stabilizing and supplying circuit comprises a resistance-capacitance voltage reducing and stabilizing circuit and a voltage extracting module;
the output end of the resistance-capacitance voltage reduction and stabilization circuit is electrically connected with the input end of the optical coupler primary circuit, the output end of the voltage extraction module is electrically connected with the input end of the resistance-capacitance voltage reduction and stabilization circuit and the input end of the voltage comparison circuit, and the input end of the voltage extraction module is used for being electrically connected with the external alternating current power supply;
the voltage extraction module is used for extracting an alternating voltage half wave from an alternating voltage wave of the external alternating current power supply;
and the resistance-capacitance voltage reduction and stabilization circuit is used for taking voltage from the extracted half-wave of the alternating voltage and providing current for the primary circuit of the optical coupler.
4. An alternating voltage measuring circuit according to any of claims 1-3, characterized in that the measuring circuit further comprises a transition edge processing circuit;
the input end of the hopping edge processing circuit is electrically connected with the output end of the optical coupling secondary circuit, and the output end of the hopping edge processing circuit is electrically connected with the controller;
and the transition edge processing circuit is used for changing the steepness of the rising edge of the level signal and the steepness of the falling edge of the level signal and transmitting the changed level signal to the controller.
5. An alternating voltage measuring circuit according to claim 2 or 3, characterized in that the optocoupler primary circuit comprises a first resistor (R1), a second resistor (R2) and a light emitting diode (D1), and the optocoupler secondary circuit comprises a phototransistor (Q1) and a pull-up resistor (R0); wherein the first resistor (R1) is connected in parallel with the light emitting diode (D1); the collector of the phototransistor (Q1) is electrically connected with one end of the pull-up resistor (R0), the base of the phototransistor (Q1) is inductively connected with the light-emitting diode (D1), the emitter of the phototransistor (Q1) is used for being connected with a secondary reference ground end, and the other end of the pull-up resistor (R0) is electrically connected with an internal power supply (V1);
when the voltage comparison circuit is the voltage stabilizing diode (P), the negative electrode of the light emitting diode (D1) is used for being electrically connected with the external alternating current power supply, one end of the second resistor (R2) is electrically connected with the positive electrode of the light emitting diode (D1), the other end of the second resistor (R2) is electrically connected with the positive electrode of the voltage stabilizing diode (P), and the negative electrode of the voltage stabilizing diode (P) is used for being electrically connected with the external alternating current power supply;
when the voltage comparison circuit is the adjustable voltage stabilizing circuit, the cathode of the light emitting diode (D1) is electrically connected with the output end of the adjustable voltage stabilizing circuit; one end of the second resistor (R2) is electrically connected with the positive electrode of the light-emitting diode (D1), and the other end of the second resistor (R2) is electrically connected with the output end of the voltage-stabilizing power supply circuit.
6. An alternating voltage measuring circuit according to claim 2 or 3, characterized in that said adjustable voltage regulation circuit comprises a controllable regulator supply (K), a third resistor (R3) and a fourth resistor (R4);
the cathode of the controllable voltage-stabilizing source (K) is electrically connected with the optocoupler circuit, the reference electrode of the controllable voltage-stabilizing source is electrically connected with the first end of the fourth resistor (R4) and the first end of the third resistor (R3) respectively, and the second end of the fourth resistor (R4) is electrically connected with the input end of the voltage comparison circuit;
and the second end of the third resistor (R3) and the anode of the controllable voltage stabilizing source are both used for being connected with a primary reference ground end.
7. A circuit for measuring an alternating voltage according to claim 3, characterized in that said resistor-capacitor voltage-reducing regulator circuit comprises a zener diode (Z), a capacitor (C), a fifth resistor (R5) and a first diode (D2);
one end of the fifth resistor (R5) is electrically connected with the cathode of the first diode (D2), the other end of the fifth resistor (R5), one end of the capacitor (C), the cathode of the voltage-stabilizing tube (Z) and the other end of the second resistor (R2) included by the optocoupler primary circuit are respectively electrically connected with a second internal power supply (V2), and the anode of the first diode (D2) is electrically connected with the output end of the voltage extraction module;
the other end of the capacitor (C) and the positive electrode of the voltage stabilizing tube (Z) are both used for being connected with a primary reference ground end.
8. The alternating voltage measuring circuit according to claim 4, wherein the transition edge processing circuit comprises a transistor (Q2), a sixth resistor (R6), a seventh resistor (R7) and an eighth resistor (R8);
one end of the sixth resistor (R6) is electrically connected with the output end of the optocoupler circuit, the other end of the sixth resistor (R6) is electrically connected with the base of the triode (Q2) and one end of the seventh resistor (R7) respectively, the collector of the triode (Q2) is electrically connected with one end of the eighth resistor (R8), one end of the eighth resistor (R8) is used for being electrically connected with the controller, and the other end of the eighth resistor (R8) is used for being electrically connected with an internal power supply (V1);
the other end of the seventh resistor (R7) and the emitter of the triode (Q2) are both used for being connected with a secondary reference ground end.
9. An alternating voltage measuring circuit according to claim 3, characterized in that said voltage extraction module comprises a second diode (D3);
the voltage extraction module further comprises a third diode (D4), wherein the anode of the third diode (D4) is used for connecting a primary reference ground end, the cathode of the third diode (D4) is used for electrically connecting a zero line end of an external alternating current power supply, the anode of the second diode (D3) is used for electrically connecting a live wire end of the external alternating current power supply, and the cathode of the second diode (D3) is electrically connected with the input end of the voltage comparison circuit.
10. A smart device, characterized in that it comprises a measuring circuit of an alternating voltage according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220953480.3U CN218727571U (en) | 2022-04-22 | 2022-04-22 | Alternating voltage's measuring circuit and smart machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220953480.3U CN218727571U (en) | 2022-04-22 | 2022-04-22 | Alternating voltage's measuring circuit and smart machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218727571U true CN218727571U (en) | 2023-03-24 |
Family
ID=85582193
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220953480.3U Active CN218727571U (en) | 2022-04-22 | 2022-04-22 | Alternating voltage's measuring circuit and smart machine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218727571U (en) |
-
2022
- 2022-04-22 CN CN202220953480.3U patent/CN218727571U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101552560B (en) | Switch voltage stabilizing circuit and control method thereof | |
| US8953347B2 (en) | Capacitor discharging circuit and power converter | |
| CN202025037U (en) | Zero crossing detecting circuit | |
| CN103701327A (en) | Off-line power converter and integrated circuit suitable for use in same | |
| TWI590574B (en) | Power supply apparatus | |
| CN105991035A (en) | Flyback-based power conversion device | |
| EP0687050A2 (en) | An overcurrent protection apparatus | |
| EP3484035A1 (en) | Hysteresis power supply circuit | |
| TWI646767B (en) | Power control device and power control system | |
| CN105245112A (en) | Self-adaptive high-precision constant current circuit and switching power supply | |
| RU2618002C2 (en) | Protection circuit from voltage swell and power saving for switched power supply | |
| CN112787513B (en) | Flyback power converter and active clamping buffer thereof | |
| CN210894489U (en) | Zero-crossing detection circuit | |
| CN218727571U (en) | Alternating voltage's measuring circuit and smart machine | |
| CN116436305A (en) | Secondary side controlled QR flyback converter using programmable valley algorithm | |
| CN114859100A (en) | Measuring circuit and measuring method of alternating voltage and intelligent equipment | |
| CN113014125B (en) | Power supply device and operation method thereof | |
| CN210129019U (en) | Flash switch control system and input flash detection circuit thereof | |
| CN107425741B (en) | AC-DC conversion circuit with low-voltage protection | |
| CN219145272U (en) | Input voltage regulating circuit | |
| CN216794870U (en) | Switching power supply circuit | |
| CN219268736U (en) | Input voltage regulating circuit | |
| CN219268735U (en) | Input voltage regulating circuit | |
| CN217112490U (en) | Commercial power voltage detection circuit | |
| CN215378777U (en) | Switching power supply circuit and switching power supply system using same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |