Aerial detection digital signal acquisition circuit with voltage threshold control

Abstract

The utility model belongs to the technical field of digital quantity signal acquisition circuits, and particularly relates to an acquisition circuit with voltage threshold control for aviation detection of digital quantity signals. The acquisition circuit comprises a plurality of voltage stabilizing diodes, a resistor R1, a resistor R2, a capacitor C1 and an optocoupler module D1, wherein the voltage stabilizing diodes are sequentially connected in series. The voltage stabilizing diode at the output end is connected with the optocoupler module D1 through a resistor R1, a capacitor C1 is arranged between the resistor R1 and the optocoupler module D1 in parallel, and the resistor R1 and the capacitor C1 form an RC filter circuit; the first output end of the optical coupling module D1 is connected with a power supply voltage VCC through a resistor R2, and the second output end of the optical coupling module D1 is connected with a digital ground DGND. The digital quantity acquisition circuit can set more accurate threshold voltage for digital quantity acquisition, and has better practicability.

Description

Technical Field

[0001] The utility model belongs to the technical field of digital signal acquisition circuits, and in particular relates to an acquisition circuit with voltage threshold control for aviation detection of digital signals. Background Art

[0002] In digital signal acquisition, the collected digital signals need to be isolated and processed. This is often achieved using an optocoupler module. When the input signal is high, the optocoupler module conducts, and the output terminal is connected to the digital ground DGND, outputting a low level. When the input signal is low, the optocoupler module is not conducting, and the output terminal is pulled up to VCC through resistor R, outputting a high level, thus achieving signal isolation, level conversion, and other functions. However, when the input signal voltage is greater than the optocoupler module's conduction voltage, the optocoupler module conducts, and the output is low.

[0003] In actual use, it is often necessary to accurately detect the voltage of the input signal. For example, in the detection of aviation products, it is often necessary to collect the DC 28V / open digital signal output by the product. The threshold voltage of the signal is generally DC 24V. If the above circuit is used for collection, the signal quality of the product output cannot be fully detected, posing a major safety hazard. Utility Model Content

[0004] The purpose of the utility model is to provide an acquisition circuit with voltage threshold control for detecting digital signals in aviation, aiming to solve the above-mentioned problems.

[0005] The utility model is mainly realized through the following technical solutions:

[0006] A collection circuit with voltage threshold control for detecting digital signals in aviation, comprising a plurality of voltage-stabilizing diodes, a resistor R1, a resistor R2, a capacitor C1, and an optocoupler module D1 connected in series. The voltage-stabilizing diode at the output end is connected to the optocoupler module D1 via the resistor R1, a capacitor C1 is provided in parallel between the resistor R1 and the optocoupler module D1, and the resistor R1 and the capacitor C1 form an RC filter circuit for filtering out input signal jitter and high-frequency interference. The first output end of the optocoupler module D1 is connected to a power supply voltage VCC via the resistor R2, and the second output end of the optocoupler module D1 is connected to a digital ground DGND. The voltage of the input digital signal is V in ; The regulated voltage of several zener diodes connected in series is V1; the on-state voltage drop of the optocoupler module D1 is V2, and the minimum driving current is I1; the threshold voltage value of the acquisition circuit is V1+V2+I1*R1; the model of the zener diode is IN4747, the resistor R1 and the resistor R2 are metal film resistors respectively, and the model of the optocoupler module D1 is EL357N.

[0007] In order to better implement the present utility model, further, the zener diode at the output end is connected to one end of the light-emitting diode of the optocoupler module D1 through a resistor R1, and the other ends of the capacitor C1 and the light-emitting diode of the optocoupler module D1 are both grounded.

[0008] In order to better implement the present utility model, further, the regulated voltage V1 of several serially connected zener diodes in sequence is 20V, the conduction voltage drop V2 of the optocoupler module D1 is 1.2V, and the minimum drive current is I1 = 1mA; the resistance value of the resistor R1 is 2.7KΩ, and the capacitance value of the capacitor C1 is 1uF; the threshold voltage value of the acquisition circuit is 23.9V.

[0009] In order to better implement the present utility model, further, the resistance value of the resistor R2 is 10KΩ, and the power supply voltage VCC is DC 5V.

[0010] In order to better implement the present utility model, further, when V in < V1, the zener diode is not conducting, the optocoupler module D1 is not conducting, and the output of the acquisition circuit is at a high level.

[0011] In order to better implement the present utility model, further, when V1 < V in [[ID=十六]]< V1 + V2, the zener diode is conducting, the voltage drop of the zener diode is equal to V1, the optocoupler module D1 is not conducting, and the output of the acquisition circuit is at a high level.

[0012] In order to better implement the present utility model, further, when V1 + V2 < V in < V1 + V2 + I1 * R1, the zener diode is conducting, the optocoupler module D1 is not conducting, and the output of the acquisition circuit is at a high level.

[0013] In order to better implement the present utility model, further, when V in ≥ V1 + V2 + I1 * R1, the zener diode is conducting, the optocoupler module D1 is conducting, and the output of the acquisition circuit is at a low level.

[0014] The beneficial effects of the present utility model are as follows:

[0015] When the present utility model is in use, when the input signal voltage is lower than the threshold voltage, the output of the circuit is at a high level; only when the input signal voltage is higher than the threshold voltage, the output of the circuit is at a low level. The regulated voltage V1 of the zener diode string, the conduction voltage drop and the minimum drive current of the optocoupler module D1, and the resistance value of the resistor R1 and other parameters in the present utility model are relatively stable. The present utility model forms an RC filter circuit through the resistor R1 and the capacitor C1 at the input end, which can filter out the input signal jitter and high-frequency interference. The simulation results show that the present utility model can set a relatively accurate threshold voltage for digital signal acquisition and has good practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a circuit diagram of an acquisition circuit with voltage threshold control for aviation detection of digital signals in Example 1;

[0017] Figure 2 This is a circuit diagram of an acquisition circuit with voltage threshold control for aviation detection of digital signals in Example 2;

[0018] Figure 3 This is a simulation circuit diagram of an acquisition circuit with voltage threshold control for aviation detection of digital signals in Example 1;

[0019] Figure 4 Schematic diagram of a display page for an output signal OUT1 processed based on an input signal IN1 in Example 1;

[0020] Figure 5 Schematic diagram of a display page of an output signal OUT2 processed based on an input signal IN2 in Example 1. DETAILED DESCRIPTION

[0021] Example 1:

[0022] An acquisition circuit with voltage threshold control for aviation detection of digital signals, such as Figure 1 As shown, the circuit includes a Zener diode V1, a resistor R1, and an optocoupler module D1, which is an optocoupler or optocoupler relay. A capacitor C1 is connected in parallel between resistor R1 and optocoupler module D1. Resistor R1 and capacitor C1 form an RC filter circuit that can filter out input signal jitter and high-frequency interference.

[0023] like Figure 3 As shown, the voltage stabilizing diode V1 is of model IN4747, and the voltage stabilizing voltage V1=20V.

[0024] The resistor R1 is a 1% precision metal film resistor, R1=2.7KΩ.

[0025] The resistor R2 is a metal film resistor with a precision of 1%, R2=10KΩ.

[0026] The optocoupler module is an optocoupler, and the optocoupler D1 model is EL357N, the conduction voltage drop V2=1.2V, and the minimum driving current is I1=1mA.

[0027] The capacitor C1 is an electrolytic capacitor, C1=1uF.

[0028] The power supply voltage VCC is DC 5V.

[0029] The threshold voltage value of the acquisition circuit is V1 + V2 + I1 * R1 = 20 + 1.2 + 0.001 * 2700 = 23.9V. Therefore, the threshold voltage control of DC 23.9V can be achieved by using the above circuit parameters: when the input signal is less than 23.9V, the circuit outputs a high level of 5V; when the input signal is greater than 23.9V, the circuit outputs a low level. The circuit can be used for the acquisition of digital quantity signals of DC 28V / on in aviation products.

[0030] The cut-off frequency f0 = 1 / (2πRC) = 58.9Hz.

[0031] As Figure 3-Figure 5 shown, circuit simulation is carried out, and simulation signals IN1 and IN2 are respectively input, and circuit outputs OUT1 and OUT2 are measured. Among them, IN1 is a square wave signal with an amplitude of DC 20V and a frequency of 1Hz; IN2 is a square wave signal with an amplitude of DC 25V and a frequency of 1Hz.

[0032] As Figure 4 shown, when the input signal is IN1, the output signal OUT1 is always a high level of 5V; as Figure 5 shown, when the input signal is IN2, the output signal OUT2 is a square wave with an amplitude of 5V and a frequency of 1Hz. The simulation results are consistent with the design, and the utility model can set a relatively accurate threshold voltage for digital quantity acquisition.

[0033] Embodiment 2:

[0034] An acquisition circuit with voltage threshold control for digital quantity signals in aviation detection, as Figure 2 shown, includes a string of zener diodes, resistor R1, capacitor C1, optocoupler module D1 and resistor R2. The string of zener diodes includes zener diodes V1, V2, and V3 connected in series in sequence. The regulated voltage of the string of zener diodes is V1, the conduction voltage drop of the optocoupler module D1 is V2, the minimum drive current of D1 is I1, and the voltage of the input signal is V in .

[0035] When the input signal voltage V in < V1, the reverse voltage of the string of zener diodes does not reach its working voltage, the string of zener diodes does not conduct, D1 does not conduct, and the circuit output is a high level.

[0036] When the input signal voltage V1 < V in < V1 + V2, the reverse voltage of the string of zener diodes reaches its working voltage, the zener diodes conduct, the voltage drop of the string of zener diodes is equal to V1, but the voltage across D1 cannot reach its conduction voltage drop V2, D1 does not conduct, and the circuit output is a high level.

[0037] When the input signal voltage V1 + V2 < V inWhen V < V1 + V2 + I1 * R1, the reverse voltage of the voltage stabilizing diode string reaches its working voltage, the voltage stabilizing diode conducts, but the current passing through D1 does not reach its minimum drive current, D1 still does not conduct, and the circuit output is at a high level.

[0038] When V in >= V1 + V2 + I1 * R1, the reverse voltage of the voltage stabilizing diode string reaches its working voltage, the voltage stabilizing diode conducts, the current passing through D1 reaches its minimum drive current, D1 conducts, and the circuit output is at a low level.

[0039] V1 + V2 + I1 * R1 is the threshold voltage value of the circuit of the present invention. By reasonably selecting the parameters of the voltage stabilizing diode string, resistor R1 and optocoupler module D1, the threshold voltage value can be more accurately controlled.

[0040] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An acquisition circuit with voltage threshold control for detecting digital signals in aviation, characterized in that: It includes several voltage-stabilizing diodes, resistors R1, R2, capacitors C1 and optocoupler module D1 connected in series. The voltage-stabilizing diode at the output end is connected to the optocoupler module D1 through the resistor R1. A capacitor C1 is provided in parallel between the resistor R1 and the optocoupler module D1. The resistor R1 and the capacitor C1 form an RC filter circuit for filtering out input signal jitter and high-frequency interference. The first output end of the optocoupler module D1 is connected to the power supply voltage VCC through the resistor R2, and the second output end of the optocoupler module D1 is connected to the digital ground DGND. The voltage of the input digital signal is V in ; The regulated voltage of several zener diodes connected in series is V1; the on-state voltage drop of the optocoupler module D1 is V2, and the minimum driving current is I1; the threshold voltage value of the acquisition circuit is V1+V2+I1*R1; the model of the zener diode is IN4747, the resistor R1 and the resistor R2 are metal film resistors respectively, and the model of the optocoupler module D1 is EL357N.

2. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: The voltage-stabilizing diode at the output end is connected to one end of the light-emitting diode of the optical coupling module D1 through the resistor R1 , and the other ends of the capacitor C1 and the light-emitting diode of the optical coupling module D1 are both grounded.

3. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: The regulated voltage V1 of several zener diodes connected in series is 20V, the conduction voltage drop V2 of the optocoupler module D1 is 1.2V, and the minimum driving current is I1=1mA; the resistance value of the resistor R1 is 2.7KΩ, and the capacitance value of the capacitor C1 is 1uF; the threshold voltage value of the acquisition circuit is 23.9V.

4. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 3, characterized in that: The resistance of the resistor R2 is 10KΩ, and the power supply voltage VCC is DC 5V.

5. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: When V in <When V is less than V1, the zener diode is not turned on, the opto-coupler module D1 is not turned on, and the output of the acquisition circuit is at a high level.

6. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: When V1 < V in <When V1 + V2, the zener diode conducts, the voltage drop of the zener diode is equal to V1, the optocoupler module D1 does not conduct, and the output of the acquisition circuit is high level.

7. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: When V1 + V2 < V in When < V1 + V2 + I1 * R1, the zener diode conducts and the opto - coupler module D1 does not conduct, and the output of the acquisition circuit is high level.

8. The acquisition circuit with voltage threshold control for detecting digital signals in aviation according to claim 1, characterized in that: When V in When ≥V1+V2+I1*R1, the voltage regulator diode is turned on, the optocoupler module D1 is turned on, and the output of the acquisition circuit is low level.

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