CN203037713U - Multiple-signal collection device used for fire hazard detector - Google Patents

Abstract

The utility model relates to a multi-signal acquisition device for a fire monitoring detector, which comprises sequentially connected sensors, a sampling resistance circuit, a voltage clamp protection circuit, a filter circuit and a main chip. Compared with the prior art, the utility model has the advantages of flexible function transformation, low realization cost, convenient layout and optimized wiring.

Description

A multi-signal acquisition device for fire detectors

technical field

The utility model relates to a signal acquisition device, in particular to a variety of signal acquisition devices used for fire monitoring detectors.

Background technique

At present, most of the fire monitoring detectors on the market have relatively simple functions, such as special measurement of residual current, special measurement of temperature or special monitoring of power distribution. In today's increasingly tense energy environment, electricity consumption must be carefully calculated, so it is necessary to accurately measure electric energy , Quantify the power consumption. In view of the above situation, there is already a comprehensive detector in the market that combines power distribution monitoring, fire monitoring, and electric energy measurement.

At the same time, in order to realize the detectors with the above functions, it is necessary to collect signals such as voltage, current, residual current, temperature, etc., which requires a variety of different collection circuits to be integrated into one circuit board. , resulting in the need to purchase more complex types of components, wiring layout on the circuit board is also more troublesome, and it also increases the cost for the enterprise. And because each acquisition circuit has its own purpose, the corresponding function of each acquisition circuit is fixed, and the function characteristic change is not flexible.

Utility model content

The purpose of this utility model is to provide a variety of signal acquisition devices for fire monitoring detectors with flexible function conversion, low implementation cost, convenient layout and optimized wiring in order to overcome the above-mentioned defects in the prior art.

The purpose of this utility model can be achieved through the following technical solutions:

A multi-signal acquisition device for fire monitoring detectors is characterized in that it includes sequentially connected sensors, a sampling resistance circuit, a voltage clamping protection circuit, a filter circuit and a main chip.

The sensors include voltage transformers, current transformers, residual current transformers and temperature sensors.

The sampling resistor circuit includes a sampling resistor R1, a capacitor C1, a capacitor C2 and a reference voltage VREF. The sampling resistor R1 is connected in parallel at both ends of the sensor. The input end of the circuit is connected, the other end of the sampling resistor R1 is respectively connected with one end of the capacitor C2 and the reference voltage VREF, and the other end of the capacitor C1 and the other end of the capacitor C2 are grounded.

If the temperature sensor is a heat-sensitive temperature sensor, the sampling resistance circuit includes a sampling resistance R and a reference voltage VREF, one end of the heat-sensitive temperature sensor is grounded through the sampling resistance R, and the other end is connected to the reference voltage VREF.

The voltage clamp protection circuit is a dual diode device Q1 composed of a first diode and a second diode connected in reverse parallel, wherein the cathode of the first diode and the anode of the second diode are both connected to Between the output end of the sampling resistance circuit and the input end of the filter circuit, the anode of the first diode is grounded, and the cathode of the second diode is connected to the reference power supply 3.3V.

The filter circuit includes a resistor R2 and a capacitor C3. One end of the resistor R2 is connected to the output end of the voltage clamping protection circuit, and the other end is connected to one end of the capacitor C3 and the main chip, and the other end of the capacitor C3 is grounded.

Compared with the prior art, the utility model has the following advantages:

1. This device is used on the circuit board inside the detector, which can realize the signal acquisition of three-phase voltage, three-phase current, residual current and temperature; it can also convert the signal acquisition circuit of three-phase voltage or three-phase current into residual The current or temperature signal acquisition circuit realizes multi-circuit fire monitoring, and the function transformation is flexible;

2. The components of this device are resistors, capacitors and diodes, all of which can be packaged by SMD. These devices are cheap and convenient to purchase in the market. At the same time, since multiple acquisition circuits are the same, it is more convenient to have a layout on the circuit board. Optimized Advantages of routing.

Description of drawings

Fig. 1 is the general circuit diagram of the present utility model;

Fig. 2 is a circuit diagram of the sensor of the present invention being a heat-sensitive temperature sensor.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

The utility model is suitable for the acquisition of three-phase voltage, three-phase current, residual current and temperature signals. Since these signals can use the same acquisition circuit, the main difference is that the voltage acquisition relies on the voltage transformer, and the current acquisition relies on the current mutual inductance. The residual current acquisition relies on the residual current transformer, and the temperature signal acquisition relies on the temperature sensor.

As shown in FIG. 1 , the utility model includes a sensor, a sampling resistor circuit 10 , a voltage clamping protection circuit 20 , a filter circuit 30 and a main chip connected in sequence. The sensors include voltage transformers, current transformers, residual current transformers and temperature sensors.

The sampling resistor circuit includes a sampling resistor R1, a capacitor C1, a capacitor C2 and a reference voltage VREF. The sampling resistor R1 is connected in parallel at both ends of the sensor. The input end of the circuit is connected, the other end of the sampling resistor R1 is respectively connected with one end of the capacitor C2 and the reference voltage VREF, and the other end of the capacitor C1 and the other end of the capacitor C1 are both grounded.

As shown in Figure 2, if the temperature sensor is a heat-sensitive temperature sensor, the sampling resistor circuit includes a sampling resistor R and a reference voltage VREF, one end of the thermal-sensitive temperature sensor is grounded through the sampling resistor R, and the other end is connected to the reference voltage VREF. voltage VREF connection.

The voltage clamp protection circuit is a dual diode device Q1 composed of a first diode and a second diode connected in reverse parallel, wherein the cathode of the first diode and the anode of the second diode are both connected to Between the output end of the sampling resistance circuit and the input end of the filter circuit, the anode of the first diode is grounded, and the cathode of the second diode is connected to the reference power supply 3.3V.

The filter circuit includes a resistor R2 and a capacitor C3. One end of the resistor R2 is connected to the output end of the voltage clamping protection circuit, and the other end is connected to one end of the capacitor C3 and the main chip, and the other end of the capacitor C3 is grounded.

The working principle of the utility model is as follows:

The analog current signal collected by the transformer is used to obtain the potential voltage at A through the sampling resistor R1, and the capacitors C1 and C2 play the role of filtering.

The interior of the electronic component Q1 is composed of 2 diodes, and the diode has the characteristic of unidirectional conduction. When the voltage obtained in the sampling circuit 10 exceeds 3.3V, the pin 3 and pin 2 of Q1 are turned on. At this time, the 3 pin of the component Q1 The pin voltage is 3.3V. When the voltage obtained in the sampling circuit 10 is lower than 0V, pin 3 and pin 1 of Q1 are turned on, and the voltage of pin 3 of component Q1 is 0V.

Resistor R2 and capacitor C3 form an RC filter circuit, which mainly filters high-frequency harmonics and clutter in the circuit, and transmits pure analog voltage small signals to the main chip for processing and calculation.

The principle of the voltage and current acquisition circuit is the same as that of the residual current acquisition circuit. An analog current is collected through the mutual inductance transformer. For the thermistor temperature sensor, since the collected is not an electrical parameter, but a resistance value, in this case As long as the resistor R1 and capacitor C2 are not installed, the capacitor at C1 can be replaced with a resistor, so that the voltage at A can also be obtained (as shown in Figure 2).

Claims (6)

1. a kind of multiple signal acquisition device for fire detector, is characterized in that, comprises the sensor that connects successively, sampling resistance circuit, voltage clamp protection circuit, filtering circuit and main chip. the 2. A multiple signal acquisition device for fire monitoring detectors according to claim 1, wherein said sensors include voltage transformers, current transformers, residual current transformers and temperature sensors. the 3. A variety of signal acquisition devices for fire detectors according to claim 1, wherein said sampling resistor circuit includes sampling resistor R1, capacitor C1, capacitor C2 and reference voltage VREF, said The sampling resistor R1 is connected in parallel to both ends of the sensor, one end of the capacitor C1 is respectively connected to one end of the sampling resistor R1 and the input end of the voltage clamping protection circuit, and the other end of the sampling resistor R1 is respectively connected to one end of the capacitor C2 and the reference voltage VREF connected, the other end of the capacitor C1 and the other end of the capacitor C2 are grounded. the 4. A variety of signal acquisition devices for fire detectors according to claim 2, wherein if the temperature sensor is a heat-sensitive temperature sensor, the sampling resistor circuit includes a sampling resistor R and a reference voltage VREF, one end of the thermistor temperature sensor is grounded through the sampling resistor R, and the other end is connected to the reference voltage VREF. the 5. A variety of signal acquisition devices for fire detectors according to claim 1, wherein the voltage clamping protection circuit is composed of a first diode and a second two diodes connected in reverse parallel A dual diode device Q1 composed of pole tubes, wherein the cathode of the first diode and the anode of the second diode are connected between the output terminal of the sampling resistor circuit and the input terminal of the filter circuit, and the first diode The anode of the tube is grounded, and the cathode of the second diode is connected to the reference power supply 3.3V. the 6. A variety of signal acquisition devices for fire detectors according to claim 1, wherein the filter circuit includes a resistor R2 and a capacitor C3, and one end of the resistor R2 is connected to a voltage clamp protection The output end of the circuit is connected, and the other end is respectively connected with one end of the capacitor C3 and the main chip, and the other end of the capacitor C3 is grounded. the

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