A kind of amplifier circuit of compatibility electric current and temperature detection
Technical field
A kind of detection device applied to automatic fire alarm is the utility model is related to, especially a kind of compatible electric current and temperature
Spend the amplifier circuit of detection.
Background technology
Need to be detected leakage current when electrical fire monitoring detects and be also required to be detected distribution wire temperature.
Leakage current is detected generally using residual current transformer as sensor, the output of the sensor is electric current, detects distribution wire temperature
Degree is general to use temperature sensor, and sensor output is resistance.Therefore, complex circuit, cost is higher, and antijamming capability is not
By force, detection is inaccurate.
Utility model content
The utility model aim is to provide a kind of compatible electric current and the amplifier circuit of temperature detection, can detect electric leakage
Stream, can also detect circuit temperature value, and simple with circuit, cost is low, and strong antijamming capability, detects the advantages of accurate.
To achieve the above object, the utility model provides following technical solution:
A kind of compatible electric current of the utility model and the amplifier circuit of temperature detection, including residual current transformer,
Temperature sensor, the amplifier circuit include signaling conversion circuit, signal amplification circuit, signaling conversion circuit input terminal point
It is not connected with residual current transformer, temperature sensor, signaling conversion circuit output terminal is connected with signal amplification circuit, works as progress
During leakage current test, the current signal of residual current transformer is converted to voltage signal by the resistance of signaling conversion circuit, into
Row amplifier, obtains detected value;When carrying out temperature detection, dut temperature is converted to resistance value by temperature sensor, with letter
The more smooth resistance of resistance v. temperature correspondence is formed after the resistor coupled in parallel of number conversion circuit, is converted to voltage signal;Conversion
Voltage signal afterwards amplifies through signal amplification circuit, and signal is amplified to the voltage signal output of suitable A/D conversion circuits.
Wherein, the signaling conversion circuit includes metal-oxide-semiconductor Q1, one R1 of resistance, two R2 of resistance, one C1 of capacitance, the metal-oxide-semiconductor
Q1 is connected with two R2 of resistance, power supply, controlling switch respectively, two R2 of resistance respectively with signaling conversion circuit input terminal, resistance
One R1, one C1 of capacitance, the connection of signaling conversion circuit output terminal;Controlling switch is opened for the conversion of detection leakage current and temperature detection
Close.
Wherein, the signal amplification circuit includes three R3 of resistance, four R4 of resistance, five R5 of resistance, six R6 of resistance, operation amplifier
Device D1A, capacitance four C4, the operational amplifier D1A respectively with three R3 of resistance, four R4 of resistance, five R5 of resistance, six R6 of resistance, electricity
Source connects, and resistance three is connected with signaling conversion circuit output terminal, and six R6 of resistance is connected with four C4, A/D conversion circuit of capacitance respectively.
Compared with prior art, the beneficial effects of the utility model are:
Leakage current can be detected, can also detect circuit temperature value, simple with circuit, cost is low, strong antijamming capability, inspection
Survey the advantages of accurate.
Brief description of the drawings
Fig. 1 is the structure diagram of the utility model.
In figure, Q1, metal-oxide-semiconductor;C1, capacitance one;C4, capacitance four;R1, resistance one;R2, resistance two;R3, resistance three;R4, electricity
Resistance four;R5, resistance five;R6, resistance six;D1A, operational amplifier;VCC, power supply;A/D, A/D conversion circuit;I1、I 2:Signal
Conversion circuit input terminal.
Embodiment
The following is a combination of the drawings in the embodiments of the present utility model, and the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are without making creative work
All other embodiments obtained, shall fall within the protection scope of the present invention.
Please refer to Fig.1:
In the utility model embodiment, a kind of compatible electric current of the utility model and the amplifier circuit of temperature detection,
Including residual current transformer, temperature sensor, the amplifier circuit includes signaling conversion circuit, signal amplification circuit,
Signaling conversion circuit input terminal is connected with residual current transformer, temperature sensor respectively, signaling conversion circuit output terminal and letter
The connection of number amplifying circuit, when carrying out leakage current test, the current signal of residual current transformer passes through signaling conversion circuit
Resistance is converted to voltage signal, carries out amplifier, obtains detected value;When carrying out temperature detection, dut temperature is passed by temperature
Sensor is converted to resistance value, with forming the more smooth electricity of resistance v. temperature correspondence after the resistor coupled in parallel of signaling conversion circuit
Resistance, is converted to voltage signal;Transformed voltage signal amplifies through signal amplification circuit, and signal is amplified to suitable A/D conversions electricity
The voltage signal output on road.
The signaling conversion circuit includes metal-oxide-semiconductor Q1, one R1 of resistance, two R2 of resistance, capacitance one C1, the metal-oxide-semiconductor Q1 point
Be not connected with two R2 of resistance, power supply, controlling switch, two R2 of resistance respectively with signaling conversion circuit input terminal, one R1 of resistance,
One C1 of capacitance, the connection of signaling conversion circuit output terminal.
The signal amplification circuit includes three R3 of resistance, four R4 of resistance, five R5 of resistance, six R6 of resistance, operational amplifier
D1A, capacitance four C4, the operational amplifier D1A respectively with three R3 of resistance, four R4 of resistance, five R5 of resistance, six R6 of resistance, power supply
Connection, resistance three are connected with signaling conversion circuit output terminal, and six R6 of resistance is connected with four C4, A/D conversion circuit of capacitance respectively.
The utility model further illustrates:When carrying out leakage current test, metal-oxide-semiconductor Q1 cut-offs, current signal passes through electricity
Hinder a R1 and be converted to voltage signal;When carrying out temperature detection, metal-oxide-semiconductor Q1 conductings, dut temperature is converted to by temperature sensor
Resistance value, the more smooth resistance of resistance v. temperature correspondence is formed after in parallel with one R1 of resistance, by with two R2 of resistance to electricity
The partial pressure of source VCC, is converted to voltage signal;Transformed voltage signal is coupled to opamp input terminal through three R3 of resistance,
Operational amplifier amplification factor is determined that signal is amplified to the voltage letter of suitable A/D conversion circuits by four R4 of resistance, five R5 of resistance
Number, exported after six R6 of resistance, four C4 low-pass filtering of capacitance.The controlling switch is progress leakage current test with being examined into trip temperature
The change-over switch of survey.
It is obvious to a person skilled in the art that the utility model is not limited to the details of above-mentioned one exemplary embodiment, and
And in the case of the spirit or essential attributes without departing substantially from the utility model, it can realize that this practicality is new in other specific forms
Type.Therefore, in all respects, the present embodiments are to be considered as illustrative and not restrictive, this practicality is new
The scope of type is indicated by the appended claims rather than the foregoing description, it is intended that the equivalency fallen in claim is contained
All changes in justice and scope are embraced therein.Any reference numeral in claim should not be considered as limitation
Involved claim.
Moreover, it will be appreciated that although the present specification is described in terms of embodiments, not each embodiment is only wrapped
Containing an independent technical solution, this narrating mode of specification is only that those skilled in the art should for clarity
Using specification as an entirety, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art
It is appreciated that other embodiment.