CN1655204A - Signal output unit - Google Patents
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- CN1655204A CN1655204A CN 200510053550 CN200510053550A CN1655204A CN 1655204 A CN1655204 A CN 1655204A CN 200510053550 CN200510053550 CN 200510053550 CN 200510053550 A CN200510053550 A CN 200510053550A CN 1655204 A CN1655204 A CN 1655204A
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Abstract
This invention discloses a signal output device including: a signal generation unit, a first amplifier, a first switch, a second switch, a MOS, a current sampling resistor, output terminals A, B, C, and D, among which, the signal generation unit can be a signal output circuit composed of D/M converter and a second amplifier for generating voltage and frequency signals provided to the back to be output. When the back operates a current feedback way, MOS, the current sampling resistor and a first amplifier make up of a current feedback circuit to form a constant current load analog circuit used in current output, when the back works in a voltage feedback way, the first amplifier makes up of frequency and voltage output. The signal output device can output various kinds of standard signals.
Description
Technical field
The present invention relates to automation field, relate in particular to a kind of signal output apparatus.
Background technology
At present, at a lot of industrial circles, adopt various instrument to obtain various indexs usually, so that carry out the Industry Control in this field in view of the above.Instrument is divided into field measuring instrument and pulpit instrument according to the difference of infield.Field measuring instrument comprises temperature transmitter, pressure unit, flowmeter etc., they generally are installed near the measurement point, in order to the industry spot information translation is become quantification signals such as voltage, electric current, frequency transfer to the pulpit, so that the pulpit instrument shows or other works of treatment.
No matter be that field measuring instrument or pulpit instrument all need regularly to carry out the instrument maintenance, guarantee the accuracy and the stability of instrument.The importance that instrument is safeguarded is to carry out the verification of instrument by various calibration equipments.And various calibration equipments provide by signal output apparatus and meet national instrument of measuring the standard signal of relevant regulations to the needs verification, to carry out the verification of those instrument.At the type difference that standard signal is provided, need different signal output apparatus, produce multiple calibration equipment thus.
Such as: flowmeter is the field measuring instrument that is used for measuring the object flow velocity, and it converts the flow velocity signal of object to frequency signal, reflects the speed of present object flow velocity by the height of frequency.Because the different types of traffic meter is exported the signal of different amplitude ranges, so the calibration equipment of checking flow meter need adopt the signal output apparatus that output frequency is adjustable, amplitude is adjustable.
For another example: industrial application is field measuring instrument such as pressure unit very widely, and those instrument are to adopt industrial standard 4～20mA current delivery pattern.The characteristics of this current delivery pattern are that signal can adopt two-wire system or adopt three-wire system.Generally, two-wire system is meant that signal and power supply transmit on same cable.When applying certain supply voltage on the signal wire, the electric current that flows through signal wire has been represented signal magnitude, and can not change with voltage, has constant-current characteristics.What the employing three-wire system was meant wherein a pair of line transmission is the current signal of 4～20mA.For the instrument of two-wire system pattern, the signal output apparatus of the calibration equipment of this kind of verification instrument need provide steady current, and this steady current can be set.For the instrument of three-wire system pattern, the signal output apparatus of the calibration equipment of this kind of verification instrument need provide the current signal of variable-magnitude.
At present and since industrial instrument when moving at the scene dismounting all very inconvenient, so verification work is preferably in the scene and carries out.And each automatic control system all comprises a lot of instrument, if need those dissimilar instrument of verification, then the verification personnel will carry a lot of calibration equipments, yet calibration equipment is relatively heavier again, cause carrying inconvenience thus, and the use of dissimilar calibration equipments is not quite similar, such as: the amplitude of the artificial signalization of needs, frequency etc. cause the complicacy of using thus.That is, there is the single defective of output signal type in signal output apparatus in the prior art, and it is wide and be applicable to the calibration equipment of field-checking to lack the verification scope thus, and then brings instrument check complexity, inconvenient trouble for the verification personnel.
Summary of the invention
The object of the present invention is to provide a kind of signal output apparatus, to solve the single technological deficiency of output signal in the prior art.
For addressing the above problem, the invention discloses a kind of signal output apparatus, comprise: signal generation unit, first amplifier, first change-over switch, second change-over switch, MOS, current sampling resistor, lead-out terminal A, lead-out terminal B, lead-out terminal C and lead-out terminal D, wherein: the signal generation unit, in order to produce voltage signal; First amplifier, its in-phase input end connect described signal generation unit, and inverting input connects second change-over switch, and output terminal connects first change-over switch; First change-over switch comprises first switching point and second switching point, and wherein, the output terminal of first switching point connects the grid of MOS, and the output terminal of second switching point connects lead-out terminal A; Second change-over switch comprises the 3rd switching point and the 4th switching point, and wherein, the output terminal of the 3rd switching point connects the drain electrode of MOS, and the output terminal of the 4th switching point connects lead-out terminal A; MOS, its source electrode connects lead-out terminal D, its drain electrode by current sampling resistor be connected to lead-out terminal B; Lead-out terminal C is connected to a power supply.
First change-over switch and second change-over switch are programmed switch.
Wherein, also comprise first controller, described first controller connects the program control input end of first change-over switch and the program control input end of second change-over switch respectively, is used to control first change-over switch in the switching between first switching point and second switching point, the switching of second change-over switch between the 3rd switching point and the 4th switching point.
Described signal generation unit comprises reference voltage source, D/A and second controller, wherein:
The input end of D/A connects reference voltage source, and its output terminal connects the in-phase input end of described first amplifier;
Second controller connects the program control input end of D/A, is used to control the magnitude of voltage of the output terminal of D/A.
Described signal generation unit also comprises second amplifier, connects the D/A and first amplifier respectively, and an one input end connects D/A, and another input end connects ground, and its output terminal connects the in-phase input end of first amplifier.
Described signal generation unit also comprises the 3rd change-over switch that is arranged between the D/A and second amplifier, described the 3rd change-over switch comprises the 5th switching point and the 6th switching point, the input end of the 5th switching point connects the output terminal of D/A, the input end of the 6th switching point connects ground, and the output terminal of described the 3rd change-over switch connects the in-phase input end of second amplifier.
Described the 3rd change-over switch is a programmed switch, and the program control input end of described the 3rd change-over switch connects second controller, is used to control the output voltage values of the 3rd change-over switch.
Described second amplifier is a programmable amplifier, and described second controller connects the program control input end of second amplifier, is used to control the output valve of second amplifier.
Described first controller and second controller can be integrated into a controller.
Described controller is the parts with FPGA (Field Programmable Gate Array) fan-out capability.Compared with prior art, the present invention has the following advantages:
First: the present invention adopts two change-over switches, and two kinds of mode of operations of output voltage signal and current signal make that voltage signal and current signal can the shared signal generating unit and first amplifiers, have reduced device thus.And signal output apparatus of the present invention not only can output voltage signal, also can obtain current signal, has overcome the single defective of signal output apparatus output signal.
Second: the lead-out terminal of Constant Current Load signal of the present invention is shared with a lead-out terminal of voltage, current signal respectively, thereby reduces the use of terminal, has simplified the device in the device thus, and has reduced production cost;
The 3rd: the present invention produces the frequency output signal of controllable amplitude and frequency by changing the logic output state of controller, makes the shared output of frequency signal and voltage signal, has simplified the circuit in the device thus, and then has reduced production cost.
Description of drawings
Fig. 1 is the structural representation of a kind of signal generation device of the present invention;
Fig. 2 is the structural representation of another signal output apparatus of the present invention;
Fig. 3 is first kind of structural representation of signal generation unit of the present invention;
Fig. 4 is disclosed second kind of signal generation unit structural representation on Fig. 3 basis;
Fig. 5 is disclosed the third signal generation unit structural representation on Fig. 3 basis
Fig. 6 is the program control synoptic diagram of second amplifier among Fig. 5;
Fig. 7 is the structural representation of a kind of embodiment of signal output apparatus of the present invention.
Fig. 8 is a signal controller structure principle chart of the present invention;
Embodiment
Below in conjunction with accompanying drawing, specify the present invention.
See also Fig. 1, it is the structural representation of a kind of signal generation device of the present invention.It comprises: signal generation unit 11, first amplifier 12, first change-over switch 13, second change-over switch 14, MOS15, current sampling resistor 16, power supply VPP, lead-out terminal A, lead-out terminal B, lead-out terminal C and lead-out terminal D, wherein:
First change-over switch 13, comprise the first switching point S11 and the second switching point S12, wherein, the output terminal that links to each other with the first switching point S11 (being called for short the S11 output terminal down) is connected the grid G of MOS15, and the output terminal that links to each other with the second switching point S12 (being called for short the S12 output terminal down) is connected lead-out terminal A;
Second change-over switch 14, comprise the 3rd switching point S21 and the 4th switching point S22, wherein, the output terminal that links to each other with the 3rd switching point S21 (being called for short the S21 output terminal down) is connected the drain electrode G of MOS15, and the output terminal that links to each other with the 4th switching point S22 (being called for short the S22 output terminal down) is connected lead-out terminal A;
MOS15, its source S connects lead-out terminal D, and its drain D connects ground (zero level GND) and lead-out terminal B by current sampling resistor 16;
Lead-out terminal C is connected to a power supply Vpp.
First change-over switch 13 and second change-over switch 14 can adopt Manual Transfer Switch, also can adopt program control change-over switch.For the ease of control, the present invention adopts program control change-over switch.See also Fig. 2, it is for the structural representation of another signal output apparatus of the present invention.Signal output apparatus of the present invention also comprises first controller 17, the program control input end of first change-over switch 13 and second change-over switch 14 is connected first controller 17, by first controller 17 control, first change-over switch 13 in the switching between the first switching point S11 and the second switching point S12 and control the switching of second change-over switch 14 between the 3rd switching point S21 and the 4th switching point S22.
The change-over switch control sub unit is used to control first change-over switch 13 in the switching between the first switching point S11 and the second switching point S12 and control the switching of second change-over switch 14 between the 3rd switching point S21 and the 4th switching point S22.
The principle of work of above-mentioned disclosed signal output apparatus is simply introduced by following elder generation.
When first change-over switch 13 place the S12 switching point, when second change-over switch 14 places the S22 switching point, first amplifier 12 constitutes signal follower.If first amplifier 12 is an operational amplifier, then the output voltage V u of lead-out terminal A is identical with input voltage Vp, i.e. Vu=Vp.
When first change-over switch 13 place the S11 switching point, when second change-over switch 14 places the S21 switching point, first amplifier 12, MOS15, current sampling resistor R16, power supply VPP and zero level GND constitute converter.When applying a load between lead-out terminal C and the lead-out terminal D, because the signal feedback of current sampling resistor 16 is to first amplifier 12, the grid G of the output voltage control MOS15 of first amplifier 12, make the electric current in the load identical with the electric current maintenance on the current sampling resistor 16, be I=Vp/R, wherein R is the resistance of current sampling resistor 16.
Equally, when adding a power supply between lead-out terminal D and the lead-out terminal B, the output current of power supply also is I=Vp/R, has so just formed Constant Current Load, in certain supply voltage and internal resistance of source scope, and this electric current and supply independent.
MOS15 can adopt the N slot field-effect transistor, and when adding certain voltage between grid G and the drain D, the maximum current between its source S and the drain D is relevant with the voltage that applies, and the high more electric current that flows through of voltage is big more.Convert current signal to inverting input that voltage signal is input to first amplifier 12 by current sampling resistor 16, thereby form degeneration factor, make electric current keep constant.
Next introduce and how to use signal receiving device.
When signal output apparatus need be exported the voltage of a certain amplitude, then the input end with instrument to be verified was connected on lead-out terminal A and the lead-out terminal B, and placed S12 switching point, second change-over switch 14 to place the S22 switching point first change-over switch 13.If first changes switch 13 and second change-over switch 14 is program control change-over switches, then control the switching of first change-over switch 13 and second change-over switch 14 by first controller 17, such as: when the program control input end of first change-over switch 13 and second change-over switch 14 input logic " 1 " all, then first change-over switch 13 switches to the S11 switching point, second change-over switch 14 switches to the S21 switching point; When the program control input end of first change-over switch 13 and second change-over switch 14 input logic " 0 " all, then first change-over switch 13 switches to the S12 switching point, and second change-over switch 14 switches to the S22 switching point.The input logic of importing the program control input end of first change-over switch 13 and second change-over switch 14 by first controller is " 0 ", and then the voltage between lead-out terminal A and the lead-out terminal B is the output voltage of first amplifier.If first amplifier 12 is an operational amplifier, then the voltage between lead-out terminal A and the lead-out terminal B is the input voltage of first amplifier 12, can obtain desired magnitude of voltage by the voltage that changes 11 outputs of signal generation unit.
When signal output apparatus need be exported the electric current of a certain amplitude, then need the input end of instrument to be verified is connected between lead-out terminal C and the lead-out terminal D.First change-over switch 13 places S11 switching point, second change-over switch 14 to place the S21 switching point.Lead-out terminal C meets voltage source V PP, and its voltage amplitude should be enough to overcome the voltage that current sampling resistor 16 and extension instrument caused to be reduced.Electric current is flowed out by lead-out terminal C, is flowed into by lead-out terminal D.Its current value is I=Vp/R, thereby by changing the current amplitude that Vp changes output.
When signal output apparatus, then needs the input end of instrument to be verified is connected between lead-out terminal D and the lead-out terminal B during Constant Current Load as simulation.First change-over switch 13 places S11 switching point, second change-over switch 14 to place the S21 switching point.Electric current is flowed into by lead-out terminal D, is flowed out by lead-out terminal B.Its current value is I=Vp/R, thereby by changing the current amplitude that Vp changes Constant Current Load.
The signal generation unit can directly adopt signal generators such as direct voltage source.The invention also discloses other several signal generation units.Those signal generation units can make output voltage V p that the variation of different amplitudes and frequency takes place under the control of controller.
See also Fig. 3, it is for first kind of structural representation of signal generation unit of the present invention.It comprises reference voltage source 21, D/A 22 and second controller 23, wherein:
The input end of D/A 22 connects reference voltage source 21, and its output terminal connects the in-phase input end of described first amplifier 12;
D/A 22 is the devices that digital signal converted to simulating signal, and Vref wherein comes from the reference source 21 of outputting standard voltage, its output be constant voltage signal.The output end signal level Vout of D/A 22 changes with the variation of the numerical value of program control input end input, and satisfies Vout=K1*Vref, and wherein K1 is the numerical value of program control input end input.Because Vref is constant level,, just can obtain the Vout level that needs as long as program control input end provides different K1 values.According to the principle of general D/A 22, the value of K1 can only be between-1 and 1, and like this, the level range of Vout is [Vref, Vref], and the level range that promptly exports the Vp of first amplifier to is [Vref, Vref].
In order further to expand the output area of level, can also adopt second kind of signal generation unit.See also Fig. 4, it is for disclosing second kind of signal generation unit structural representation on Fig. 3 basis.Described signal generation unit comprises reference voltage source 21, D/A 22, second controller 23 and second amplifier 25, wherein:
The input end of D/A 22 connects reference voltage source 21;
The enlargement factor of second amplifier 25 is program-controlled, and its output Vp is the multiple of input voltage Vf, i.e. Vp=K2*Vf.Multiple K2 is by the program control input end control of this device.When K2 presses a certain frequency change, just produced frequency signal.In order to obtain the voltage of different amplitudes, multiple K2 can also can also can be negative less than 1 greater than 1, with the limited problem of compensation K1 multiple.
The parts of above-mentioned second controller 23 for having the FPGA (Field Programmable Gate Array) fan-out capability can be CPU, MPU, DSP, PLD, FPGA, ASIC, SOC and other logical devices etc., and the combination of these logical devices.Second controller 23 further is:
Converter control sub unit: the amplification coefficient K1 that is used to control D/A;
Amplification coefficient control sub unit: the amplification coefficient K2 that is used to control second amplifier.
Programmable amplifier can change the amplitude of signal, when enlargement factor is pressed certain frequency change, just can produce frequency signal.But the multiple of general programmable amplifier needs the combination of a plurality of logical signals to control, and when frequency is exported, has increased the operand of second controller 23.
Be the structure of further optimal controller, reduce operand, can also adopt the third signal generation unit.See also Fig. 5, it is for disclosing the third signal generation unit structural representation on Fig. 4 basis.Described signal generation unit comprises reference voltage source 21, D/A 22, second controller 23, the 3rd change-over switch 24 and second amplifier 25, wherein:
The input end of D/A 22 connects reference voltage source 21;
The 3rd change-over switch 24, comprise the 5th switching point S31 and the 6th switching point S32, the input end of the 5th switching point S31 connects the output terminal of D/A 22, and the input end of the 6th switching point S32 connects ground, and the output terminal of described the 3rd change-over switch 24 connects the in-phase input end of second amplifier 25;
When the 3rd change-over switch 24 placed S31, the output voltage V out of D/A 22 was input to the in-phase input end of second amplifier 25.When the 3rd change-over switch 24 was switched between S31 and S32, then the in-phase input end of second amplifier 25 was imported Vout level and zero level respectively.The 3rd change-over switch 24 can be program control, and when being input as certain frequency signal, the in-phase input end that then is input to second amplifier 25 also is the signal of same frequency when program control.As shown in Figure 6, when being input as logical one, the 3rd change-over switch 24 is positioned at S31, Vf=Vout when program control; When being input as logical zero, the 3rd change-over switch 24 is positioned at S32, Vf=0 when program control.
The enlargement factor of second amplifier 25 is program-controlled, and its output Vp is the multiple of input voltage Vf, i.e. Vp=K2*Vf.Multiple K2 is by the program control input end control of this device.In order to obtain the voltage of different amplitudes, multiple K2 can be greater than 1, also can be less than 1, with the limited problem of compensation K1 multiple.
The parts of above-mentioned second controller 23 for having the FPGA (Field Programmable Gate Array) fan-out capability can be CPU, MPU, DSP, PLD, FPGA, ASIC, SOC and other logical devices etc., and the combination of these logical devices.Second controller 23 further is:
Converter control sub unit: the amplification coefficient K1 that is used to control D/A;
Change-over switch control sub unit: be used for control its switch and between S31 and S32, switch;
Amplification coefficient control sub unit: the amplification coefficient K2 that is used to control second amplifier.
Below at above-mentioned disclosed signal generation unit, the present invention is an example with an embodiment, specifies the principle of work of signal output apparatus.
Embodiment
See also Fig. 7, it is the structural representation of a kind of embodiment of signal output apparatus of the present invention.It comprises signal generation unit, first amplifier 12, first change-over switch 13, second change-over switch 14, MOS15, current sampling resistor 16, controller 26, lead-out terminal A, lead-out terminal B, lead-out terminal C and lead-out terminal D.Wherein the signal generation unit comprises reference voltage source 21, D/A 22, the 3rd change-over switch 24 and second amplifier 25.The output terminal of second amplifier 25 of signal generation unit connects the in-phase input end of first amplifier 12.
The controller 26 of present embodiment is integrated by first controller and second controller.See also Fig. 8, it is the structure principle chart of the controller of present embodiment.Controller 26 comprises signal output control sub unit 261, the first change-over switch control sub unit 262, converter control sub unit 263, the second change-over switch control sub unit 264, amplification coefficient control sub unit 265.Wherein:
The first change-over switch control sub unit 262 is used to control first change-over switch 13 in the switching between the first switching point S11 and the second switching point S12 and control the switching of second change-over switch 14 between the 3rd switching point S21 and the 4th switching point S22;
Converter control sub unit 263: the amplification coefficient K1 that is used to control D/A;
The second change-over switch control sub unit 264: be used for control its switch and between S31 and S32, switch;
Amplification coefficient control sub unit 265: the amplification coefficient that is used to control second amplifier;
Signal output control sub unit 261: connect the first change-over switch control sub unit 262, converter control sub unit 263, the second change-over switch control sub unit 264, amplification coefficient control sub unit 265 respectively, be used for
(1) when receiving device when being operated in the voltage output state, sends instruction, make second change-over switch control sub unit 264 controls the 3rd change-over switch 24 place S31 to the second change-over switch control sub unit 264; Send instruction to the first change-over switch control sub unit 262, make the change-over switch 13 of winning place S12, second change-over switch 14 to place S22; Send the K1 value that this controller receives to converter control sub unit 263, so that the amplification coefficient of adjusting D/A 22 is to the K1 value that receives; Send the K2 value that this controller receives to amplification coefficient control sub unit 265, so that the amplification system of regulating second amplifier 25 is to the K2 value, described K1 and K2 value can be that the user inputs to controller 26 by peripheral hardware, also can be to obtain according to calculating with input value;
(2) when device is operated in the frequency output state, send instruction to the second change-over switch control sub unit 264, make second change-over switch control sub unit 264 controls the 3rd change-over switch 24 between S31 and S32, switch; Send instruction to the first change-over switch control sub unit 262, make the change-over switch 13 of winning place S12, second change-over switch 14 to place S22; Send the K1 value that this controller receives to converter control sub unit 263, so that the amplification coefficient of adjusting D/A 22 is to the K1 value that receives; Send the K2 value that these controllers receive to amplification coefficient control sub unit 265, so that the amplification system of regulating second amplifier 25 is to the K2 value;
(3) circuit working sends instruction to the second change-over switch control sub unit 264 when the electric current output state, makes second change-over switch control sub unit 264 controls the 3rd change-over switch 24 place S31; Send instruction to the first change-over switch control sub unit 262, make the change-over switch 13 of winning place S11, second change-over switch 14 to place S21; Send the K1 value that this controller receives to converter control sub unit 263, so that the amplification coefficient of adjusting D/A 22 is to the K1 value that receives; Send the K2 value that these controllers receive to amplification coefficient control sub unit 265, so that the amplification system of regulating second amplifier 25 is to the K2 value.
Based on said structure, the principle of work of the signal output apparatus of present embodiment is described below.
When device is operated in the voltage output state, program-controlled the 3rd change-over switch 24 places S31, first change-over switch 13 places S12, second change-over switch 14 to place S22, the output level Vout of D/A 22 is input to the in-phase input end of second amplifier 25 by the 3rd change-over switch 33, and first amplifier 12 constitutes voltage followers.Voltage outputs to lead-out terminal A, and lead-out terminal B is connected on zero level GND (15), is the reference potential output of voltage signal.By Vout=K1*Vref, Vf=Vout, Vp=K2*Vf, Vu=Vp, can obtain outputing to the voltage Vu=K1*K2*Vref between lead-out terminal A and the lead-out terminal B, change the program control input value of the D/A 22 and second amplifier 25, just can change the value of K1 and K2, thereby change the voltage amplitude that outputs between lead-out terminal A and lead-out terminal B.
When device is operated in the frequency output state, the 3rd change-over switch 24 is under the control of program control input, switch between S31 and S32, the output level Vout of D/A 22 and zero level GND are input to the in-phase input end of second amplifier 25 respectively under the effect of the 3rd change-over switch 33.Program-controlled first change-over switch 13 places S12, second change-over switch 14 to place S22, makes first amplifier 12 constitute voltage follower, and voltage outputs to lead-out terminal A.When the 3rd change-over switch 24 places S31,, can obtain outputing to the voltage Vu=K1*K2*Vref between lead-out terminal A and the lead-out terminal B by Vout=K1*Vref, Vf=Vout, Vp=K2*Vf, Vu=Vp; When the 3rd change-over switch 24 places S32,, can obtain outputing to the voltage Vu=0 between lead-out terminal A and lead-out terminal B by Vf=0, Vp=K2*Vf, Vu=Vp.When the program control input value that changes the D/A 22 and second amplifier 25, just can change the value of K1 and K2, thereby change the voltage amplitude that outputs to frequency signal between lead-out terminal A and lead-out terminal B.Simultaneously, change the frequency of the 3rd change-over switch 24 program control inputs, just can change the signal frequency of output.
When circuit working during at the electric current output state, program-controlled the 3rd change-over switch 24 places S31, first change-over switch 13 places S11, second change-over switch 14 to place S21, the output level Vout of D/A 22 is input to the in-phase input end of second amplifier 25 by the 3rd change-over switch 24, and first amplifier 12 constitutes converter.Lead-out terminal C meets voltage source V PP, and its voltage amplitude should be enough to overcome the voltage that current sampling resistor 16 and external load caused to be reduced.When connecing a load between lead-out terminal C and the lead-out terminal D, constant electric current is flowed out by lead-out terminal C, is flowed into by lead-out terminal D.By Vout=K1*Vref, Vf=Vout, Vp=K2*Vf, I=Vp/R, can obtain flowing through electric current I=K1*K2*Vref/R of terminal C and terminal D, change the program control input value of the D/A 22 and second amplifier 25, just can change the value of K1 and K2, thereby change the current amplitude of output.
When circuit working during at simulation Constant Current Load state, program-controlled the 3rd change-over switch 24 places S31, first change-over switch 13 places S11, second change-over switch 14 to place S21, the output level Vout of D/A 22 is input to the in-phase input end of second amplifier 25 by the 3rd change-over switch 24, first amplifier 12 constitutes converter, when between terminal D and the terminal B during external voltage source, electric current is flowed into by terminal D, flow out by terminal B, electric current is constant and the independent from voltage in external voltage source.By Vout=K1*Vref, Vf=Vout, Vp=K2*Vf, I=Vp/R, can obtain flowing through the steady current I=K1*K2*Vref/R of terminal D and terminal B, by changing the program control input value of the D/A 22 and second amplifier 25, just can change the value of K1 and K2, thereby change the steady current amplitude.
From above-mentioned disclosed embodiment as can be known, signal output apparatus can be exported:
(1) all transformable standard-frequency signal of frequency and amplitude;
(2) the adjustable simulation Constant Current Load of constant current value;
(3) the adjustable voltage signal of amplitude;
(4) the adjustable current signal of amplitude.
Because therefore the A wide selection of colours and designs of output signal adopts this signal output apparatus can produce multiple functional portable calibration equipment, instrument check is carried out at the scene of being applicable to, so the present invention also protects the calibration equipment that comprises the disclosed signal output apparatus of art.
More than disclosed only be several specific embodiment of the present invention, but the present invention is not limited thereto, any those skilled in the art can think variation, all should drop on protection scope of the present invention.
Claims (10)
1, a kind of signal output apparatus, it is characterized in that, comprise: signal generation unit, first amplifier, first change-over switch, second change-over switch, MOS, current sampling resistor, lead-out terminal A, lead-out terminal B, lead-out terminal C and lead-out terminal D, wherein:
The signal generation unit is in order to produce voltage signal;
First amplifier, its in-phase input end connect described signal generation unit, and inverting input connects second change-over switch, and output terminal connects first change-over switch;
First change-over switch comprises first switching point and second switching point, and wherein, the output terminal of first switching point connects the grid of MOS, and the output terminal of second switching point connects lead-out terminal A;
Second change-over switch comprises the 3rd switching point and the 4th switching point, and wherein, the output terminal of the 3rd switching point connects the drain electrode of MOS, and the output terminal of the 4th switching point connects lead-out terminal A;
MOS, its source electrode connects lead-out terminal D, its drain electrode by current sampling resistor be connected to lead-out terminal B;
Lead-out terminal C is connected to a power supply.
2, signal output apparatus as claimed in claim 1 is characterized in that, first change-over switch and second change-over switch are programmed switch.
3, signal output apparatus as claimed in claim 2, it is characterized in that, also comprise first controller, described first controller connects the program control input end of first change-over switch and the program control input end of second change-over switch respectively, is used to control first change-over switch in the switching between first switching point and second switching point, the switching of second change-over switch between the 3rd switching point and the 4th switching point.
4, signal output apparatus as claimed in claim 1 is characterized in that, described signal generation unit comprises reference voltage source, D/A and second controller, wherein:
The input end of D/A connects reference voltage source, and its output terminal connects the in-phase input end of described first amplifier;
Second controller connects the program control input end of D/A, is used to control the magnitude of voltage of the output terminal of D/A.
5, signal output apparatus as claimed in claim 4, it is characterized in that, described signal generation unit also comprises second amplifier, connect the D/A and first amplifier respectively, an one input end connects D/A, another input end connects ground, and its output terminal connects the in-phase input end of first amplifier.
6, signal output apparatus as claimed in claim 5, it is characterized in that, described signal generation unit also comprises the 3rd change-over switch that is arranged between the D/A and second amplifier, described the 3rd change-over switch comprises the 5th switching point and the 6th switching point, the input end of the 5th switching point connects the output terminal of D/A, the input end of the 6th switching point connects ground, and the output terminal of described the 3rd change-over switch connects the in-phase input end of second amplifier.
7, signal output apparatus as claimed in claim 6 is characterized in that, described the 3rd change-over switch is a programmed switch, and the program control input end of described the 3rd change-over switch connects second controller, is used to control the output voltage values of the 3rd change-over switch.
As claim 5 or 6 described signal output apparatus, it is characterized in that 8, described second amplifier is a programmable amplifier, described second controller connects the program control input end of second amplifier, is used to control the output valve of second amplifier.
As claim 4 or 8 described signal output apparatus, it is characterized in that 9, described first controller and second controller can be integrated into a controller.
10, signal output apparatus as claimed in claim 9 is characterized in that, described controller is the parts with FPGA (Field Programmable Gate Array) fan-out capability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100535500A CN100336084C (en) | 2005-03-08 | 2005-03-08 | Signal output unit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100535500A CN100336084C (en) | 2005-03-08 | 2005-03-08 | Signal output unit |
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| Publication Number | Publication Date |
|---|---|
| CN1655204A true CN1655204A (en) | 2005-08-17 |
| CN100336084C CN100336084C (en) | 2007-09-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100535500A Expired - Fee Related CN100336084C (en) | 2005-03-08 | 2005-03-08 | Signal output unit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100371960C (en) * | 2005-11-17 | 2008-02-27 | 浙江中控自动化仪表有限公司 | Signal Collecting device |
| CN102128647A (en) * | 2010-12-31 | 2011-07-20 | 浙江中控自动化仪表有限公司 | Self-calibration method of calibration instrument |
| CN104133141A (en) * | 2014-07-30 | 2014-11-05 | 上海镭隆科技发展有限公司 | Load simulation equipment |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2122376U (en) * | 1991-11-23 | 1992-11-18 | 何泽湘 | Integral checking gauge |
| CN2248338Y (en) * | 1995-05-23 | 1997-02-26 | 宫承汉 | Digital multifunctional tester |
| JP3398950B2 (en) * | 1997-11-04 | 2003-04-21 | 横河電機株式会社 | Fieldbus interface circuit |
| CN2590282Y (en) * | 2002-12-03 | 2003-12-03 | 北京安控科技发展有限公司 | Analog quantity output circuit |
-
2005
- 2005-03-08 CN CNB2005100535500A patent/CN100336084C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100371960C (en) * | 2005-11-17 | 2008-02-27 | 浙江中控自动化仪表有限公司 | Signal Collecting device |
| CN102128647A (en) * | 2010-12-31 | 2011-07-20 | 浙江中控自动化仪表有限公司 | Self-calibration method of calibration instrument |
| CN102128647B (en) * | 2010-12-31 | 2012-08-29 | 浙江中控自动化仪表有限公司 | Self-calibration method of calibration instrument |
| CN104133141A (en) * | 2014-07-30 | 2014-11-05 | 上海镭隆科技发展有限公司 | Load simulation equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100336084C (en) | 2007-09-05 |
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