CN210119720U - Adjustable constant current source circuit - Google Patents
Adjustable constant current source circuit Download PDFInfo
- Publication number
- CN210119720U CN210119720U CN201921189513.6U CN201921189513U CN210119720U CN 210119720 U CN210119720 U CN 210119720U CN 201921189513 U CN201921189513 U CN 201921189513U CN 210119720 U CN210119720 U CN 210119720U
- Authority
- CN
- China
- Prior art keywords
- voltage
- current
- resistor
- output
- circuit
- 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
Landscapes
- Control Of Voltage And Current In General (AREA)
Abstract
The utility model discloses an adjustable constant current source circuit, which comprises a programmable logic device, a digital-to-analog converter and a voltage-to-current converter; the programmable logic device is used for controlling the output voltage of the digital-to-analog converter; the digital-to-analog converter is used for converting a digital signal sent by the programmable logic device into an output voltage and sending the output voltage to the voltage-to-current converter; and the voltage-current converter is used for converting the output voltage of the digital-analog converter into constant current and supplying power to the equipment to be powered. The utility model discloses a programmable logic device is as the controller to digital-to-analog converter, the voltage-to-current converter integrated device design constant current source of high accuracy, and output range is adjustable, can satisfy different occasion application requirements, just the utility model discloses a traditional design shortcoming is abandoned to the method, has the characteristics that the precision is high, stability is strong.
Description
Technical Field
The utility model relates to a constant current source circuit specifically is an adjustable constant current source circuit.
Background
The constant current source is also called as a current stabilizing source, is a wide-frequency-spectrum high-precision alternating current and current stabilizing power supply, and has the advantages of high response speed, high constant current precision, capability of working stably for a long time, suitability for various loads and the like. The device is mainly used for detecting thermal relays, molded case circuit breakers, small-sized short-circuit devices and production occasions needing setting of rated current, action current, short-circuit protection current and the like.
The traditional constant current source mostly adopts an analog circuit design and an independent transistor design, and the device is influenced to a greater extent under the environments of high temperature, low temperature and large noise, so that the output is unstable and the precision is reduced; meanwhile, in a military environment, the requirements are stricter.
Therefore, an adjustable constant current source circuit is provided, and the output current can be adjusted according to the use environment, so that the use requirement under different conditions is met.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide an adjustable constant current source circuit to avoid among the analog circuit transistor to receive the environmental impact to make and the problem that precision reduction and stability were cut down.
In order to achieve the above object, the utility model provides a following technical scheme:
an adjustable constant current source circuit comprises a programmable logic device, a digital-to-analog converter and a voltage-to-current converter;
the programmable logic device is used for controlling the output voltage of the digital-to-analog converter;
the digital-to-analog converter is used for converting a digital signal sent by the programmable logic device into an output voltage and sending the output voltage to the voltage-to-current converter;
the voltage-current converter is used for converting the output voltage of the digital-analog converter into constant current and supplying power to equipment to be powered;
the voltage-current converter comprises a current conversion circuit, an output current monitoring circuit and an interface protection circuit which are connected in sequence;
the output current monitoring circuit comprises a P-channel enhancement type MOSFET Q1, a PNP type triode Q2 and a resistor R89;
the drain electrode of the P-channel enhancement type MOSFET Q1 IS connected with one end of a resistor R89 and the base electrode of a PNP type triode Q2, the other end of the resistor R89 IS connected with the collector electrode of the PNP type triode Q2 and then IS connected with the output end IS of the voltage-current converter, the grid electrode of the P-channel enhancement type MOSFET Q1 IS connected with the emitter electrode of the PNP type triode Q2 and then IS connected with the output end VG of the voltage-current converter, and the source electrode of the P-channel enhancement type MOSFET Q1 IS connected with an interface protection circuit.
In the scheme, the programmable logic device is bidirectionally connected with the digital-to-analog converter, code programming is carried out through the programmable logic device so as to configure the output voltage of the digital-to-analog converter, different voltages can be obtained according to requirements, the digital-to-analog converter feeds information back to the programmable logic device so as to realize continuous control of the programmable logic device, and the digital-to-analog converter is connected with the voltage-to-current converter; the voltage-current converter outputs corresponding current according to the output voltage of the digital-analog converter, and further can obtain different currents according to requirements. Therefore the utility model discloses can export the constant current that has broad range, stable and high accuracy to satisfy different application scene demands. The voltage-current converter can be protected by the output current monitoring circuit and the interface protection circuit.
The scheme also discloses a specific structure and a connection mode of the output current monitoring circuit, wherein Q2 IS a PNP type triode, IS and R89 generate Q2 base bias current, an emitter of Q2 IS connected with a grid of Q1, collector current of Q2 IS IS, and Q2 IS conducted after the base generates bias current; q1 is P channel enhancement MOSFET, the grid voltage is greater than the drain and then the voltage is conducted, when Q2 works in the amplification state, the collector voltage is less than the base voltage, then the grid voltage of Q1 is less than the drain voltage, then Q1 is conducted, then the source generates the current output. The VG pin is used for detecting the current change state, feeding back to the inside of the chip and protecting the chip under abnormal conditions.
As a further aspect of the present invention: the model of the programmable logic device is EP4CE6E22I7, the model of the digital-to-analog converter is TLV5617AID, the model of the voltage-to-current converter is XTR111, and the equipment to be powered is an IEPE piezoelectric vibration sensor.
The scheme provides the specific models of the components, thereby being convenient to implement.
As a further aspect of the present invention: the interface protection circuit comprises a rectifying filter capacitor C116, a Schottky diode V2, a voltage stabilizing diode V3 and a current limiting resistor R90;
the source electrode of the P-channel enhancement type MOSFET Q1 is respectively connected with the rectifying and filtering capacitor C116, the anode of the Schottky diode V2 and the current-limiting resistor R90, the other end of the rectifying and filtering capacitor C116 is grounded, the cathode of the Schottky diode V2 is connected with the voltage +24V, the other end of the current-limiting resistor R90 is respectively connected with the cathode of the voltage stabilizing diode V3 and the input end IN _ A of the equipment to be powered, and the anode of the voltage stabilizing diode V3 is grounded.
In the scheme, a Schottky diode V2 is designed at an interface part of the voltage-current converter to clamp the voltage at the maximum DC24V, C116 is output filtering, R90 is an output current-limiting resistor, and V3 plays a role in interface voltage stabilization protection, so that the partial circuit not only protects an output interface of the voltage-current converter, but also protects an interface of equipment to be powered.
As a further aspect of the present invention: and the interface of the equipment to be powered is connected with an input current monitoring circuit.
The part realizes the constant current source signal state monitoring and the protection of the interface of the equipment to be powered under the abnormal condition.
As a further aspect of the present invention: the input current monitoring circuit comprises operational amplifiers N3A and N3B, current limiting resistors R3 and R10, resistors R1, R5, R12, R2 and R9, capacitors C2 and C4 and a control device;
the output end of the equipment to be powered is connected with the inverting input end of an operational amplifier N3A through a current-limiting resistor R3 and is connected with the non-inverting input end of an operational amplifier N3B through a current-limiting resistor R10, the non-inverting input end of an operational amplifier N3A is respectively connected with a resistor R5, a resistor R1 and a parallel circuit of a capacitor C2 and a capacitor C4, the other end of the parallel circuit of the capacitors C2 and C4 is grounded, the inverting input end of the operational amplifier N3B is respectively connected with the other end of a resistor R5 and a resistor R12, the other end of the resistor R1 is connected with a voltage +24V, the other end of the resistor R12 is grounded, the output end of the operational amplifier N3A is connected with a resistor R2 and a monitoring input end of a control device, the output end of the operational amplifier N3B is connected with the resistor R9 and the monitoring input end of the control device, the resistor R2 and the other end of the resistor R9 are connected with.
The scheme mainly comprises the steps of detecting the open circuit of the interface of the equipment to be powered and detecting the short circuit of the interface.
a) R1, R5 and R12 generate comparison threshold voltage of an open circuit and short circuit detection circuit, the input of the non-inverting input end of the operational amplifier N3A is the comparison threshold voltage input of open circuit detection, and the input of the inverting input end is the signal input of a monitoring port; the reverse phase input end of the N3B operational amplifier is used for inputting the comparison threshold voltage of short circuit detection, and the non-phase input end is used for inputting a monitoring port signal;
b) the output end of the N3A is an open circuit monitoring output port, and when the interface is in a normal state, the voltage of the inverting input end of the N3A is greater than that of the non-inverting input end, the output end is in a low level, and the output end is in a high level if the output end is abnormal;
c) the output end of N3B is a short circuit monitoring output port, and when the interface is in a normal state, the voltage of the non-inverting input end of N3B should be greater than that of the inverting input end, the output end outputs high voltage, and the abnormality is low level;
d) the monitoring input end of the control device monitors input signals, monitors signal level in real time, and closes the output of the digital-analog converter through the programmable logic device when abnormality occurs, so as to form self protection.
As a further aspect of the present invention: and a UART interface is reserved on the programmable logic device.
And a UART interface is reserved, and the host can realize output control of the constant current circuit.
The utility model has the advantages that: the utility model provides an adjustable constant current source circuit, (1) adopt the programmable logic device as the controller, design the constant current source with digital analog converter, voltage current converter integrated device of high accuracy, and output range is adjustable, can satisfy different occasion application requirements;
(2) the circuit adopts digital integrated device, and independent transistor design is adopted more in traditional design, and analog circuit receives the environmental impact great, and output accuracy and stability are lower, and the utility model discloses a traditional design shortcoming is abandoned to the method, has the characteristics that the precision is high, stability is strong.
Drawings
FIG. 1 is a schematic diagram of the present invention;
fig. 3 is a circuit diagram of the medium voltage-current converter of the present invention;
fig. 4 is a circuit for monitoring input current in the present invention;
fig. 5 is a circuit diagram of the controller N19F according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying 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.
Referring to fig. 1-3, an adjustable constant current source circuit includes a programmable logic device, a digital-to-analog converter, and a voltage-to-current converter;
the programmable logic device is used for controlling the output voltage of the digital-to-analog converter;
the digital-to-analog converter is used for converting a digital signal sent by the programmable logic device into an output voltage and sending the output voltage to the voltage-to-current converter;
and the voltage-current converter is used for converting the output voltage of the digital-analog converter into constant current and supplying power to the equipment to be powered.
Preferably, referring to fig. 2, the programmable logic device is of a model number EP4CE6E22I7, N19B chip; the model of the digital-to-analog converter is TLV5617AID and is an N17 chip; referring to fig. 3, the voltage-current converter is model XTR111, which is a U2 chip; the equipment to be powered is an IEPE piezoelectric vibration sensor.
Referring to fig. 2, the N19B chip and the N17 chip are connected in a bi-directional manner by using a standard SPI communication interface, the interface clock is 20MHz at maximum, and the refresh frequency is 1.25MHz at maximum, so that the communication and update rates can completely meet the application requirements; the pin 30 of the N19B chip is connected with the input DIN of the N17 chip through a resistor R142, the pin 31 of the N19B chip is connected with the input SCLK of the N17 chip through a resistor R142, and the pin 30 of the N19B chip is connected with the input CS of the N17 chip through a resistor R143, so that external signal interference can be reduced and signal quality can be improved.
Referring to fig. 2, VIN _ a and VIN _ B of N17 are two voltage output interfaces, and the two outputs are independent from each other; REF _2.048V is a reference voltage input; the VDD output terminal of N17 is connected to +3.3V and the capacitor C118, the other terminal of the capacitor C118 is grounded, and the AGND output terminal is grounded.
Referring to fig. 3, the output terminal VSP of XTR111 is connected to +2.4V and the capacitor C114, respectively, the other end of the capacitor C114 is grounded, and the output terminals GEGS and REGF of XTR111 are connected to each other; the input end VIN of the XTR111 is connected to the VIN _ a end of the N17 through a resistor R92, the input end RSET end of the XTR111 is grounded through a resistor RSET, the CUR _ CTR signal at the input end OD end of the XTR111 is at a low level, the input end OD end of the XTR111 is connected to the control device N19F, so as to realize the output closing and opening control function, and the input end GND end of the XTR111 is grounded.
Preferably, referring to fig. 3, the voltage-to-current converter includes a current converting circuit, an output current monitoring circuit, and an interface protection circuit, which are connected in sequence.
Preferably, the output current monitoring circuit comprises a P-channel enhancement type MOSFET Q1, a PNP type triode Q2 and a resistor R89;
the drain electrode of the P-channel enhancement type MOSFET Q1 IS connected with one end of a resistor R89 and the base electrode of a PNP type triode Q2, the other end of the resistor R89 IS connected with the collector electrode of the PNP type triode Q2 and then IS connected with the output end IS of the voltage-current converter, the grid electrode of the P-channel enhancement type MOSFET Q1 IS connected with the emitter electrode of the PNP type triode Q2 and then IS connected with the output end VG of the voltage-current converter, and the source electrode of the P-channel enhancement type MOSFET Q1 IS connected with an interface protection circuit
Preferably, the interface protection circuit comprises a rectifying filter capacitor C116, a schottky diode V2, a zener diode V3 and a current limiting resistor R90;
the source electrode of the P-channel enhancement type MOSFET Q1 is respectively connected with the rectifying and filtering capacitor C116, the anode of the Schottky diode V2 and the current-limiting resistor R90, the other end of the rectifying and filtering capacitor C116 is grounded, the cathode of the Schottky diode V2 is connected with the voltage +24V, the other end of the current-limiting resistor R90 is respectively connected with the cathode of the voltage stabilizing diode V3 and the input end IN _ A of the equipment to be powered, and the anode of the voltage stabilizing diode V3 is grounded.
Preferably, referring to fig. 4, an input current monitoring circuit is connected to the interface of the device to be powered.
Preferably, the input current monitoring circuit comprises operational amplifiers N3A and N3B, current limiting resistors R3 and R10, resistors R1, R5, R12, R2 and R9, capacitors C2 and C4 and a control device; this control device is shown as N19I.
The output end of the equipment to be powered is connected with the inverting input end of an operational amplifier N3A through a current-limiting resistor R3 and is connected with the non-inverting input end of an operational amplifier N3B through a current-limiting resistor R10, the non-inverting input end of an operational amplifier N3A is respectively connected with a resistor R5, a resistor R1 and a parallel circuit of a capacitor C2 and a capacitor C4, the other end of the parallel circuit of the capacitors C2 and C4 is grounded, the inverting input end of the operational amplifier N3B is respectively connected with the other end of a resistor R5 and a resistor R12, the other end of the resistor R1 is connected with a voltage +24V, the other end of the resistor R12 is grounded, the output end of the operational amplifier N3A is connected with a resistor R2 and a monitoring input end of a control device, the output end of the operational amplifier N3B is connected with the resistor R9 and the monitoring input end of the control device, the resistor R2 and the other end of the resistor R9 are connected with.
The output of U2 IN fig. 3 is IN _ a, the output of U2 is the operating excitation source of the IEPE piezoelectric vibration sensor, and the sensor is a single wire system, the vibration signal generated is output through the single wire, and IN _ a IN fig. 4 is the voltage signal generated by the sensor.
Preferably, referring to fig. 1, the programmable logic device reserves a UART interface.
It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (6)
1. An adjustable constant current source circuit is characterized by comprising a programmable logic device, a digital-to-analog converter and a voltage-to-current converter;
the programmable logic device is used for controlling the output voltage of the digital-to-analog converter;
the digital-to-analog converter is used for converting a digital signal sent by the programmable logic device into an output voltage and sending the output voltage to the voltage-to-current converter;
the voltage-current converter is used for converting the output voltage of the digital-analog converter into constant current and supplying power to equipment to be powered;
the voltage-current converter comprises a current conversion circuit, an output current monitoring circuit and an interface protection circuit which are connected in sequence;
the output current monitoring circuit comprises a P-channel enhancement type MOSFET Q1, a PNP type triode Q2 and a resistor R89;
the drain electrode of the P-channel enhancement type MOSFET Q1 IS connected with one end of a resistor R89 and the base electrode of a PNP type triode Q2, the other end of the resistor R89 IS connected with the collector electrode of the PNP type triode Q2 and then IS connected with the output end IS of the voltage-current converter, the grid electrode of the P-channel enhancement type MOSFET Q1 IS connected with the emitter electrode of the PNP type triode Q2 and then IS connected with the output end VG of the voltage-current converter, and the source electrode of the P-channel enhancement type MOSFET Q1 IS connected with an interface protection circuit.
2. The adjustable constant current source circuit of claim 1, wherein the programmable logic device is of a type EP4CE6E22I7, the digital-to-analog converter is of a type TLV5617AID, the voltage-to-current converter is of a type XTR111, and the device to be powered is an IEPE piezoelectric vibration sensor.
3. The adjustable constant current source circuit as claimed in claim 1, wherein the interface protection circuit comprises a rectifying filter capacitor C116, a schottky diode V2, a zener diode V3, and a current limiting resistor R90;
the source electrode of the P-channel enhancement type MOSFET Q1 is respectively connected with the rectifying and filtering capacitor C116, the anode of the Schottky diode V2 and the current-limiting resistor R90, the other end of the rectifying and filtering capacitor C116 is grounded, the cathode of the Schottky diode V2 is connected with the voltage +24V, the other end of the current-limiting resistor R90 is respectively connected with the cathode of the voltage stabilizing diode V3 and the input end IN _ A of the equipment to be powered, and the anode of the voltage stabilizing diode V3 is grounded.
4. The adjustable constant current source circuit of claim 1, wherein an input current monitoring circuit is connected to the interface of the device to be powered.
5. The adjustable constant current source circuit as claimed in claim 4, wherein the input current monitoring circuit comprises operational amplifiers N3A and N3B, current limiting resistors R3 and R10, resistors R1, R5, R12, R2 and R9, capacitors C2 and C4 and a control device;
the output end of the equipment to be powered is connected with the inverting input end of an operational amplifier N3A through a current-limiting resistor R3 and is connected with the non-inverting input end of an operational amplifier N3B through a current-limiting resistor R10, the non-inverting input end of an operational amplifier N3A is respectively connected with a resistor R5, a resistor R1 and a parallel circuit of a capacitor C2 and a capacitor C4, the other end of the parallel circuit of the capacitors C2 and C4 is grounded, the inverting input end of the operational amplifier N3B is respectively connected with the other end of a resistor R5 and a resistor R12, the other end of the resistor R1 is connected with a voltage +24V, the other end of the resistor R12 is grounded, the output end of the operational amplifier N3A is connected with a resistor R2 and a monitoring input end of a control device, the output end of the operational amplifier N3B is connected with the resistor R9 and the monitoring input end of the control device, the resistor R2 and the other end of the resistor R9 are connected with.
6. The adjustable constant current source circuit of claim 1, wherein the programmable logic device is reserved with a UART interface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921189513.6U CN210119720U (en) | 2019-07-25 | 2019-07-25 | Adjustable constant current source circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921189513.6U CN210119720U (en) | 2019-07-25 | 2019-07-25 | Adjustable constant current source circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210119720U true CN210119720U (en) | 2020-02-28 |
Family
ID=69616903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921189513.6U Active CN210119720U (en) | 2019-07-25 | 2019-07-25 | Adjustable constant current source circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210119720U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114966109A (en) * | 2022-05-19 | 2022-08-30 | 武汉港迪技术股份有限公司 | Two-wire system IEPE acceleration sensor detection system and power supply circuit |
-
2019
- 2019-07-25 CN CN201921189513.6U patent/CN210119720U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114966109A (en) * | 2022-05-19 | 2022-08-30 | 武汉港迪技术股份有限公司 | Two-wire system IEPE acceleration sensor detection system and power supply circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102111070B (en) | The regulator over-voltage protection circuit that standby current reduces | |
| CN105446403A (en) | Low dropout linear voltage regulator | |
| CN101872207A (en) | Voltage modulator circuit | |
| CN103219893B (en) | Switch power controller and switching power circuit | |
| CN202856607U (en) | Control circuit and switching converter | |
| CN104283430A (en) | Soft start switching power supply conversion device | |
| CN102801310B (en) | Direct-current switch power supply circuit | |
| CN210119720U (en) | Adjustable constant current source circuit | |
| CN104734498A (en) | DC-DC voltage rising module and voltage rising module overvoltage protection circuit | |
| CN216086450U (en) | Distribution switch circuit who possesses current sampling and voltage sampling | |
| CN101364797B (en) | Active voltage clamping grid driver circuit | |
| CN104852563A (en) | Switching power supply external soft start circuit | |
| CN105846663B (en) | Operating system and control method | |
| CN210351116U (en) | Time delay control circuit | |
| CN215526488U (en) | Constant current source circuit | |
| CN107422773B (en) | Digital low-dropout regulator | |
| CN205142005U (en) | PWM pressure regulating circuit and constant voltage source circuit | |
| CN213521351U (en) | Bus power supply circuit and system | |
| CN112542818B (en) | Input undervoltage protection circuit and power panel comprising same | |
| CN210405097U (en) | Wide voltage range DC input switch power supply | |
| CN210037954U (en) | Power supply voltage overvoltage and undervoltage protection indicating circuit | |
| CN102035181A (en) | Overcurrent and overvoltage protection circuit in switch power supply | |
| CN212012132U (en) | High-voltage input overvoltage and undervoltage protection circuit | |
| CN206481039U (en) | Overvoltage crowbar and load voltage regulation circuit | |
| CN211377894U (en) | Power supply device capable of remotely adjusting power |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |