CN209432908U - A kind of PWM duty cycle measurement board - Google Patents
A kind of PWM duty cycle measurement board Download PDFInfo
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- CN209432908U CN209432908U CN201821738934.5U CN201821738934U CN209432908U CN 209432908 U CN209432908 U CN 209432908U CN 201821738934 U CN201821738934 U CN 201821738934U CN 209432908 U CN209432908 U CN 209432908U
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Abstract
The utility model discloses a kind of PWM duty cycles to measure board; it include: the power supply protection circuit for measuring and being arranged on board, the power supply protection circuit includes: first comparator, reference voltage, sampled voltage, the first phase inverter, external power supply, first resistor, second resistance, the first triode, the second capacitor, the tenth resistance and single-chip microcontroller；Cause the power supply protection circuit not work when preventing first diode from damaging in circuit when generating over-current phenomenon avoidance by the double action of first diode and third diode, improves the functional reliability of power supply protection circuit；Continuous to measurement plate clamping in single-chip microcontroller certain time to carry out overcurrent protection after the completion of making overcurrent protection by using the second capacitor, the unsteady current for preventing overcurrent protection from completing moment damages measurement board；The power supply protection circuit realizes the overcurrent protection to measurement board, so that measurement board work is more reliable and more stable, and the power supply protection is novel in design, and job stability is high.
Description
Technical field
The utility model belongs to technical field of data processing, and in particular to a kind of PWM duty cycle measurement board.
Background technique
PWM wave is the adjustable INVENTIONPeriodic digital pulse of duty ratio, is widely used in the fields such as motor control, temperature control.
The key parameter of PWM wave is duty ratio, therefore particularly important to the measurement of PWM duty cycle, in the prior art by data acquisition board
PWM duty cycle measurement board in card realizes the measurement to PWM duty cycle, when PWM duty cycle measures board work, if scene is set
It is standby to generate failure, it is possible to cause the operating current for measuring board excessive, cause to measure burning for board, be unable to complete to PWM
The measurement of duty ratio influences the progress of follow-up work, increases the replacement and maintenance cost of measurement board, thus it is guaranteed that PWM duty
The safety being stuck in than measurement plate under over-current state be very it is necessary to.
Utility model content
To overcome technological deficiency of the existing technology, the utility model discloses a kind of PWM duty cycles to measure board.
Technical solution adopted by the utility model to solve its technical problems is a kind of PWM duty cycles to measure board, comprising:
The power supply protection circuit being arranged on measurement board, the power supply protection circuit include: first comparator, reference voltage, sampling electricity
Pressure, the first phase inverter, external power supply, first resistor, second resistance, the first triode, the second capacitor, first diode, second
Diode, the 4th resistance, third diode, the second comparator, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance,
Two triodes, the tenth resistance and single-chip microcontroller；
The inverting input terminal of the external reference voltage of the non-inverting input terminal of the first comparator, first comparator connects sampling
Voltage, sampled voltage are the voltage measured on the energization input of board and the power supply main line of power supply output end；First comparator
Power end connect external power supply, the ground terminal ground connection of first comparator, the output end of first comparator connects the first phase inverter
Input terminal, the cathode of the output end connection first diode of the first phase inverter, the anode of first diode connects the two or three pole
The collector of the base stage of pipe, the emitter ground connection of the second triode, the second triode connects external power supply by the tenth resistance, the
The collector of two triodes is also connected with the input terminal of single-chip microcontroller, the output end control connection measurement board of single-chip microcontroller；
The output end of first phase inverter is also connected with the first end of first resistor, and the second end of first resistor connects external electricity
Source, the emitter of second end the first triode of connection of first resistor, the grounded collector of the first triode, the first triode
Base stage connects the cathode of first diode by second resistance, and the collector of the first triode is also connected with the same phase of the second comparator
Input terminal, the collector of the first triode also pass through the second capacity earth, and the inverting input terminal of the second comparator passes through the 5th electricity
Resistance connection reference voltage, the power end of the second comparator connect external power supply, and the ground terminal ground connection of the second comparator, second compares
The non-inverting input terminal of device is also connected with the anode of the second diode, and the cathode of the second diode connects the three or two pole by the 4th resistance
The cathode of pipe, the anode of third diode connect the base stage of the second triode, and one end of the 5th resistance passes through the be sequentially connected in series
The anode of six resistance, the 7th resistance and the 8th resistance connection third diode, the output end of the second comparator connect the second reverse phase
The input terminal of device, the output end of the second phase inverter are separately connected common end and the third diode of the 6th resistance and the 7th resistance
Cathode.
Preferably, 3rd resistor is also connected between the collector and ground of first triode, and 3rd resistor is in parallel
It is connected to the second capacitor both ends.
Preferably, the 9th resistance is connected between the third diode and the base stage of the second triode.
Preferably, the power end of the first comparator is also grounded by first capacitor.
Preferably, the sampled voltage is connected with sample circuit, and the sample circuit includes: inductance, third capacitor, the tenth
One resistance and twelfth resistor；Inductance, the second end of inductance are connected on the power supply main line of energization input and power supply output end
By third capacity earth, the second end of inductance also passes through the eleventh resistor of series connection and twelfth resistor is grounded, and the tenth
The common end of one resistance and twelfth resistor exports sampled voltage.
Preferably, the chip model that the first comparator and the second comparator use is LM193.
The beneficial effects of the utility model are: passing through the double action of first diode and third diode, generating
Cause the power supply protection circuit not work when flow phenomenon, when preventing first diode from damaging in circuit, improves power supply protection
The functional reliability of circuit；After the completion of making overcurrent protection by using the second capacitor, to measurement plate in single-chip microcontroller certain time
Clamping is continuous to carry out overcurrent protection, and the unsteady current for preventing overcurrent protection from completing moment damages measurement board, causes not
Repairable loss；The power supply protection circuit realizes the overcurrent protection to measurement board, so that measurement board work is more steady
It is fixed reliable, and the power supply protection is novel in design, job stability is high, and structure is simple.
Detailed description of the invention
Fig. 1 is the circuit diagram of power supply protection circuit described in the utility model.
Appended drawing reference: ub- sampled voltage, uc- reference voltage, U1- first comparator, C1- first capacitor, F1- first are anti-
Phase device, VCC- external power supply, R1- first resistor, R2- second resistance, T1- the first triode R3- 3rd resistor, the second electricity of C2-
Hold, the second diode of D2-, the 4th resistance of R4-, D3- third diode, the second comparator of U2-, the second phase inverter of F2-, R5- the
Five resistance, the 6th resistance of R6-, the 7th resistance of R7-, the 8th resistance of R8-, the 9th resistance of R9-, the second triode of T2-, R10- the tenth
Resistance, L- inductance, R11- eleventh resistor, R12- twelfth resistor, C3- third capacitor.
Specific embodiment
More detailed description is done to the embodiments of the present invention below in conjunction with attached drawing and appended drawing reference, makes to be familiar with ability
The technology people in domain can implement accordingly after studying this specification carefully.It should be appreciated that specific embodiment described herein is only to solve
The utility model is released, is not used to limit the utility model.
A kind of PWM duty cycle measurement board, it is characterised in that: include: the power supply protection circuit for measuring and being arranged on board, institute
Stating power supply protection circuit includes: first comparator U1, reference voltage uc, sampled voltage ub, the first phase inverter F1, external power supply
VCC, first resistor R1, second resistance R2, the first triode T1, the second capacitor C2, first diode D1, the second diode D2,
4th resistance R4, third diode D3, the second comparator U2, the second phase inverter F2, the 5th resistance R5, the 6th resistance R6, the 7th
Resistance R7, the 8th resistance R8, the second triode T2, the tenth resistance R10 and single-chip microcontroller；
The inverting input terminal of the non-inverting input terminal of the first comparator U1 external reference voltage uc, first comparator U1 connect
Sampled voltage ub is met, sampled voltage ub is the voltage measured on the energization input of board and the power supply main line of power supply output end；
The power end of first comparator U1 connects external power supply VCC, and the ground terminal ground connection of first comparator U1, first comparator U1's is defeated
The input terminal of the first phase inverter F1 of outlet connection, the cathode of the output end connection first diode D1 of the first phase inverter F1, first
The anode of diode D1 connects the base stage of the second triode T2, and the emitter of the second triode T2 is grounded, the second triode T2's
Collector is also connected with the input of single-chip microcontroller by the collector of the tenth resistance R10 connection external power supply VCC, the second triode T2
End, the output end control connection measurement board of single-chip microcontroller；
The output end of first phase inverter F1 is also connected with the first end of first resistor R1, and the second end connection of first resistor R1 is outer
Power supply VCC is met, the second end of first resistor R1 connects the emitter of the first triode T1, and the collector of the first triode T1 connects
Ground, the base stage of the first triode T1 pass through the cathode of second resistance R2 connection first diode D1, the current collection of the first triode T1
Pole is also connected with the non-inverting input terminal of the second comparator U2, and the collector of the first triode T1 also passes through the second capacitor C2 ground connection, the
The inverting input terminal of two comparator U2 is outer by the power end connection of the 5th resistance R5 connection reference voltage uc, the second comparator U2
Power supply VCC, the ground terminal ground connection of the second comparator U2 are met, the non-inverting input terminal of the second comparator U2 is also connected with the second diode D2
Anode, the cathode of the second diode D2 passes through the cathode of the 4th resistance R4 connection third diode D3, third diode D3's
Anode connects the base stage of the second triode T2, and one end of the 5th resistance R5 passes through the 6th resistance R6, the 7th resistance that are sequentially connected in series
The output end of the anode of R7 and the 8th resistance R8 connection third diode D3, the second comparator U2 connects the defeated of the second phase inverter F2
Enter end, the output end of the second phase inverter F2 is separately connected common end and the third diode of the 6th resistance R6 and the 7th resistance R7
Cathode D3；
Specifically, the working principle of the power supply protection circuit are as follows: sampled voltage ub is the power supply of duty ratio measuring board
The voltage value that acquires on power supply main line between input terminal and power supply output end, if when generation over-current phenomenon avoidance, sampled voltage at this time
Ub value increases, and sampled voltage ub value is greater than reference voltage uc value, and reference voltage uc is corresponding voltage threshold when generating over-current phenomenon avoidance
Value, the voltage value of first comparator U1 non-inverting input terminal is greater than the voltage value of inverting input terminal, first comparator U1 output at this time
High level signal, high level signal is converted to low level signal by the first phase inverter F1 and exports, at this point, first diode D1 connects
Low level signal conducting is received, the base voltage of the second triode T2 is pulled low at this time, and the second triode T2 is NPN type triode,
Second triode T2 receives low level signal cut-off, and single-chip microcontroller is connected to the height of external power supply VCC by the tenth resistance R10 at this time
Voltage signal, single-chip microcontroller receive control measurement board after the control signal of high voltage signal for electrically disconnected, realize to measurement plate
The overcurrent protection of card；
Simultaneously as over-current phenomenon avoidance, the first triode T1 saturation conduction, at this point, the non-inverting input terminal of the second comparator U2
The high voltage of external power supply VCC is directly connected to by the first triode T1 of conducting, the non-inverting input terminal of the second comparator U2
Voltage value is greater than the voltage value of inverting input terminal, and the second comparator U2 exports high level signal, and high level signal is anti-by second
Phase device F2 is converted to low level signal output, and the second triode T2 receives low level signal cut-off at this time, and single-chip microcontroller passes through the tenth
Resistance R10 is connected to the high voltage signal of external power supply VCC, controls measurement after the control signal of single-chip microcontroller reception high voltage signal
Board for electrically disconnected, realize the overcurrent protection to measurement board；
Wherein, the second capacitor C2 charges when the first triode T1 is connected, and external power supply VCC is straight when due to conducting
It connects and is loaded on the second capacitor C2, the second capacitor C2 moment completed charging, after the overcurrent protection movement of single-chip microcontroller is completed, greatly
Electric current pop-off, the low level signal of first comparator U1 output at this time, the first phase inverter F1 output high level signal, the one or three
Pole pipe T1 is disconnected, and the second capacitor C2 stops charging, but the voltage on the second capacitor C2 will not be mutated, therefore, the second comparator U2
High level signal is still exported, the second phase inverter F2 exports low level signal, and the second triode T2 cut-off, single-chip microcontroller is to measurement plate
Clamping is continuous to carry out overcurrent protection, the discharge paths that the second diode D2 and the 4th resistance R4 are the second capacitor C2, when the second capacitor
When the tension discharge of C2 is to the reference voltage uc for being lower than the second comparator U2 inverting input terminal, the second comparator U2 exports low level
Signal, the second phase inverter F2 export high level signal, and high level signal passes through the 7th resistance R7, the 8th resistance R8 and the 9th resistance
The branch of R9 is loaded onto the base stage of the second triode T2, is grounded since the second triode T2 is connected, single-chip microcontroller receives low electricity at this time
Ordinary mail number does not carry out power-off control to the power supply of measurement board, is at this time electric current normal condition；
Pass through the double action of first diode D1 and third diode D3, when generating over-current phenomenon avoidance, first diode
Two branches of D1 and third diode D3 provide low level signal for the second triode T2, prevent first diode D1 in circuit
Cause the power supply protection circuit not work when middle damage, improves the functional reliability of power supply protection circuit；Second is used simultaneously
It is continuous to measurement plate clamping in single-chip microcontroller certain time to carry out overcurrent protection after the completion of capacitor C2 makes overcurrent protection, prevent overcurrent
The unsteady current that moment is completed in protection damages measurement board, causes irremediable loss, reduces measurement board
Maintenance and replacement cost；The overcurrent protection to measurement board is realized by the power supply protection circuit, so that measurement board work
It is more reliable and more stable, and the power supply protection is novel in design, job stability is high, and structure is simple.
3rd resistor R3 is also connected between the collector and ground of the first triode T1, and 3rd resistor R3 parallel connection connects
It connects at the second both ends capacitor C2；When the 3rd resistor R3 is for preventing the first triode T1 from turning off, have on the first triode T1
Faint leakage current charges to the second capacitor C2.
The 9th resistance R9 is connected between the third diode D3 and the base stage of the second triode T2；9th resistance
R9 is current-limiting resistance, guarantees circuit job stability, improves circuit reliability.
The power end of the first comparator U1 also passes through first capacitor C1 and is grounded；First capacitor C1 guarantees first comparator
The voltage of U1 power end will not be mutated, and keep stablizing.
The sampled voltage ub is connected with sample circuit, and the sample circuit includes: inductance L, third capacitor C3, the 11st
Resistance R11 and twelfth resistor R12；It is connected with inductance L on the power supply main line of energization input and power supply output end, inductance L's
Second end is grounded by third capacitor C3, and the second end of inductance L also passes through the electricity of eleventh resistor R11 and the 12nd of series connection
Hinder R12 ground connection, the common end output sampled voltage ub of eleventh resistor R11 and twelfth resistor R12；The inductance L and third
Capacitor C3 plays preliminary pressure stabilizing and filter action, so that subsequent output voltage is more stable, the electricity of eleventh resistor R11 and the 12nd
Resistance R12 obtains sampled voltage using series connection partial pressure, and the sample mode is simply effective, increases inductance L before collection voltages of connecting
Make sampled voltage ub more stable with third capacitor C3.
The chip model that the first comparator and the second comparator use is LM193；LM193 has low-power consumption, sensitive
Spend high advantage.
The above content is the further descriptions made in conjunction with specific preferred embodiment to the utility model, cannot recognize
Determine specific embodiment of the present utility model to be only limited to these instructions.For the common skill of the utility model technical field
For art personnel, the other embodiments obtained in the case where not departing from the technical solution of the utility model be should be included in practical
In novel protection scope.
Claims (6)
1. a kind of PWM duty cycle measures board, it is characterised in that: it include: the power supply protection circuit for measuring and being arranged on board, it is described
Power supply protection circuit includes: first comparator, reference voltage, sampled voltage, the first phase inverter, external power supply, first resistor,
Two resistance, the first triode, the second capacitor, first diode, the second diode, the 4th resistance, third diode, second are compared
Device, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, the second triode, the tenth resistance and single-chip microcontroller；
The external reference voltage of the non-inverting input terminal of the first comparator, the inverting input terminal connection sampling electricity of first comparator
Pressure, sampled voltage are the voltage measured on the energization input of board and the power supply main line of power supply output end；First comparator
Power end connects external power supply, the ground terminal ground connection of first comparator, and the output end of first comparator connects the first phase inverter
Input terminal, the cathode of the output end connection first diode of the first phase inverter, the anode of first diode connect the second triode
Base stage, the emitter ground connection of the second triode, the collector of the second triode connects external power supply by the tenth resistance, second
The collector of triode is also connected with the input terminal of single-chip microcontroller, the output end control connection measurement board of single-chip microcontroller；
The output end of first phase inverter is also connected with the first end of first resistor, and the second end of first resistor connects external power supply, the
The second end of one resistance connects the emitter of the first triode, the grounded collector of the first triode, the base stage of the first triode
The cathode of first diode is connected by second resistance, the collector of the first triode is also connected with the homophase input of the second comparator
End, the collector of the first triode also pass through the second capacity earth, and the inverting input terminal of the second comparator is connected by the 5th resistance
Reference voltage is connect, the power end of the second comparator connects external power supply, and the ground terminal of the second comparator is grounded, the second comparator
Non-inverting input terminal is also connected with the anode of the second diode, and the cathode of the second diode connects third diode by the 4th resistance
Cathode, the anode of third diode connect the base stage of the second triode, and one end of the 5th resistance passes through the 6th electricity being sequentially connected in series
Resistance, the 7th resistance and the 8th resistance connect the anode of third diode, and the output end of the second comparator connects the second phase inverter
Input terminal, the output end of the second phase inverter are separately connected the common end of the 6th resistance and the 7th resistance and the yin of third diode
Pole.
2. a kind of PWM duty cycle as described in claim 1 measures board, it is characterised in that: the current collection of first triode
3rd resistor is also connected between pole and ground, and 3rd resistor is connected in the second capacitor both ends in parallel.
3. a kind of PWM duty cycle as described in claim 1 measures board, it is characterised in that: the third diode and second
The 9th resistance is connected between the base stage of triode.
4. a kind of PWM duty cycle as described in claim 1 measures board, it is characterised in that: the power supply of the first comparator
End is also grounded by first capacitor.
5. a kind of PWM duty cycle as described in claim 1 measures board, it is characterised in that: the sampled voltage, which is connected with, to be adopted
Sample circuit, the sample circuit include: inductance, third capacitor, eleventh resistor and twelfth resistor；Energization input and power supply
Inductance is connected on the power supply main line of output end, by third capacity earth, the second end of inductance also passes through the second end of inductance
The eleventh resistor and twelfth resistor of series connection are grounded, the common end output sampling electricity of eleventh resistor and twelfth resistor
Pressure.
6. a kind of PWM duty cycle as described in claim 1 measures board, it is characterised in that: the first comparator and second
The chip model that comparator uses is LM193.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821738934.5U CN209432908U (en) | 2018-10-25 | 2018-10-25 | A kind of PWM duty cycle measurement board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821738934.5U CN209432908U (en) | 2018-10-25 | 2018-10-25 | A kind of PWM duty cycle measurement board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209432908U true CN209432908U (en) | 2019-09-24 |
Family
ID=67966502
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821738934.5U Active CN209432908U (en) | 2018-10-25 | 2018-10-25 | A kind of PWM duty cycle measurement board |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209432908U (en) |
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2018
- 2018-10-25 CN CN201821738934.5U patent/CN209432908U/en active Active
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