Summary of the invention
The present invention is at least one defect overcoming described in above-mentioned prior art, and a kind of electric double layer super capacitor cubic content measurement circuit is provided, and its circuit connects simple, and cost is lower, widespread use on a large scale.Further, provide the measuring method of this circuit of application, its measuring method step is succinct.
For solving the problems of the technologies described above, the technical solution used in the present invention is: a kind of electric double layer super capacitor cubic content measurement circuit, wherein, comprise timer, the first voltage comparator being connected with timer, second voltage comparer, also comprise constant current source, constant-current discharge circuit, switch, constant current source is connected with the first voltage comparator, second voltage comparer respectively, testing capacitor one end ground connection, other end connecting valve, the A end connection constant current source of switch is for testing capacitor is charged, and the B end of switch connects constant-current discharge circuit and is used for capacitor discharge to be measured.
In this programme, the electric current syndeton of metering circuit is simple, and timer can accurate measurement time, and the threshold voltage of the first described voltage comparator is 0.9-1.0V.The threshold voltage of described second voltage comparer is the 92%-97% of testing capacitor rated insulation voltage value.Above-mentioned threshold voltage is set according to testing capacitor.
In this programme, constant-current charge method, the definition of root jade pendant capacitor, the electric weight Q of the capacity C of capacitor and its storage, and its current potential U, have into lower relation:
C=Q/U
Under normal conditions, capacitor is linear time invariant element, therefore to time diffusion:
C=dQ/dt/dU/dt
According to the definition of electric current: I=dQ/dt, above formula becomes:
C=I/?du/dt
=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})
Ideal capacitor is carried out to constant current and fill (putting) electricity, voltage and time on it are linear, as long as measure U1, U2, T1, T2 just can obtain the capacity C of testing capacitor, to double layer capacitor, leakage current is almost equal to zero, though there is internal resistance, but without impact, because calculate what use, be all changing value on test.Before survey formula, testing capacitor is fully discharged until its both end voltage is zero, recharge, with oscillograph recording charge switch, connect, until the voltage on testing capacitor is to threshold voltage, then the overall process of cut-off switch.
Measuring method according to described electric double layer super capacitor cubic content measurement circuit, wherein, comprises the following steps,
S1. by testing capacitor electric discharge, the voltage that makes testing capacitor two ends is 0;
S2. the charging current of setting constant current source is I, then the threshold voltage of setting respectively the first voltage comparator, second voltage comparer is V1, V2;
S3. by timer zero clearing;
S4. switch is closed, and the A end of switch connects constant current source, starts charging;
S5. when the voltage of testing capacitor reaches respectively threshold voltage V1, the V2 of the first voltage comparator and second voltage comparer, the corresponding time T 1 of timer record, T2;
S6. obtain data I, V1, V2, T1, the T2 of measuring process record, can be calculated testing capacitor capacity and be C=I* (T2-T1)/(V2-V1).
After described step S5, change testing capacitor, be loaded on another testing capacitor, then repeat step S3-step S5.After described step S5, measure completely, after deenergization, carry out again step S6.The output steady current of described constant current source is 0.01400 ± 0.00001A.
Compared with prior art, beneficial effect is: the A end connection constant current source of switch of the present invention is for testing capacitor is charged, and the B end of switch connects constant-current discharge circuit and is used for capacitor discharge to be measured.Its circuit connects simple, and cost is lower, widespread use on a large scale.Further, provide the measuring method of this circuit of application, its measuring method step is succinct.
Embodiment
Accompanying drawing, only for exemplary illustration, can not be interpreted as the restriction to this patent; For better explanation the present embodiment, some parts of accompanying drawing have omission, zoom in or out, and do not represent the size of actual product; To those skilled in the art, in accompanying drawing some known configurations and explanation thereof may to omit be understandable.
As shown in Figure 1, a kind of electric double layer super capacitor cubic content measurement circuit, wherein, comprise timer 1, the first voltage comparator 2, the second voltage comparer 3 that are connected with timer 1, also comprise constant current source 4, constant-current discharge circuit 5, switch 6, constant current source 4 is connected with the first voltage comparator 2, second voltage comparer 3 respectively, testing capacitor 7 one end ground connection, other end connecting valve 6, the A of switch 6 holds and connects constant current source 4 for testing capacitor 7 is charged, and the B end of switch 6 connects constant-current discharge circuit 5 for testing capacitor 7 is discharged.
In the present embodiment, the electric current syndeton of metering circuit is simple, and timer can 1 accurate measurement time, and the threshold voltage of the first described voltage comparator 2 is 0.9-1.0V.The threshold voltage of described second voltage comparer 3 is the 92%-97% of testing capacitor 7 rated insulation voltage values.Above-mentioned threshold voltage is set according to testing capacitor 7.
Measuring method according to described electric double layer super capacitor cubic content measurement circuit, wherein, comprises the following steps,
S1. by testing capacitor 7 electric discharges, the voltage that makes testing capacitor 7 two ends is 0;
S2. the charging current of setting constant current source 4 is I, then the threshold voltage of setting respectively the first voltage comparator 2, second voltage comparer 3 is V1, V2;
S3. by timer 1 zero clearing;
S4. switch 6 closures, the A end of switch 6 connects constant current source 4, starts charging;
S5. when the voltage of testing capacitor 7 reaches respectively threshold voltage V1, the V2 of the first voltage comparator 2 and second voltage comparer 3, timer 1 records corresponding time T 1, T2;
S6. obtain data I, V1, V2, T1, the T2 of measuring process record, can be calculated testing capacitor 7 capacity and be C=I* (T2-T1)/(V2-V1).
After described step S5, change testing capacitor 7, be loaded on another testing capacitor 7, then repeat step S3-step S5.After described step S5, measure completely, after deenergization, carry out again step S6.The output steady current of described constant current source is 0.01400 ± 0.00001A.
Concrete, to A sample, its charging process voltage is as follows over time:
The output steady current of constant current source 4 is 0.01400 ± 0.00001A.
Test for the first time: Δ U=2.74V, Δ t=60.00s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X60.00/2.74
=306.57?X10
^{-3}（F）
Test for the second time: Δ t=62.00s, Δ U=2.82V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X62.00/2.82
=307.80?X10
^{-3}?(F)
Test for the third time: Δ t=67.20s, Δ U=2.94V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X67.20/2.94
=320.00?X10
^{-3}?(F)
C mean value: (320.00+307.80+306.57)=311.46 X10
^{-3}(F)
A sample capacity: 320.00 ± 7.42X10
^{-3}(F)
To B sample, its charging process voltage is as follows over time:
Test for the first time: Δ t=68.40s, Δ U=2.82V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X68.40/2.82
=339.57?X10
^{-3}?(F)
Test for the second time: Δ U=2.80V, Δ t=64.40s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X64.40/2.80
=322.00?X10
^{-3}?(F)
Test for the third time: Δ U=3.04V, Δ t=69.00s
C==I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X69.00/3.04
=317.76?X10
^{-3}?(F)
C mean value: (317.76+322.00+339.57) X10
^{-3}=326.44X10
^{-3}(F)
B sample capacity: (326.44 ± 11.56) X10
^{-3}(F)
To C sample, its charging process voltage is as follows over time:
Test for the first time: Δ t=68.40s, Δ U=3.10V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X68.40/3.10
=308.90?X10
^{-3}?(F)
Test for the second time: Δ U=3.08V, Δ t=66.00s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X66.00/3.08
=300.00?X10
^{-3}?(F)
Test for the third time: Δ t=61.80s, Δ U=2.94V
C==I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X61.80/2.94
=294.29?X10
^{-3}?(F)
C mean value: (294.29+300.00+308.90)=301.11 X10
^{-3}(F)
C sample capacity: (301.11 ± 6.01) X10
^{-3}(F)
To D sample, its charging process voltage is as follows over time:
Test for the first time: Δ t=63.20s, Δ U=2.64V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X63.20/2.64
=335.15?X10
^{-3}?(F)
Test for the second time: Δ U=2.58V, Δ t=61.20s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X61.20/2.58
=332.15?X10
^{-3}?(F)
Test for the third time: Δ U=2.86V, Δ t=68.60s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X68.60/2.86
=335.80?X10
^{-3}?(F)
C mean value: (335.80+332.15+335.15)=334.37 X10
^{-3}(F)
D sample capacity: (334.37 ± 3.79) X10
^{-3}(F)
To E sample, its charging process voltage is as follows over time:
Test for the first time: Δ t=61.60s, Δ U=2.86V
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X61.60/2.86
=301.54?X10
^{-3}?(F)
Test for the second time: Δ U=2.90V, Δ t=62.00s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X62.00/2.90
=299.31?X10
^{-3}?(F)
Test for the third time: Δ U=2.96V, Δ t=63.20s
C=I/[(U
_{2}-U
_{1})/(t
_{2}?–t
_{1})=I/ΔU/Δt=IXΔt/ΔU
=14.00X10
^{-3}X63.20/2.96
=298.92?X10
^{-3}?(F)
C mean value: (298.92+299.31+301.54)=299.92 X10
^{-3}(F)
E sample capacity: (299.92 ± 1.35) X10
^{-3}(F)
To F sample
This sample cannot charge by the electric current of 14mA, therefore not test.
The corresponding same or analogous parts of same or analogous label; In accompanying drawing, describe position relationship only for exemplary illustration, can not be interpreted as the restriction to this patent.
The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can do the improvement of some applicable actual conditions to the technical scheme of invention.Therefore, protection scope of the present invention is not limited to this, and those of skill in the art are any to be included within protection domain of the present invention based on non-material change in technical solution of the present invention.