CN111965713A - Passive constant voltage clamping transient electromagnetic transmitting circuit - Google Patents

Passive constant voltage clamping transient electromagnetic transmitting circuit Download PDF

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CN111965713A
CN111965713A CN202010679064.4A CN202010679064A CN111965713A CN 111965713 A CN111965713 A CN 111965713A CN 202010679064 A CN202010679064 A CN 202010679064A CN 111965713 A CN111965713 A CN 111965713A
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power supply
diode
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王广君
丁呈祥
王召辉
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China University of Geosciences
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China University of Geosciences
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Abstract

The invention provides a passive constant-voltage clamping transient electromagnetic transmitting circuit, which is characterized in that a resistor, a TVS device and a switching tube are connected in parallel and then connected into a main transmitting bridge circuit; in the early stage of the turn-off of the emission current, a TVS is used for forming a high-voltage clamp to realize the rapid turn-off of the emission current; in the later period of the reduction of the emission current, energy on a load inductor is discharged through a resistor, so that the overshoot and the oscillation of the emission current are prevented; according to the energy consumption principle of the resistor, the clamping principle of the TVS device and the switching characteristic of the switching tube, the characteristics and advantages of each device, the comprehensive efficiency and quality factors are organically combined, the detection blind area is reduced, and a foundation is laid for high precision; effectively solves the problems of long falling edge time and serious overshoot and oscillation of the transmitting current caused by parasitic inductance of the transmitting coil in the transient electromagnetic transmitter, and adjusts the clamping voltage and the resistor R of the TVS1The waveform is flexibly adjusted, so that the overshoot and the oscillation can be inhibited while the turn-off time of the emission current is reduced, and the waveform quality of the emission current is improved.

Description

Passive constant voltage clamping transient electromagnetic transmitting circuit
Technical Field
The invention relates to the technical field of transient electromagnetic emission, in particular to a transient electromagnetic emission circuit with a passive constant-voltage clamp.
Background
The Transient Electromagnetic Method (TEM) is a commonly used Electromagnetic detection Method, in which alternating pulse current is injected into a transmitting coil to generate a primary field signal, a receiving coil is used to receive a secondary field signal induced by an underground geologic body, and the basic information of the underground geologic body can be obtained by studying the received secondary field signal. The transient electromagnetic method is widely applied to the fields of mineral resource exploration and engineering detection.
The transient electromagnetic method requires that bipolar pulse current injected into a transmitting coil is instantly turned off without overshoot, but due to parasitic inductance of the transmitting coil, the transmitting current always needs a certain time to be turned off (turn-off time), and a certain overshoot and oscillation are always accompanied after the turn-off, so that the extraction of early signals is seriously influenced, and the shallow detection capability of the transient electromagnetic method is greatly limited. The research on a bipolar pulse current source which is rapidly turned off and has no overshoot is an important content in the current transient electromagnetic emission technology. Compared with the imported instruments, the transmission current waveform quality of the domestic developed transient electromagnetic transmitter has a large difference, which mainly shows that the transmission current is turned off for too long time and the transient electromagnetic transmitter is subjected to severe overshoot oscillation.
The active constant voltage clamp circuit proposed in the document "constant voltage clamp bipolar pulse current source of energy feed type" (Duming, Binzhong, cones, etc.. constant voltage clamp bipolar pulse current source of energy feed type [ J ]. the institute of Electrical and technology, 2008,22(8):57-62.) essentially clamps the load inductance to the new high voltage source during the falling edge of the emission current, and utilizes the idea of high voltage clamp to realize the fast turn-off of the emission current, but accompanied by relatively strong overshoot and oscillation, and the circuit must be connected with a blocking diode in series in the loop, and the circuit loss is very large and the efficiency is low at large current.
The method for suppressing overshoot oscillation proposed in the literature "generation principle and suppression of overshoot of transmission current for time domain electromagnetic detection" (Weeking, Tang hong faith, Guo Xin, etc.. the generation principle of overshoot of transmission current for time domain electromagnetic detection and suppression [ J ]. school newspaper of Jilin university (engineering edition), 2013,43(4): 180-. However, the junction capacitance of the IGBT is ignored during modeling, and the layout capacitance inevitably exists in the transmitting bridge circuit, so that theoretical calculation results and experimental results have larger access, and although certain guiding significance exists, larger errors exist.
Disclosure of Invention
In order to solve the problems, the invention provides a transient electromagnetic transmitting circuit with a passive constant voltage clamp, which is combined with the characteristics and the advantages of a passive constant voltage clamp rapid turn-off circuit, an active constant voltage clamp circuit, an idea of realizing rapid turn-off of transmitting current by using a high voltage clamp and an idea of utilizing an accelerating resistor to inhibit the transmitting current from overshooting an oscillating circuit, wherein the circuit not only can reduce the turn-off time of the transmitting current, but also can inhibit the overshooting and the oscillating of the transmitting current;
the passive constant-voltage-clamped transient electromagnetic transmitting circuit comprises: MOS tube Q1～Q4And a switching tube Q5～Q6Diode D1Diode D2Inductor L and resistor R1Resistance R2Resistance RLAnd a power supply VCC；
Wherein, MOS tube Q1～Q4A full bridge circuit constituting a transmitter; inductor L and resistor RLAfter being connected in series, the series-connected seriesL(ii) a Diode D1And a diode D2Are all transient suppression diodes TVS, resistors R for clamping1Resistance R2Respectively connected with a diode D1Diode D2After parallel connection, the main circuit is accessed;
MOS tube Q1～Q4And a switching tube Q5～Q6MOS tubes which are all N-channel; and Q1And Q6A parasitic diode is connected between the S pole and the D pole.
Further, MOS transistor Q1～Q4The specific circuit connection relationship of the full bridge circuit constituting the transmitter is as follows:
power supply VCCRespectively with the positive electrode of the MOS transistor Q1And MOS transistor Q2The D level is electrically connected; MOS tube Q1S pole and MOS tube Q2Are respectively electrically connected to the MOS transistor Q3D pole and MOS transistor Q4D stage of (1); MO (metal oxide semiconductor)S tube Q3S pole and MOS tube Q4S-level is electrically connected to a power supply VCCThe negative electrode of (1).
Further, a switch tube Q6S pole, resistance R1One terminal of (1), diode D1Is connected with an MOS tube Q2S stage and MOS transistor Q4The D-level connection of (1); switch tube Q6D pole, resistance R1Another terminal of (1), diode D1The cathode is connected with one end of the transmitting coil; switch tube Q5S pole, resistance R2One terminal of (1), diode D2Is connected with an MOS tube Q1S stage and MOS transistor Q3The D level is electrically connected; switch tube Q5D pole, resistance R2Another terminal of (1), diode D2The cathode of the transmitting coil is connected with the other end of the transmitting coil.
Further, the working process of the passive constant voltage clamped transient electromagnetic transmitting circuit sequentially comprises four beats: the power supply is stopped when the power supply is positive, and the power supply is stopped when the power supply is negative; the method specifically comprises the following steps:
forward power supply: in forward power supply, Q1、Q4、Q5、Q6All are opened, and a forward current flows in the load inductor, and the current flow direction is VCC→Q1→Q5→L→RL→Q6→Q4(ii) a The load inductor is an inductor L;
stopping power supply: end time of forward power supply, Q1、Q4、Q5、Q6At the same time, the load inductance generates reverse induced electromotive force to make D1Reverse conduction, load inductance passing through D1Discharge of energy from D1The voltage at two ends of the diode is limited at high voltage, and the emission current is rapidly reduced; when the current drops to D1Reverse conducting critical current IppWhen D is1When cut off, the inductor can only pass through the resistor R1Discharging, and the current is exponentially reduced; the high voltage is the clamping voltage of the selected transient suppression diode TVS;
reverse power supply: the reverse power supply process is similar to the forward power supply process;
stopping power supply: end of reverse power supply, Q2、Q3、Q5、Q6At the same time, the load inductance generates reverse induced electromotive force to make D2Reverse conduction is realized, and the load inductor L passes through D2Carrying out energy discharge; from D2Limiting the voltage at two ends of the TVS to the clamping voltage value of the TVS, and rapidly reducing the emission current; when the current drops to D2Reverse conducting critical current IppWhen D is2Off, the inductance passing only through the resistance R2And (4) discharging.
Further, at the end of the forward power supply, the discharging process of the inductor L includes the following three stages:
first stage t0≤t＜t1：t＝t0At that time, the forward power supply is cut off, and the load inductance generates an induced electromotive force, D1The voltage at the two ends begins to rise; t ═ t1Time of day, D1The voltage at both ends rises to D1Breakdown voltage of, D1Breakdown, limiting the voltage at a fixed value, and entering a second stage;
second stage t1≤t＜t2：t＝t1When D is1Reverse conduction, load inductance passing through D1Form a free-wheeling circuit, D1Clamping the voltage at two ends of the load inductor; t is t2When D is1Cutting off and entering a third stage;
t is more than or equal to t in the third stage2：t＝t2When D is2Cut-off, the load inductance passing through the resistor R1And (4) discharging.
Further, the current falling time t of the second stage1As shown in equation (1):
Figure BDA0002585191950000031
in the above formula, L is the inductance of the inductor L, RLIs a resistance RLResistance value of R1Is a resistance R1Resistance value of (1)0For emitting current, U1For transmitting voltage across the coil, U1＝VCC+3×AU+UD2Delta U is MOS tube parasitic diode conduction voltage drop, UD2Is the clamping voltage of TVS.
Further, the current falling time t of the third stage1As shown in equation (2):
Figure BDA0002585191950000032
in the above formula, U2＝VCC+3 × Δ U, Δ U is the conduction voltage drop of the parasitic diode of the MOS transistor.
Furthermore, the passive constant voltage clamped transient electromagnetic transmitting circuit transmits current turn-off time tdAs shown in equation (3):
Figure BDA0002585191950000041
the technical scheme provided by the invention has the beneficial effects that: the transient electromagnetic transmitting circuit with the passive constant-voltage clamp provided by the invention adjusts the resistor R1The value of (2) inhibits the overshoot and the oscillation of the emission current, can improve the quality of the emission current waveform in two aspects, is beneficial to the post data processing of the transient electromagnetic method, and reduces the detection blind area of the transient electromagnetic method.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a circuit diagram of a passive constant voltage clamped transient electromagnetic transmitter circuit in an embodiment of the present invention;
FIG. 2 is an equivalent circuit diagram of the second stage of load inductor discharging in the embodiment of the present invention;
FIG. 3 is an equivalent circuit diagram of a third stage load inductor discharge according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating theoretical values of turn-off time in an embodiment of the present invention;
FIG. 5 is a schematic diagram of a simulation of a passive constant voltage clamped transient electromagnetic transmitter circuit according to an embodiment of the present invention;
FIG. 6 is a diagram illustrating emission current waveforms at different clamping voltages according to an embodiment of the present invention;
FIG. 7 shows a graph of R in an embodiment of the present invention1A schematic diagram of a transmission current waveform under different resistance values.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
The embodiment of the invention provides a passive constant-voltage clamping transient electromagnetic transmitting circuit, which is mainly characterized in that a resistor, a TVS device and a switching tube are connected in parallel and then connected into a main transmitting bridge circuit; in the early stage of the turn-off of the emission current, a TVS is used for forming a high-voltage clamp to realize the rapid turn-off of the emission current; in the later period of the reduction of the emission current, energy on a load inductor is discharged through a resistor, so that the overshoot and the oscillation of the emission current are prevented; according to the energy consumption principle of the resistor, the clamping principle of the TVS device and the switching characteristic of the switching tube, the characteristics and advantages of each device, the comprehensive efficiency and quality factors are organically combined, the detection blind area is reduced, and a foundation is laid for high precision; the two combined actions effectively solve the problems of long falling edge time and serious overshoot and oscillation of the transmitting current caused by parasitic inductance of the transmitting coil in the transient electromagnetic transmitter, and can adjust the clamping voltage and the resistor R of the TVS1The waveform is flexibly adjusted, so that the overshoot and the oscillation can be inhibited while the turn-off time of the emission current is reduced, and the waveform quality of the emission current is improved.
Referring to fig. 1, fig. 1 is a circuit diagram of a passive constant voltage clamped transient electromagnetic transmitting circuit according to an embodiment of the present invention; the method comprises the following steps: MOS tube Q1～Q4And a switching tube Q5～Q6Diode D1Diode D2Inductor L and resistor R1Resistance R2Resistance RLAnd a power supply VCC(ii) a The specific parameter size of each component can be set according to actual requirements;
wherein, MOS tube Q1～Q4A full bridge circuit constituting a transmitter; inductor L and resistor RLAfter being connected in series as emissionThe parasitic inductance and the parasitic resistance of the parasitic parameters of the coil and the transmitting coil are respectively inductance L and resistance RL(ii) a Diode D1And a diode D2Are all transient suppression diodes TVS, resistors R for clamping1Resistance R2Respectively connected with a diode D1Diode D2After parallel connection, the main circuit is accessed;
MOS tube Q1～Q4And a switching tube Q5～Q6MOS tubes which are all N-channel; and Q1And Q6A parasitic diode is connected between the S pole and the D pole.
Wherein, MOS tube Q1～Q4The specific circuit connection relationship of the full bridge circuit constituting the transmitter is as follows:
power supply VCCRespectively with the positive electrode of the MOS transistor Q1And MOS transistor Q2The D level is electrically connected; MOS tube Q1S pole and MOS tube Q2Are respectively electrically connected to the MOS transistor Q3D pole and MOS transistor Q4D stage of (1); MOS tube Q3S pole and MOS tube Q4S-level is electrically connected to a power supply VCCThe negative electrode of (1).
Switch tube Q6S pole, resistance R1One terminal of (1), diode D1Is connected with an MOS tube Q2S stage and MOS transistor Q4The D-level connection of (1); switch tube Q6D pole, resistance R1Another terminal of (1), diode D1The cathode is connected with one end of the transmitting coil; switch tube Q5S pole, resistance R2One terminal of (1), diode D2Is connected with an MOS tube Q1S stage and MOS transistor Q3The D level is electrically connected; switch tube Q5D pole, resistance R2Another terminal of (1), diode D2The cathode of the transmitting coil is connected with the other end of the transmitting coil.
The working process of the whole circuit comprises four beats in sequence: the power supply is stopped when the power supply is positive, and the power supply is stopped when the power supply is negative;
forward power supply: in forward power supply, Q1、Q4、Q5、Q6All are switched on, and forward current and electricity flow in the load inductorThe flow direction is VCC→Q1→Q5→L→RL→Q6→Q4(ii) a Because the on-resistance of the switching tube is extremely small after the switching tube is conducted, R1、R2Is equivalent to Q5、Q6Short-circuiting, and no extra loss is brought to a transmitting system (a transient electromagnetic instrument transmitter or a transient electromagnetic instrument transmitting system); the load inductor is an inductor L;
stopping power supply: end time of forward power supply, Q1、Q4、Q5、Q6At the same time, the load inductor (inductor L) generates reverse induced electromotive force to make D1(transient suppressor TVS) is turned on in reverse, and the load inductance (parasitic inductance of the transmitter coil) passes through D1Discharge of energy from D1The voltage at two ends of the load inductor is limited at high voltage, so that the emission current is rapidly reduced; when the current drops to a certain degree (to TVS reverse conduction critical current I)pp) Then, TVS is cut off, and the inductor can only pass through the resistor R1Discharging, wherein the current is exponentially reduced, so that overshoot and oscillation can be effectively avoided; the high voltage is a technical parameter of the transient suppression diode TVS, namely clamping voltage;
reverse power supply: the reverse power supply process is similar to the forward power supply process;
stopping power supply: end of reverse power supply, Q2、Q3、Q5、Q6At the same time, the load inductance generates reverse induced electromotive force to make D2(transient suppression diode TVS) reverse conduction, load inductance L passes through D2Carrying out energy discharge; from D2The voltage at the two ends of the TVS can be limited to the clamping voltage value of the TVS, so that the emission current can be rapidly reduced; when the current drops to TVS reverse conduction critical current IPPWhen the TVS is cut off, the inductor can only pass through the resistor R2And (4) discharging.
At the end of the forward supply, Q1、Q4、Q5、Q6Simultaneously cutting off; at the end of the reverse supply, Q2、Q3、Q5、Q6Simultaneously cutting off; MOS tube and transient suppression diode TV participating in discharging process under two conditionsS and resistance are different, but the three stages of the discharging process of the inductor and the specific derivation process and related parameters are completely the same. The following analysis of the discharge process of the inductor with the end of the positive supply therefore has three phases:
(1) first stage (t)0≤t＜t1)，t＝t0When the forward power supply is cut off, the load inductance generates an induced electromotive force, TVS (D)1) The voltage at the two ends begins to rise; t is t1Time of day, TVS (D)1) The voltage at both ends rises to TVS (D)1) Breakdown voltage of, TVS (D)1) Breakdown, limiting the voltage at a fixed value, and entering a second stage; the essence of the first stage is the process that the load inductance charges the TVS parasitic junction capacitance;
(2) second stage (t)1≤t＜t2)，t＝t1Then, TVS (D)1) Reverse conduction, load inductance through TVS (D)1) Form a free-wheeling circuit, TVS (D)1) Clamping the voltage at two ends of the load inductor; t is t2Then, TVS (D)1) Cutting off and entering a third stage; in the second stage, the load inductor mainly passes through TVS (D)1) Discharging; the equivalent circuit of the load inductor discharge loop is shown in fig. 2:
this stage is due to TVS (D)1) Clamping the voltage, so it can be equivalent to a voltage source D1The linear differential equation of the inductance L obtained from kirchhoff's law is shown in formula (1):
Figure BDA0002585191950000061
in the above formula, i is the current, t is the time, U1To transmit the voltage across the coil;
solving the differential equation to obtain formula (2):
Figure BDA0002585191950000071
in the above formula, I0Is an emission current;
order to
Figure BDA0002585191950000072
The second-stage current drop time can be obtained as shown in formula (3):
Figure BDA0002585191950000073
in the above formula, U1＝VCC+3 × AU + UD2, AU is MOS tube parasitic diode conduction voltage drop, UD2The clamping voltage of TVS is usually several hundred volts, which is much larger than the power supply voltage, so U1May be equivalent to the clamping voltage of a TVS;
(3) the third stage (t is more than or equal to t)2)，t＝t2Then, TVS (D)2) Cut-off, the load inductance passing through the resistor R1Discharging, the equivalent circuit of the load inductor discharging loop is shown in fig. 3;
the linear differential equation of the inductance obtained according to kirchhoff's law is shown in formula (4):
Figure BDA0002585191950000074
solving the differential equation to obtain formula (5):
Figure BDA0002585191950000075
in the above formula, I1The magnitude of the current at the moment of entering the third stage, namely:
Figure BDA0002585191950000076
when i (t) is equal to 0, the third-stage current drop time is obtained as shown in formula (6):
Figure BDA0002585191950000077
in the above formula, U2＝VCC+3 × Δ U, Δ U being parasitic two of MOS transistorThe voltage drop across the diode, U, is much greater than the voltage drop across the diode2And may be equivalent to a supply voltage.
Off-time t of emission currentdEqual to the sum of the durations of the three phases, wherein the duration of the first phase depends on the magnitude of the emission current and TVS (D)1) Due to TVS (D)1) The parasitic junction capacitance is very small, and the duration of the first stage is negligible relative to the time of the whole emission current drop; so that the circuit emits a current for a turn-off time tdAs shown in equation (7):
Figure BDA0002585191950000081
the following description of simulation examples of the passive constant voltage clamp fast turn-off circuit and the active constant voltage clamp turn-off circuit:
(1) simulation analysis of passive constant-voltage clamp rapid turn-off circuit and active constant-voltage clamp turn-off circuit
From the equation (7), it can be seen that the clamping voltage U of TVS is changed1And a resistor R1Can change the off-time of the emission current. The clamping voltage of TVS determines the descending speed, U, of the emission current in the early stage1The larger the emission current, the faster the emission current decreases earlier. Resistance R1Determines the duration of stage three and also determines the waveform of the emission current at the later stage, R1The larger, the longer phase three lasts, the longer the off-time, but the better the ability to suppress overshoot and ringing. Therefore, the reduction of the turn-off time is achieved at the expense of the voltage withstanding value of the MOS tube, and the suppression of the overshoot and oscillation of the emission current is achieved at the expense of the turn-off time of a part.
Taking the coil parameter L as 1.5mH, R L1 Ω at emission current I0Under the condition of 10A, making the resistor R1Under different values, the turn-off time of the emission current is along with the clamping voltage U1The curve of the change. Off time t of active constant voltage clamp circuitd1As shown in equation (8):
Figure BDA0002585191950000082
in the above formula, L, RLRepresents a parasitic parameter of the transmit coil, U is the clamp voltage; for comparison with the active clamp circuit, the same parameters were chosen and the theoretical off-times for both circuits were made, the results are shown in fig. 4.
As can be seen from fig. 4, the off time of the circuit proposed by the present invention can greatly reduce the off time of the emission current as the clamp voltage increases, as with the active constant voltage clamp circuit. The circuit turn-off time provided by the invention is also equal to R1Is related to the value of R1The larger the value is, the smaller the turn-off time is, the closer to the turn-off time of the active constant voltage clamping circuit is, but R1Too large a value is not good for suppressing the overshoot and oscillation of the emission current. As can be seen from FIG. 4, when R is1When the value of the voltage is 1K omega, the turn-off time of the circuit provided by the invention is equivalent to that of an active constant voltage clamping circuit, and in addition, a blocking diode is not used in the circuit provided by the invention, so that the loss of a system is reduced, and the circuit has the advantage of inhibiting the overshoot oscillation of the emission current.
(2) Simulation and experimental verification of clamping voltage of passive constant-voltage clamping quick turn-off circuit
The circuit provided by the invention is simulated by adopting simulation software, and the circuit parameters are selected as follows: l1.5 mH, RL＝1Ω，I0The simulation results are shown in fig. 5, 10A:
it can be seen from fig. 5 that as the clamping voltage of the TVS increases, the turn-off time of the emission current becomes shorter and shorter without significant overshoot and oscillation, and the simulation result is consistent with the theoretical calculation.
The rapid turn-off circuit provided by the invention is tested and verified by simulating a transmitting coil by using a power resistor and a power inductor: the test parameters are selected from L ═ 1.5mH, RL＝1Ω，I010A; an Agilent oscilloscope (DSO7052B 500MHz 4GSa/s) is used for observing the emission current waveform on a linear Hall current sensor (HBC-ES5) in the test process. The clamp voltages in the experiment were taken:the test results are shown in FIG. 6 in four cases of 0V, 100V, 200V and 500V:
as can be seen from fig. 6, as the clamping voltage of the TVS increases, the turn-off time of the emission current gradually decreases from 0.8ms (without the clamping voltage) to about 30us (when the clamping voltage is 500V), which is shortened to less than one twentieth of the original time, and the experimental result is consistent with the theoretical calculation and simulation result.
To compare the resistance R1The effect on the emission current, the resistance R, under otherwise identical conditions1Four conditions of 10K omega, 1K omega, 510 omega and 330 omega are respectively taken for comparative experiments. The experimental results are shown in fig. 7; in fig. 7, the horizontal axis: time 20 uS/grid vertical axis: the current was 0.2A/cell.
As can be seen from FIG. 7, under otherwise identical conditions, when the resistance R is equal1When the value is large, the overshoot amplitude of the emission current is up to 0.3A, the oscillation time exceeds 100us, and along with the resistance R1The overshoot and the oscillation in the later period of the emission current are effectively inhibited.
The invention has the beneficial effects that: the transient electromagnetic transmitting circuit with the passive constant-voltage clamp provided by the invention adjusts the resistor R1The value of (2) inhibits the overshoot and the oscillation of the emission current, can improve the quality of the emission current waveform in two aspects, is beneficial to the post data processing of the transient electromagnetic method, and reduces the detection blind area of the transient electromagnetic method.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (8)

1. A passive constant voltage clamped transient electromagnetic transmit circuit, characterized by: the method comprises the following steps: MOS tube Q1～Q4And a switching tube Q5～Q6Diode D1Diode D2Inductor L and resistor R1Resistance R2Resistance RLAnd a power supply VCC；
Wherein, the MOS tubeQ1～Q4A full bridge circuit constituting a transmitter; inductor L and resistor RLAfter being connected in series, the series-connected seriesL(ii) a Diode D1And a diode D2Are all transient suppression diodes TVS, resistors R for clamping1Resistance R2Respectively connected with a diode D1Diode D2After parallel connection, the main circuit is accessed;
MOS tube Q1～Q4And a switching tube Q5～Q6MOS tubes which are all N-channel; and Q1And Q6A parasitic diode is connected between the S pole and the D pole.
2. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 1, wherein: MOS tube Q1～Q4The specific circuit connection relationship of the full bridge circuit constituting the transmitter is as follows:
power supply VCCRespectively with the positive electrode of the MOS transistor Q1And MOS transistor Q2The D level is electrically connected; MOS tube Q1S pole and MOS tube Q2Are respectively electrically connected to the MOS transistor Q3D pole and MOS transistor Q4D stage of (1); MOS tube Q3S pole and MOS tube Q4S-level is electrically connected to a power supply VCCThe negative electrode of (1).
3. The passive constant voltage-clamped transient electromagnetic transmitter circuit of claim 2, wherein: switch tube Q6S pole, resistance R1One terminal of (1), diode D1Is connected with an MOS tube Q2S stage and MOS transistor Q4The D-level connection of (1); switch tube Q6D pole, resistance R1Another terminal of (1), diode D1The cathode is connected with one end of the transmitting coil; switch tube Q5S pole, resistance R2One terminal of (1), diode D2Is connected with an MOS tube Q1S stage and MOS transistor Q3The D level is electrically connected; switch tube Q5D pole, resistance R2The other end of the first end of the second end of the first,Diode D2The cathode of the transmitting coil is connected with the other end of the transmitting coil.
4. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 1, wherein: the working process of the passive constant-voltage clamped transient electromagnetic transmitting circuit sequentially comprises four beats: the power supply is stopped when the power supply is positive, and the power supply is stopped when the power supply is negative; the method specifically comprises the following steps:
forward power supply: in forward power supply, Q1、Q4、Q5、Q6All are opened, and a forward current flows in the load inductor, and the current flow direction is VCC→Q1→Q5→L→RL→Q6→Q4(ii) a The load inductor is an inductor L;
stopping power supply: end time of forward power supply, Q1、Q4、Q5、Q6At the same time, the load inductance generates reverse induced electromotive force to make D1Reverse conduction, load inductance passing through D1Discharge of energy from D1The voltage at two ends of the diode is limited at high voltage, and the emission current is rapidly reduced; when the current drops to D1Reverse conducting critical current IppWhen D is1When cut off, the inductor can only pass through the resistor R1Discharging, and the current is exponentially reduced; the high voltage is the clamping voltage of the selected transient suppression diode TVS;
reverse power supply: the reverse power supply process is similar to the forward power supply process;
stopping power supply: end of reverse power supply, Q2、Q3、Q5、Q6At the same time, the load inductance generates reverse induced electromotive force to make D2Reverse conduction is realized, and the load inductor L passes through D2Carrying out energy discharge; from D2Limiting the voltage at two ends of the TVS to the clamping voltage value of the TVS, and rapidly reducing the emission current; when the current drops to D2Reverse conducting critical current IppWhen D is2Off, the inductance passing only through the resistance R2And (4) discharging.
5. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 4, wherein: at the end of the forward power supply, the discharge process of the inductor L includes the following three phases:
first stage t0≤t<t1：t＝t0At that time, the forward power supply is cut off, and the load inductance generates an induced electromotive force, D1The voltage at the two ends begins to rise; t is t1Time of day, D1The voltage at both ends rises to D1Breakdown voltage of, D1Breakdown, limiting the voltage at a fixed value, and entering a second stage;
second stage t1≤t<t2：t＝t1When D is1Reverse conduction, load inductance passing through D1Form a free-wheeling circuit, D1Clamping the voltage at two ends of the load inductor; t is t2When D is1Cutting off and entering a third stage;
t is more than or equal to t in the third stage2：t＝t2When D is2Cut-off, the load inductance passing through the resistor R1And (4) discharging.
6. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 5, wherein: current falling time t of the second stage1As shown in equation (1):
Figure FDA0002585191940000021
in the above formula, L is the inductance of the inductor L, RLIs a resistance RLResistance value of R1Is a resistance R1Resistance value of (1)0For emitting current, U1For transmitting voltage across the coil, U1＝VCC+3×ΔU+UD2Delta U is MOS tube parasitic diode conduction voltage drop, UD2Is the clamping voltage of TVS.
7. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 6, wherein: third-stage current drop time t1As shown in equation (2):
Figure FDA0002585191940000022
in the above formula, U2＝VCC+3 × Δ U, Δ U is the conduction voltage drop of the parasitic diode of the MOS transistor.
8. The passive constant voltage-clamped transient electromagnetic transmit circuit of claim 7, wherein: the passive constant-voltage clamping transient electromagnetic transmitting circuit emitting current turn-off time tdAs shown in equation (3):
Figure FDA0002585191940000031
CN202010679064.4A 2020-07-15 2020-07-15 Passive constant voltage clamping transient electromagnetic transmitting circuit Pending CN111965713A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113866835A (en) * 2021-11-10 2021-12-31 吉林大学 Electromagnetic emission system with time domain three-waveform combination and control method
CN115219764A (en) * 2022-07-11 2022-10-21 上海钧嵌传感技术有限公司 Pulse current protection circuit and method for current sensor and current sensor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002258709A (en) * 2001-03-05 2002-09-11 Fuji Xerox Co Ltd Cleaning device and image forming device using it
CN203455487U (en) * 2013-09-28 2014-02-26 吉林大学 FPGA-based multifunctional electrical transmitter
CN105119588A (en) * 2015-09-14 2015-12-02 吉林大学 Pulse current transmission circuit adopting transient electromagnetic method
CN105743385A (en) * 2016-04-26 2016-07-06 吉林大学 Current waveform shaping circuit for transient electromagnetic transmitter
CN107017610A (en) * 2017-05-11 2017-08-04 中国地质大学（武汉） A kind of passive constant pressure clamper of Transient Electromagnetic Transmitter rapidly switches off circuit
CN107783196A (en) * 2017-11-22 2018-03-09 中国地质大学（武汉） A kind of Transient Electromagnetic Apparatus emitter

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002258709A (en) * 2001-03-05 2002-09-11 Fuji Xerox Co Ltd Cleaning device and image forming device using it
CN203455487U (en) * 2013-09-28 2014-02-26 吉林大学 FPGA-based multifunctional electrical transmitter
CN105119588A (en) * 2015-09-14 2015-12-02 吉林大学 Pulse current transmission circuit adopting transient electromagnetic method
CN105743385A (en) * 2016-04-26 2016-07-06 吉林大学 Current waveform shaping circuit for transient electromagnetic transmitter
CN107017610A (en) * 2017-05-11 2017-08-04 中国地质大学（武汉） A kind of passive constant pressure clamper of Transient Electromagnetic Transmitter rapidly switches off circuit
CN107783196A (en) * 2017-11-22 2018-03-09 中国地质大学（武汉） A kind of Transient Electromagnetic Apparatus emitter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113866835A (en) * 2021-11-10 2021-12-31 吉林大学 Electromagnetic emission system with time domain three-waveform combination and control method
CN115219764A (en) * 2022-07-11 2022-10-21 上海钧嵌传感技术有限公司 Pulse current protection circuit and method for current sensor and current sensor

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