Emission current subdivision control circuit based on magnetic source electromagnetic method

Abstract

The invention relates to an emission current subdivision control circuit based on a magnetic source electromagnetic method. The emission current subdivision control circuit based on a magnetic source electromagnetic method adopts a four-division accurate control mode, and is formed in a way that a primary power supply is connected with loading coils and is connected in parallel with a reverse overshooting control circuit through an H bridge inversion main circuit for outputting flat-top current, and after passing through an auxiliary power supply, the positive end of the primary power supply is respectively connected in parallel with a rising edge control circuit and a falling edge control circuit on the H bridge inversion main circuit. Compared with the prior art, the invention adopts the output current subdivision control, solves the conflict of mutual restriction between the flat-top section control and the rising edge and falling edge control mode, reduces the ripples and the electromagnetic interference of the flat-top current, decreases the turn-off time of the output current, and reduces the effect of the primary field in the shallow detection result interpretation of a large-magnetic moment transient electromagnetic device. Simultaneously, the invention reduces the switching number of the power device, reduces the switching loss of the power device, simplifies the control circuit, saves the cost and improves the efficiency.

Description

technical field [0001] The invention relates to a control circuit for transmitting current waveforms of an electromagnetic detection instrument, in particular to a segmented control circuit for a multi-turn coil transmitting device of a magnetic source. Background technique [0002] Magnetic source electromagnetic method instruments usually use H bridge circuit as the power conversion main circuit of the transmitting device, and the load is inductive. In order to reduce the power loss of the load resistance, a coil load with large inductance and small resistance is usually used, especially in the aviation electromagnetic method and downhole electromagnetic method. The size of the coil is limited in special occasions such as the law, and in fact most of them use small coils with multiple turns. Therefore, special requirements are put forward for the power conversion circuit of the magnetic source electromagnetic method transmitter. [0003] Since the resistance of the load c...

AI Technical Summary

Problems solved by technology

However, this control technology increases the intensity of electromagnetic interference generated by the power conversion circuit, and increases the switching loss of the bridge switching device; the received signal contains the fundamental frequency and harmonic interference of the PWM control signal, which is helpful for suppressing noise and improving The signal-to-noise ratio and the realization of on-time sampling have adverse effects; moreover, since the existing circuits use bridge switching devices in parallel with reverse diodes as the freewheeling path, the falling edge control power supply and the power supply are the same power supply, The voltage is too small, so that the shutdown current tails seriously and the shutdown time is long

[0004] The emission current of the magnetic source electromagnetic method includes two polarities of positive output and negative output. Conventional circuits have inherent defects. The rise and fall of the output current are too slow to achieve the required frequency and large current emission; Large overshoot affects receiver data acquisition

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