Transient electromagnetic transmitter circuit with load in parallel connection for discharging

Abstract

The invention relates to a transient electromagnetic transmitter circuit with loads in parallel connection for discharging. The transient electromagnetic transmitter circuit comprises a DC power supply, an H bridge circuit, load coils, bidirectional switches, a load discharging loop and a constant-voltage clamping circuit, wherein the DC power supply is connected with the load coil N through the H bridge circuit, the load coil I, the bidirectional switch I, the load coil II, the bidirectional switch II...; the load coil I, the load coil II,...and the load coil N are each connected with the load discharging loop; and the load discharging loop is connected with the DC power supply through the constant-voltage clamping circuit. Compared with the prior art, by adopting the bidirectional switches and diodes, the load coils are in a series connection state when the current rises and is stable, and the load coils are in parallel connection state in discharging. The transient electromagnetic transmitter circuit effectively reduces equivalent inductance of the loads in discharging, reduces turn-off delay time of the transmitter, and reduces transient electromagnetic detection blind zone. The load coil segmentation method is flexible, and parallel load inductance value can be changed according to specific detection requirements. Under the condition of same turn-off delay time, the transmitting current or load coil number can be increased, the equivalent magnetic moment is enlarged, and the detection depth and resolution are increased.

Description

technical field [0001] The invention relates to a transient electromagnetic detector circuit in geophysical exploration, in particular to a transient electromagnetic transmitter circuit applicable to various power levels. Background technique [0002] Transient electromagnetic detection instruments are widely used in the field of geophysical detection, and usually consist of a transmitter and a receiver. The detection depth and detection accuracy are not only related to the sampling speed, dynamic range, noise performance of the receiver, but also to the transmitter It is related to factors such as emission current, turn-off time, and turn-off waveform. The working principle is as follows, the inductive load formed by the transmitter to the multi-turn wire (as attached figure 2 shown) to send a bipolar current waveform (as attached image 3 As shown), the primary pulse magnetic field is excited, and the primary field propagates underground and excites the underground condu...

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Problems solved by technology

In addition, when detecting geological information at a deeper level (below 1km), it is necessary to generate a larger magnetic moment, which can be achieved by increasing the emission current or increasing the number of turns of the coil, but increasing the current or increasing the number of turns will bring The problem of increased transmitter turn-off delay and increased overshoot

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