Passive constant-voltage clamped transient electromagnetic transmitting circuit

Abstract

The invention provides a passive constant-voltage clamped transient electromagnetic transmitting circuit. A resistor, a TVS device and a switching tube are connected in parallel and then are connectedto a main transmitting bridge circuit; in the early stage of turn-off of the transmitting current, a high-voltage clamp is formed by using the TVS to realize rapid turn-off of the transmitting current; in the later period of transmitting current reduction, energy on a load inductor is discharged through a resistor, and overshoot and oscillation of transmitting current are prevented; according tothe energy consumption principle of a resistor, the clamping principle of a TVS device and the switching characteristic of a switching tube, the characteristics and advantages of each device are organically combined, the efficiency and quality factors are integrated, the detection blind area is reduced, and a foundation is laid for high precision; the problems that in a transient electromagnetic transmitter, due to the fact that a transmitting coil has parasitic inductance, the falling edge time of transmitting current is long, and overshoot and oscillation are serious are effectively solved.The waveform is flexibly adjusted by adjusting the clamping voltage of the TVS and the resistor R1, overshoot and oscillation can be suppressed while the turn-off time of the transmitting current is shortened, and the waveform quality of the transmitting current is improved.

Description

technical field [0001] The invention relates to the technical field of transient electromagnetic emission, in particular to a transient electromagnetic emission circuit for passive constant voltage clamping. Background technique [0002] Transient electromagnetic method (TEM: Transient Electromagnetic Method) is a commonly used electromagnetic detection method at present. It injects alternating pulse current into the transmitting coil to generate a primary field signal, and then uses the receiving coil to receive the secondary field induced by the underground geological body. Finally, by studying the received secondary field signals, the basic information of underground geological bodies can be obtained. Transient electromagnetic method has been widely used in the field of mineral resource exploration and engineering detection. [0003] The transient electromagnetic method requires that the bipolar pulse current injected into the transmitting coil be turned off instantaneou...

AI Technical Summary

Problems solved by technology

However, due to the neglect of the IGBT junction capacitance and the layout capacitance in the emission bridge, the theoretical calculation results and experimental results have a large discrepancy. Although there is a certain guiding significance, there is a large error

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