3 results about "Current generator" patented technology

The invention relates to a system and method for evaluating the voltage-sensitive characteristic of a lightning arrester valve plate under multiple lightning strokes, and belongs to the technical field of lightning arrester performance evaluation. A lightning arrester valve plate is arranged in a test box, and two metal electrodes are arranged on the upper portion and the lower portion of the valve plate; the output end of a multi-impulse current generator is connected to a first metal electrode, and a second metal electrode is connected with the grounding device; a temperature and humidity sensor is further arranged in the test box and can measure the temperature and humidity conditions of the test; a current sensor sleeves a current injection lead to measure the amplitude of the multi-impact current and the time when the waveform of the multi-impact current reaches the maximum value; two input ends of a high-voltage probe are respectively connected with the first metal electrode and the second metal electrode to measure the overvoltage amplitude of the lightning arrester valve plate; and in combination with the measured data, a voltage-sensitive characteristic evaluation factor of the lightning arrester valve plate is calculated, and the voltage-sensitive characteristic of the lightning arrester is evaluted. According to the invention, accurate control of multi-impulse current waveforms is realized, and the accuracy of voltage-sensitive characteristic evaluation of the lightning arrester valve plate under the action of multiple lightning strokes is improved.

An electronic device generates a current with a predetermined temperature coefficient. The circuit comprises a temperature coefficient (TC) component receiving a bias current, a differential amplifier providing a buffered output voltage based on the voltage across the TC component and a resistor receiving an TC current based on the differential amplifier output voltage. The differential amplifier has a predetermined input related offset which decreases the voltage drop across the resistor. The temperature coefficient component could have either a negative temperature component (NTC) or a positive temperature component (PTC).