Electric car charger

Abstract

The invention discloses an electric vehicle charger. The charger comprises a positive pulse generation circuit, a negative pulse generation circuit, an isolation part, a charging tube and a discharging tube, wherein the positive pulse generation circuit and the negative pulse generation circuit both adopt the 555 time base integrated circuit which is connected on the utmost back end of low voltage output of a main power supply; an output end of the positive pulse generation circuit is connected with the charging tube by the isolation part, and an output end of the negative pulse generation circuit is connected with the discharging tube; and the charging tube and the discharging tube are both connected with the storage battery to be charged. The charger of the invention has the advantages that interferences on pulse waveforms and frequency signals, caused by the multistage conversion of circuit, are avoided; due to the adoption of optical coupling isolation between positive and negative square wave pulse signals and a last stage pulse current output tube, the wear of a current output tube caused by the switchoff of the main power supply is avoided when the square wave pulse is at low level, and the output of the power supply can be quickly and clearly switched off; therefore, in practice, the invention can effectively prolong service lives of the charger and the storage battery.

Description

【Technical field】 [0001] The invention relates to a charger for an electric vehicle storage battery, in particular to an electric vehicle charger with adjustable positive and negative square wave pulses. 【technical background】 [0002] During the use of electric vehicles, the battery needs to be charged repeatedly to provide power. When charging the battery, the positive pulse current can be used to quickly charge the battery; the negative pulse is used to discharge the battery briefly during the charging interval, which can eliminate polarization, increase the acceptance capacity of the plate, reduce the charging temperature, and prolong the service life of the battery. But to really achieve this effect, the following three conditions must be met: 1. Accurate square wave pulse and frequency; 2. Appropriate discharge interval time; 3. When discharging, the main power output must be turned off in time and completely. [0003] Although the chargers currently on the market als...

AI Technical Summary

Problems solved by technology

[0003] Although the chargers currently on the market also use positive pulse charging and short-term negative pulse discharge, the pulse waveform and frequency of this charger are designed at the front high voltage of the circuit, relying on a dedicated chip (PWM) circuit released The output pulse waveform and frequency, the signal is converted by the back-end multi-level circuit, and when it reaches the low-voltage output of the main power supply, the waveform is messy and the frequency is unstable

The positive and negative square wave pulse signals are directly connected to the final pulse current output tube. When the square wave pulse is at a low level and the main power is turned off, it will cause loss to the current output tube. At the same time, when the discharge negative pulse signal appears, The output of the power supply cannot be turned off quickly and cleanly, and the short-term discharge cannot be simply and powerfully

Therefore, the current charger cannot well meet the above three requirements. Its waveform is messy, the frequency is unstable, and the main power output cannot be completely turned off when discharging. It is not a negative pulse charger in the true sense and cannot achieve The effect of prolonging the service life of the battery

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