This paper expounds the principle of lead-acid battery intelligent charging system, design the main circuit of the intelligent charging system, the positive and negative pulse charging circuit, control circuit and software design of intelligent charging system. Experimental results show that the system USES intelligent charging method can effectively improve the charging efficiency of battery and prolong the service life of the battery, can be widely used in lead-acid battery charging system, which has a broad prospect of industrialization and social benefits.

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In near space optical communication, the laser beam energy affects communication link distance directly, also laser beam quality affects the laser energy density, modulation efficiency, bit error rate (BER) of communication and other parameters. In this paper we have presented an experiment system of space optical communication, of which the transmitting power is 1w, modulation rate is 500 Mbps and link distance is 8 to 10 kilometers. Then the effects of optical fiber collimator, electro-optic modulator, optical antenna and other units on beam power loss, beam diameter, divergence angle and other parameters are analyzed. Last we put forward the way of increasing the laser transmitting distance and the optimization measure of system key unit.

A laser modulation and amplification system is designed to meet the demand of long-range space optical communication, which uses the high-speed semiconductor laser to integrate electro-absorption (EA) modulator as a seed source. Two optical fiber amplifier technologies are used. The erbium-doped fiber amplifier (EDFA) and single-mode semiconductor laser pumping are used in the first-level; erbium ytterbium co-doped fiber amplifier (EYDFA) and 2-4 multimode fiber laser pumping with good temperature characteristics are used in the second level, and the control method is automatic gain control. The experimental result shows that the modulation rate achieves to 10Gbps, and the output optical power achieves to 5W.

The visible light communication (VLC) technology based on the lighting system of space station is put forward. The VLC has advantages of not taking up radio spectrum, no electromagnet interference and radiation, high emission power and good secrecy. This paper mainly studies to improve inter-symbol interference and fading problem caused by multipath effects in VLC system using RAKE receiving technology. The simulation results in this paper indicate that optical receiving technology utilizing RAKE can not only resolve the inter-symbol interference and reduce the bit error rate (BER), but also improve the signal to noise ratio of the system output.