In this thesis,the charge ordering(CO), magnetic-electronic correlation of the perovskite manganites, and electron paramagnetic resonance spectrum(EPR), following are the main results: Cr-doping system with peroviskite structure have been synthesized by solid-state reaction method.

The conglutination of electromagnetic switch is analyzed systematically according to the structure of fixed contact, material, return spring of movable contact and conduction ways.

The technology of flexible electrical switches is to use the high frequency power electronics switches in connection with the electromagnetic switch, associated with the shield method to gain ideal complementary effects.

This paper analyses the starter electromagnetic switch with power continuous on according to the structure of fixed contact,material,movable contact return spring,conduction ways and points out the return spring and conduction ways are the major factors influencing the power on of electromagnetic switch.

To solve starter overrunning clutch gear-milling,the author introduces a starter whose solenoid switch owns two separated terminals:pull-in terminal and holding terminal;the pull-in winding is made of iron wire.

This paper introduces several proprietary technologies of starter solenoid switch with current-limiting resistance developed by Denso, Valeo, Bosch and the author.

This paper introduces many means and circuits of no-load test, overall braking test and solenoid switch test.