Electrical power steering apparatus

An electrical power steering apparatus including;

• a high voltage power source generating a high voltage of more than 100 volts;
• an electrical motor generating steering assist force presented to a steering mechanism of a vehicle;
• and
• a motor control circuit, said motor control circuit including:
• a motor drive circuit including a plurality of switching elements supplying drive current to said electrical motor;
• a power relay opening and closing a conduct between said high voltage power source and said motor drive circuit;
• a converter division supplying power to said motor drive circuit;
• and
• a smoothing condenser absorbing any current ripple;
• wherein
• said converter division including a step down circuit reducing said high voltage of said high voltage power source to a low voltage lower than said high voltage, a low voltage charge device charged through said step down circuit, and a switch equipped to shut and connect a conduct between said low voltage charge device and said motor drive circuit;
• and
• said motor drive circuit is connected with said low voltage charge device, and is disconnected from a direct connection with said high voltage power source, when a collision of said vehicle occurs, so that steering assistance is still possible but a risk of electric shock to occupants of said vehicle is prevented.