MOTOR DRIVE CIRCUIT FOR LORRY

• Main Authors: KATO SONOO, ADACHI YOSHITAKA, YAMAMOTO JIRO, SAKAI TADASHI
• Format: Patent
• Language: English
• Published: 18.03.2004
• Edition: 7
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC EQUIPMENT OR PROPULSION OF ELECTRICALLY-PROPELLEDVEHICLES; ELECTRICITY; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES, IN GENERAL; GENERATION; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; PERFORMING OPERATIONS; TRANSPORTING; VEHICLES IN GENERAL

PROBLEM TO BE SOLVED: To surely brake a motor with at emergency times. SOLUTION: If an emergency switch SW3 is turned off (opened), a relay X6 is brought into non-excited state, which opens a normally open contact X6a and closes a normally closed contact X6b. Thus, a motor M is disconnected from a power line 27 which controls forward movement and backward movement. At the same time, only a closed circuit for braking by a short-circuit line 28 is formed. As a result of the formation of the closed circuit, a current is passed so that power generated by the motor M is consumed by a resistor R, and the brakes are drastically applied suddenly by electromagnetic induction. When the closed circuit for braking is formed, the normally open contact X6a is opened, and the power line 27 is disconnected. Therefore, even if normally open contacts X1a and X2a or X3a and X4a for forward/backward movement control are left closed due to faults, contact welding, or the like, power is not supplied from a power supply 25 to the motor M. Therefore, the brakes being surely applied, and excessive voltage being applied to the resistor R are avoided. COPYRIGHT: (C)2004,JPO