Week 10

1. Because a relay is a mechanical switch, it can be somewhat slow. 

2. A transistor is an electronic device that can work as a switch, and faster than relay.

3. Motor Characteristics:

• Voltage. Plan on the motor’s top speed being at rated voltage, and slowest speed at no more than 50% less than the rated voltage.​

• Current. Motors draw current depending on the load they’re pulling. Usually more load means more current. Every motor has a stall current, which is the current it draws when it’s stopped by an opposing force. This stall current is much greater than the running current, or current that it draws under no load. Your power supply for a motor should be able to handle the stall current with extra amperage to spare. Motors may draw near the stall current for a brief period of time when starting up, to overcome their inertia.

• Speed. Motor speed is given in revolutions per minute (RPMs).

• Torque is the measure of a motor’s pulling force. It’s measured by the force a motor can pull when the opposing force is attached to a shaft attached to its center rod. If the shaft sticks out a foot from the motor’s center, and the motor can pull one pound on that shaft, the motor’s torque is one foot-pound.

     4.motor driver,see week 4 

     5.H-bridge