Body Computer: Summary

Body Computer

  • A computer is an electronic device that stores and processes data and is capable of operating other devices.
  • The operation of the computer is divided into four basic functions: input, processing, storage, and output.
  • Binary numbers are represented by the numbers 1 and 0. A transistor that operates as a relay is the basis of the digital computer. As the input signal switches from off to on, the transistor output switches from cutoff to saturation. The on and off output signals represent the binary digits 1 and 0.
  • Logic gates are the thousands of field effect transistors that are incorporated into the computer circuitry. The FETs use the incoming voltage patterns to determine the pattern of pulses that leave the gate. The most common logic gates are NOT, AND, OR, NAND, NOR, and XOR gates.
  • There are several types of memory chips used in the body computer; ROM, RAM, and PROM are the most common types.
  • ROM (read only memory) contains a fixed pattern of Is and O’s representing permanent stored information used to instruct the computer on what to do in response to input data.
  • RAM (random access memory) will store temporary information that can be read from or written to by the pP.
  • PROM (programmable read only memory) contains specific data that pertains to the exact vehicle in which the computer is installed.
  • EPROM (Erasable PROM) is similar to PROM except its contents can be erased to allow new data to be installed.
  • EEPROM (Electrically Erasable PROM) allows changing the information electrically one bit at a time.
  • NVRAM (Nonvolatile RAM) is a combination of RAM and EEPROM into the same chip.
  • Actuators are devices that perform the actual work commanded by the computer. They can be in the form of a motor, relay, switch, or solenoid.
  • A servomotor produces rotation of less than a full turn. A feedback mechanism is used to position itself to the exact degree of rotation required.
  • A stepper motor contains a permanent magnet armature with two, four, or more field coils. It is used to move the controlled device to whatever location is desired by applying voltage pulses to selected coils of the motor.