Several different power management techniques reduce the power consumption of grid-connected electronics and increase the battery life on portable products. Here are five examples of power management in action.
LONGER CELL PHONE USAGE
Motorola V360 (http://rbi.ims.ca/4400-541). This affordable cell phone has features normally found in more expensive units. These include video capture and playback, an integrated VGA camera, Push-To-Talk (PTT) functionality, Bluetooth wireless connectivity, an MP3 player, and expandable TransFlash memory. However, added features can significantly reduce talk time and the use of any of these functions, so power management is essential. With power supplied by a single lithium-ion battery, power management includes a boost converter that increases the voltage for displays and back lighting and several other voltage regulators for application processing, power amplifier, memory, wireless, and audio functions.
ENHANCED VIDEO DISPLAY
Daktronics ProStar VideoPlus Scoreboard (http://rbi.ims.ca/4400-542). On display in sports venues such as the Rogers Centre Ballpark in Toronto, Daktronics scoreboards use red, green, and blue (RGB) LED technology to present live and recorded video images. Daktronics' engineers chose Texas Instruments' TLC5940 16-channel, constant-current sink LED driver to enhance picture resolution, calibrate LED brightness, and improve power efficiency. Individually adjustable 12-bit grayscale pulse width modulation (PWM) control of each channel enhances color resolution. In addition, six-bit dot correction functionality compensates for the brightness variations between individual LEDs in the system and an integrated EEPROM stores the dot correction data. For more information on Texas Instruments' TLC5940 LED driver, go to http://rbi.ims.ca/4400-543.
SMART JUNCTION BOX
Yazaki Digital Power Module (DPM) (http://rbi.ims.ca/4400-544). The DPM used on vehicles such as the Chrysler CS (Pacifica) takes the traditional automotive junction box to the next level. The unit combines low-cost relays with short-circuit protected temperature field effect transistors (FETs) and smart FETS. With the lower on-resistance of today's FETs, the reduced power dissipation in the module allows the semiconductors to handle up to 20A circuits. This solid-state power switching provides fault tolerant functionality for subsystems and eliminates fuses in some circuits. Re-programming the software allows simple changes and upgrades. The DPM methodology enables the integration of several body control functions including exterior lighting, A/C, fuel pump, and load shedding into one module.
SureShot Dispensing Systems FlavorShot Dispenser (http://rbi.ims.ca/4400-545). The FlavorShot accurately dispenses concentrates for a variety of hot and cold beverages providing consistency and reducing costs. The unit's portion-control technology relies on Freescale Semiconductor's MM908E62x SMARTMOS IC. This IC has an integrated quad half H-bridge with power supply and an embedded MCU. The embedded HC08 MCU provides timing, sequencing, and control for the four 1-Ů half-bridge outputs that power the stepper motors in the dispenser. The integrated 5V, 60 mA voltage regulator provides a controlled power supply for the IC. For more information on Freescale's MM908E625, go to http://rbi.ims.ca/4400-546.
LONG LIFE CELL PHONE WITH INTEGRATED GPS
Wherify Wireless Wherifone (http://rbi.ims.ca/4400-547). Introduced as the world's smallest GSM/Enhanced-GPS Locator, this easy-to-use cell phone is only 81 x 40 x 17 mm. Since it operates on a GSM network, the unit typically knows the user's approximate position based upon the location of the GSM cell tower handling the call. By restricting the GPS satellite signal search to those satellites that are overhead, rather than searching for all 24 satellites in space, the GPS gets a fix sooner and consumes less energy in the process. This and other power management techniques allow the 600 mAh Lithium battery almost five days of standby power and approximately 100 locates per charge.