OverviewPlug-in meters can be used to easily measure and display the power consumption of electric appliances used in a household. Not only can plug-in meters measure the power consumption of each electric appliance, but they can also calculate the cost of electricity consumed, the amount of carbon dioxide, and other information. This has attracted the attention of energy and eco-conscious consumers wishing to reduce the wasteful use of power in their homes.
The power consumption of electric appliances ranges broadly from several watts to more than a thousand watts. Therefore, an A/D converter with a resolution of at least 10 bits is needed for measuring the current value that greatly influence power calculation. In addition, because plug-in meters are meant to be inserted between a commercial power supply and an electric appliance, small size and low weight are required. Furthermore, low cost is also an important factor for easing adoption by every household.
Renesas offers among others the RL78/L1x microcontrollers, which integrate on-chip the A/D converter required for power calculations and LCD driver for display, for use as main controllers, allowing external parts and cost to be reduced. In addition, we offer a rich semiconductor lineup including a variety of general-purpose ICs for use in current measurement or power supply, as well as EEPROM and other memory products for data storage, in order to meet our customers' needs.
System Block Diagram
|Block||Semiconductor device||Recommended products||Features, etc.|
|Main controller||MCU||RL78/L1x ||LCD driver, 10-bit A/D converter|
Ultra low power consumption
|R8C/Lx Series||LCD driver, 10-bit A/D converter|
|78K0R/Lx3 Series||LCD driver, 12-bit A/D converter|
|EEPROM||R1EX24xxx Series||I2C bus interface*1|
|R1EX25xxx Series||SPI bus interface*2|
|Power supply||Series regulator||UPC78L00 Series||Standard type|
|UPC29L00 Series||Low saturation type|
|General use, |
ircuit protection, etc.
|Zener diode||NNCDｘｘDA Series||High ESD tolerance optimal for use in surge absorption|
|RDｘｘS Series||2-terminal face-mount outline|
|Op-amp||UPC451||Quad op-amp for single power supply (low consumption)|
*1 I2C : Inter-Integrated Circuit
*2 SPI : Serial Peripheral Interface
Related Application Notes/Sample Code
|Renesas Starter Kit for R8C/L3AC||R0K52L3A0S000BE|
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