This is a TI "Smart" power strip reference design, used as a basis for developing intelligent metering and switched outlet domestic appliance power strips (a.k.a. Power boards).
With one IEC inlet and three IEC outlets, as well as a pass-through IEC connector for daisy-chaining, this design incorporates an MSP430i2040 microcontroller for managing the three switched outlets, and measuring current, voltage and phase of each of the three loads. The microcontroller firmware has been developed to allow metering for data-logging of power usage of applied loads, as well as allow for protection by setting thresholds for overvoltage and brown-out (undervoltage), as well as current limit, for each attached individual load.
This design incorporates:
- MSP430i2040 Ultra-low-power MCU
- SMD power resistors for current shunts
- IEC inlets and outlets (can be applied universally)
- CUI 5V switching power supply on-board for powering low voltage microcontroller
- Two 16-Amp load switch relays
- One 16-Amp latching relay
- Debug interface for testing firmware
- Serial interface for in-app communication to the power strip
It's important to point out that the MCU debug interface, as well as the serial communications interface to the MCU, are NON ISOLATED. Therefore for testing and development the power strip should NOT be connected to live mains wiring, but be used with an ELV isolated transformer based AC power supply.
The serial port (UART interface) is also non-isolated. For final in-situ development, an isolated serial module incorporating opto-isolators can be used, or a WiFi-to-UART module, or BLE module. TI has also produced reference designs for these modules in concert with the Smart Strip Reference Design here. (These will also be provided in CircuitMaker - stay tuned).