ESP8266 12E powered hardware with two relay outputs for connecting appliances. The appliances can be powered either by the Vin (DC) voltage source or an isolated external voltage source which can handle mains voltage. So, both low voltage and mains voltage appliances can be controlled using this device.
For this to work, the device needs to be connected to the same WiFi as that of the Amazon Alexa device.
After a little configuration in the alexa app and setting the correct WiFi name and password in the hardware, controlling an appliance is as simple as saying "Alexa switch on "
Serial pins and other ESP8266 pins are made accessible for reprogramming the device and adding peripheral functions.
Power Supplies / Uninterruptible Power Supplies (UPS)