Powerstrip Teardown

Powerstrip Teardown
Powerstrip Teardown
Powerstrip Teardown

I have been using this 10A(2.5KW) MX brand powerstrip for the last few years now. It’s decently built and has individual port control for switches. These ones come with a 5V USB charger port which delivers up to 1A of current. Since they are relatively cheap, wanted to check out the mechanism of the 220V to 5V generation part. I was expecting some very cheap.

Powerstrip Teardown
Powerstrip Teardown

The teardown process was straightforward (Just a few screws in the back). I think the PCB is made with the cheaper fibreglass equivalent of FR4 material and is one-sided. The circuit is fairly decently designed for the price they sell it at. The AC input is fed through a glass fuse and run through MB10F IC from Diodes Inc, which is a single chip full bridge rectifier to convert 220V AC to DC. This high voltage DC is fed to PN8335 IC which is a buck converter with active power factor correction. It has a tiny transformer providing some isolation to the DC side and provides the feedback to keep output at 5V. The high voltage DC is switched at high frequencies to generate the 5V after rectification at the output. This is similar to the circuits you would find in cheaper DC power adapters. To be honest, they have given a slot cut out for high voltage AC and DC sections so that’s nice.

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Raspberry Pi Pico W Analysis

Raspberry Pi Pico W
Raspberry Pi Pico W
Raspberry Pi Pico W
Raspberry Pi Pico W Teardown

A couple of days ago, Raspberry Pi Foundation released their new board Pico W for $6 which is an extension of the basic Pico board with wireless capabilities. It’s a big deal in the maker/hobby market because of the price. Now there is a good competitor to the ever-popular ESP32 series because of the wireless option. The board comes with WiFi for IoT applications.

Pico W contains the RP2040 chip which is a Cortex M0+ chip(one of the best in the class chip for the price of <$1, check posts of last year for detailed analysis on this chip) and to enable wireless capabilities they have partnered Infineon and used their CYW43439 dual-purpose wireless chip. It can do WiFi(2.4GHz) and Bluetooth 5.2. Currently, only WiFi is enabled on firmware but BLE support I am sure will soon follow. CYW43439 contains a dual-processor M3 and M4 for handling each of WiFi and BLE stack with a single physical antenna section handling both. Although it contains those processors, they are not application processors and are merely there for handling communication(Unlike Nordic’s BLE series). It needs a host controller to handle the application and transmit the data via high-speed SPI to it. If you check the PCB layout you can find the BGA wireless chip under the metal casing(Mostly for passing certification tests of EU and FCC) for the radio module with a dedicated crystal and 2.4GHz PCB antenna coming out of it.

I am sure folks from Arduino are starting to feel the heat with Rpi launching much cheaper boards. One thing it has going for it is its availability. I don’t know how on earth Rpi Foundation is able to have chips available in these days of shortage. It seems to be the only major brand out consistently having chips and boards. I do believe one key factor for that is the professional/industry is not using RP2040 in major products. It’s a decent chip but has its flaws(No Flash Memory, poor low power performance etc). Overall it’s a good maker board as an ESP32 alternative.

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