chipset – Experimental Engineering

Posted on October 20, 2016 by The Engineer — Leave a comment

Tenma 72-10405 DMM Teardown

Well it’s time for a new DMM. After the last pair of eBay El-Cheapo Chinese meters just didn’t last very well, I decided a proper meter was required. This one is a Tenma 72-10405, stocked by Farnell for under £60. Not quite as many festures as the cheapo Chinese meters, but I expect this one to be a bit more reliable.

Since I can’t have anything without seeing how it’s put together, here’s the inside of the DMM. (Fuse access is only possible by taking the back cover off as well. The 9v PP3 battery has a seperate cover).

He’s the input section of the meter, with the 10A HRC fuse & current shunt for the high-amps range. The other fuse above is for the mA/µA ranges. The back cover has a wide lip around the edge, that slots into a recess in the front cover, presumably for blast protection if the meter should meet a sticky end. The HRC fuses are a definite improvement over the cheap DMMs, they only have 15mm glass fuses, and no blast protection built into the casing.
There are some MOVs for input protection on the volts/ohms jack, the jacks themselves are nothing more than stampings though.

Not much at the other side of the board, there’s the IR LED for the RS232 interface & the beeper.

Most of the other components are on the other side of the PCB under the LCD display. The range switch is in the centre, while the main chipset is on the left.

The chipset of this meter is a FS9922-DMM3 from Fortune Semiconductor, this is a dedicated DMM chipset with built in ADCs & microcontroller.

Posted on July 8, 2012 by The Engineer — Leave a comment

Cisco 2G Fibre Channel SFP Module

2G Fibre Tranciever — 2G Fibre Transceiver

Here is a 2Gbit Fibre Channel transceiver from Cisco Systems in SFP module format.

Here the shield has been removed from the bottom of the module (it just clips off). The bottom of the PCB can be seen, with the copper interface on the left & the rubber boots over the photodiode & 850 nm laser on the right.

Here the PCB has been completely removed from the frame, the fibre ends slide into the rubber tubes on the right.

Top of the PCB, showing the chipset. There are a pair of adjustment pots under some glue, next to the chipset, presumably for adjusting laser power & receive sensitivity. The laser diode & photodiode are inside the soldered cans on the right hand side of the board, with the optics required to couple the 850nm near-IR light into the fibre.

Posted on July 12, 2011 by The Engineer — Leave a comment

Sigma Mini Keychain LCD Photoframe

This is a cheap Sigma branded keychain photoframe. User buttons for power & selecting photos are on the left.
There are two white LEDs on the bottom edge that function as a torch as well.

Front of the unit removed, showing the LCD module. The USB jack is bottom left, next to the pair of white LEDs & above that is the 32kHz watch crystal that the CPU uses for timekeeping.

Here the back has been removed showing the 3.7v Li-Ion cell used to provide power.

Here the display has been removed from the PCB exposing the chipset.

Here the CPU blob-top chip & a flash memory IC are visible. The CPU is a Sitronix ST2205U.

Posted on February 24, 2011February 10, 2011 by The Engineer — Leave a comment

PCMCIA Ethernet Card

An old Xircom Ethernet card for a laptop. This uses the old 50 pin PCMCIA interface.

Rear of the card with the MAC address & card spec details.

PCB removed from the outer shield. Xircom ethernet chipset centre. Special socket on the right fits a RJ-45 adaptor lead.

Posted on February 20, 2011February 10, 2011 by The Engineer — Leave a comment

Garmin eTrex

Pocket sized GPS navigator. Here is shown the greyscale dot matrix LCD.

Serial interface on the back of the unit. Pinout from left is +3v, Rx, Tx, GND.

PCB Removed from the casing. RTC backup battery in the centre of board, CPU & flash ROM on the left. GPS chipset is under the shield on the right.

Front of the PCB, GPS antenna on the right, LCD panel left.

LCD folded back from the PCB. Driver IC can be seen attached to the ribbon.

LCD Panel backlight. Requires 200v AC at 20kHz to glow green.

GPS chipset with the shield removed.

Posted on January 4, 2011January 3, 2011 by The Engineer — Leave a comment

PSP Slim

Here is a PSP Slim that recently died.

For those that are interested, here is the ID label, this is a PSP-2003.

Here the front of the unit has been removed, showing the first internal components.

Here is the unit with the LCD removed, here the mainboard is partially visible.

Left pad unit removed from the PSP, with the left speaker & the memory stick slot cover.

Rear of the left pad assembly, showing the speaker.

Joypad removed from the casing. Resistive unit.

Headphone/data board removed from the casing. This also has TV-Out on the PSP-200x series.

Mainboard removed. Main CPU is at the top. Sockets around the bottom connect to the UMD drive & UMD Drive.

Closeup of the main chipset. CPU is the top IC.

Rear of the mainboard, Memory Stick socket on the right.

Closeup of the WiFi chipset & the charging power socket on the right.

Closeup of the bettery connector & the charge controller IC.

UMD Drive removed from the rear of the casing. This is a miniature DVD style drive, using a 635nm visible red laser.

Rear of the UMD drive, showing the laser sled & drive motors. Both the spindle motor & the sled motor are 3-phase brushless type. The laser diode/photodiode array is at the top of the laser sled.

Posted on December 10, 2010 by The Engineer — Leave a comment

Belkin PCMCIA Wi-Fi Card

Here is an old Belkin Wireless G network card. This is a PCMCIA version.

Here is the bottom of the device, with all the details.

Plastic antenna cover removed, showing the pair of 2.4GHz etched antennae. There is a pair of LEDs on the upper left of the PCB showing activity & link status.

Overall view of the PCB, antennae on the left, RF chipset in centre, WiFi controller IC on right, and PCMCIA socket on far right. Can below wireless controller is a quartz crystal for the clock.

Closeup of the chipset, a Ralink RT2560F wireless controller on the right & a RT2525L transceiver on the left.