laptop – Experimental Engineering

Posted on August 17, 2017August 16, 2017 by The Engineer — 2 Comments

EpEver MT50 Control Panel Teardown

Here’s the MT50 controller from EpEver, that interfaces with it’s Tracer MPPT solar charge controllers, and gives access to more programming options on the charge controllers, without the need for a laptop. The display is a large dot-matrix unit, with built in backlight. Above is the display on the default page, showing power information for the entire system.

The rear plastic cover is held in place by 4 machine screws, which thread into brass inserts in the plastic frame – nice high quality touch on the design here, no cheap self tapping plastic screws. Both power & data arrive via an Ethernet cable, but the communication here is RS-485, and not compatible with Ethernet! The PCB is pretty sparse, with comms & power on the left, LCD connection in the centre, and the microcontroller on the right.

On the left of the board is the RS0485 transceiver, and a small voltage regulator. There’s also a spot for a DC barrel jack, which isn’t included in this model for local power supply.

The other side of the board holds the main microcontroller which communicates with the charge controller. This is a STM32F051K8 from ST Microelectronics. With a 48MHz ARM Cortex M0 core, and up to 64K of flash, this is a pretty powerful MCU that has very little to do in this application.

The front of the PCB has the ENIG contacts of the front panel buttons, and the LCD backlight assembly. There’s nothing else under the plastic backlight spreader either.

The front case holds the LCD module in place with glue, and the rubber buttons are placed underneath, which is heat staked in place.

The LCD is a YC1420840CS6 from eCen in China. Couldn’t find much out about this specific LCD.

Posted on May 29, 2016 by The Engineer — 4 Comments

TS100 12-24v Soldering Iron

When I ordered the tiny USB soldering iron, I decided a proper iron upgrade would be a good idea. Looking around for something that didn’t require AC mains power turned up the TS100, a Chinese design, that unusually is actually very good! Above is the handle itself, with it’s small OLED display & two operation buttons.
This iron is controlled by a STM32 ARM microcontroller, the firmware & schematics are completely open-source.

The bottom end of the iron has the main DC input jack, designed with laptop chargers in mind (DC input range from 10v-24v). Above that is the micro USB port for programming.

The iron tips slot into the other end, many different tip types & shapes are available. The one supplied was the simple conical tip.

Plugging the iron into some power gets a standby screen – it doesn’t just start heating immediately, for safety.

The left hand button starts the heater, which on a 24v input voltage gets to operating temperature well within 10 seconds.

The right hand screen icon changes when the temperature has stabilized. The control PCB has an integrated accelerometer, leaving the iron hot for a few minutes triggers a timeout & it powers down. Once picked up again, the heater instantly restarts.
The operating temperature is adjustable with the pair of buttons, from 100°C to 400°C.

Here’s a selection of bits for the iron. The design is very similar to the Hakko T15 series of irons, but these are a much shorter version. Like the Hakko versions, the actual tips aren’t replaceable, once the bit burns out, the entire assembly is replaced.

Here’s the iron fully assembled. The entire device is about the same length as just the heating element from a Hakko T15!

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 3, 2011February 10, 2011 by The Engineer — Leave a comment

Daily Photo 3/2/2011

Motherboard from an old HP laptop. AMD Chipset. Model unknown.

Posted on July 29, 2010August 1, 2010 by The Engineer — Leave a comment

Western Digital 160GB 2.5″ HDD

This is a Western Digital drive recently removed from my laptop when it died of a severe head crash.
Top of drive can be seen here.

Here the cover has been removed from the drive, showing the platter, head arm & magnet. Yellow piece top left is head parking ramp.

The head assembly of the drive is shown here. The head itself is on the left hand end of the arm in the plastic parking ramp. The other end of the arm holds the voice coil part of the head motor, surrounded by the magnet.

Bottom of drive, with controller PCB. SATA interface socket at bottom.

PCB removed from bottom of drive. Spindle motor connections & connections to the head unit can be seen on the bottom of the drive unit.

Controller PCB. Supports the cache, interface & motor controller ICs.

Closeup of the motor driver IC, this controls the speed of the spindle motor precisely to 5,400RPM. Also controls the voice coil motor controlling the position of the head arm on the platters.

Interface IC closeup. This IC receives signals from the head assembly & processes them for transmission to the SATA bus. Also holds drive firmware, controls the Motor driver IC & all other functions of the drive.

Cache Memory IC.