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IC Decap: Motorola MC68HC11E9 8-Bit Microcontroller

This particular IC came out of a very old VHF band radio, from the early 90’s. The die was encased in a custom ceramic package, like every other IC in the radio, with a custom part number. I managed to identify it from the markings on the silicon.

Motorola MC68HC11L6
Motorola MC68HC11L6

This was a pretty powerful MCU for it’s time, with 16K of onboard ROM, 512 bytes of both RAM & EEPROM, a 16-bit timer, 8-bit ADC, SPI & a MC68HC11 CPU core.

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No-Brand eBay Carbon Monoxide Detector

Chinese CO Alarm
Chinese CO Alarm

I was looking around eBay for decent deals on a branded CO alarm, and came across these for next to no money, so I thought I’d grab one just to see how bad they could be.

Alarm Opened
Alarm Opened

Popping the casing open shows the very small circuit board inside, with the CO sensor cell on the right. I can’t find any manufacturer information on this cell, nor can I find a photo of anything similar on the intertubes, so no specifications there. The other parts are pretty standard, a Piezo sounder & it’s associated step-up transformer to increase the loudness.

Sensor Closeup
Sensor Closeup

The sensor cell has the usual opening in the end to allow entry of gas.

Main PCB
Main PCB

The other side of the board doesn’t reveal much, just an LCD, a couple of LEDs, a pair of transistors, Op-Amp for the sensor & a main microcontroller.

MCU
MCU

The microcontroller isn’t marked unfortunately. It’s not had the number scrubbed off, it’s just never been laser marked with a part number. Above the micro is a SOT-23 LM321 low-power Op-Amp which does the signal conditioning for the CO sensor.

 

I tried to make this alarm trigger with the exhaust from the Eberspacher heater, which on a well-made branded alarm registered a reading of 154ppm after a few minutes. In the case of this alarm though, I couldn’t make it trigger at all, no matter how long I exposed it to hydrocarbon exhaust gases. I won’t be trusting this one then!

Nothing quite like a piece of safety equipment that doesn’t work correctly from new!

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Totally Wicked Forza / JoyeTech eVIC 60W Teardown

Display
Display

I’ve been a vaper now for many years, after giving up the evil weed that is tobacco. Here’s my latest acquisition in the vaping world, the JoyeTech eVIC 60W. This one is branded by Totally Wicked as the Forza VT60.

18650 Cell
18650 Cell

Powered by a single 18650 Li-Ion cell, this one is a Sony VTC4 series, 2100mAh.

Under the battery a pair of screws hold the electronics in the main cast alloy casing.

OLED Display
OLED Display

After removing the screws, the entire internal assembly comes out of the case, here’s the top of the PCB with the large OLED display in the centre.

USB Jack
USB Jack

On the right side of the board is the USB jack for charging & firmware updates. The adjustment buttons are also at this end.

Output
Output

On the left side of the board is the main output connector & the fire button. Unlike many eCigs I’ve torn down before, the wiring in this one is very beefy – it has to be to handle the high currents used with some atomizers – up to 10A.

PCB Reverse
PCB Reverse

Removing the board from the battery holder shows the main power circuitry & MCU. The aluminium heatsink is thermally bonded to the switching MOSFETs, a pair under each end. The switching inductor is under the gap in the centre of the heatsink.

DC-DC Converter
DC-DC Converter

A close up of the heatsink shows the very slim inductor under the heatsink.

Microcontroller
Microcontroller

The main MCU in this unit has a very strange part number, which I’ve been unable to find information on, but it’s probably 8081 based.