Thursday, 28 May 2015
In this video i do 90% teardown of a Robot Foto Traffipax TraffiPhot III-G Red Light traffic enforcement camera.
Used to enforce traffic lights throughout the world this is a common unit used by many countries.
At the top of the unit is the camera assembly, this is a SLR style body specifically designed for automated photography manufactured by Robot Foto, it has automatic exposure and motor drive along with data imprinting that allows the offending details (time, date, speed etc) to be recorded onto the film. Adjacent to that is a switched mode power supply with 5 and 12v.
There is a section of plug-in cards to control the machine, these are the loop interface card, display and control panel and five other cards that control the rest of the functions.
In the base of the unit is the flash power supply and flash tube.
A full video teardown can be seen on my YouTube Channel:
Tuesday, 26 May 2015
Found some missing video footage i took when i visited CERN when they had the CERN OpenDays during the LS1 (Long Shutdown 1).
The first part of the clip is one of the many substation sized electrical transformers located on the main site just off Route de Meyrin. They where making a lovely hum as i walked passed so grabbed my phone. It was too dark to read the specification plate unfortunately.
The second part is footage of the ATLAS detector.
Wednesday, 20 May 2015
Recently on the EEVblog forum there was discussion between several members having an electronics clear out at the Dunstable Downs Radio Club Bootsale.
The bootsale was located at Stockwood Park, near Luton, UK and is organised by the Dunstable Downs Radio Club so the mood was aimed more at the amateur radio sector but was applicable to anyone interested in electrical and electronic items.
The bootsale was predominately private individuals having a clear out with some traders also selling items. There was a huge variaty of items for sale from vintage consumer items like valve radios, ex military radio, amateur radio, general electronics and test / measurement equipment.
I picked up a few items, days like these are perfect for picking up small items that can be costly to buy mail order, so had a handful of BNC plugs and sockets, some small tools like tweezers.
One of the sellers had several high wattage power resistors mounted on large heatsinks, oviously out of some big dummy load setup so bagged the biggest one which consisted of 4x R2R 200W, 2x 1R 200W, 2x 10R 200W. The whole thing weighed about 10kg. I am sure these will prove useful at some point.
Saturday, 9 May 2015
I picked up two types of USB power bank when i was in Japan last year, the Panasonic QE-QL103-K (2900mah 1A) and a Panasonic QE-PL203-K (5800mah 1.5A & Qi Charging), the other day i was curious enough to break open the smaller of the two as i wanted to see how these branded, Japanese made power banks compare to the Chinese stuff you find on ebay.
the QE-QL103 costs about £12 from Yodobashi Camera, so is not an expensive item considering it will have a good quality Panasonic 18650 cell inside.
There is micro USB for charging and a standard USB for output to devices, handily it also includes a removable micro USB adaptor that can aid charging and connecting to your micro USB devices.
It was a bit of a struggle to open, i had thought it might have been ultrasonically welded but it actually has a screw and clips. I did break a few clips getting it apart and there is sticky tape on the battery which also holds the two parts of the case together making it a bit of a struggle to open without damaging the outer case.
I was surprised by the complexity of the controller board inside, containing an Atmel XMega16D4 loads of passives and smaller ICs. In the lower right corner there is some unpopulated components, these are likely for the slightly more expensive version (Panasonic QE-PL103-K) that has Qi charging. The bare terminals labelled LP01 and LP02 are probably for the pickup coil and the unpopulated BGA device above it would be the Qi controller.
The battery and board are soldered together looping through a plastic carrier so i can only get pics of one side of the board, i did consider de-soldering the battery to see the other side but i wondered if it might not power back up when reconnected (i use this charger every day!), there could be unknown startup procedures required when the battery is connected for the first time. Considering the micro controller has a minimum Vcc of 1.6v, well below the minimum cell voltage it is conceivable that it's not expected to ever power down the micro controller. The battery also has a temperature sensor glued to it.
One thing i did do was measure the battery voltage. It turns off at about 2.6v and charges upto 4.3v so they are really pushing the max out of the cell. One thing i did notice is it seems to not draw power out of the cell all the time, when powered on and supplying power to a USB device i saw the battery voltage dropping in steps so looks like they are drawing power from the cell in pulses.
If people are interested i could bridge the battery terminals so i can remove the plastic carrier without disconnecting the battery and get a view of the other side of the board and do some more in depth poking around?
Tuesday, 5 May 2015
Quick update, good new and bad, first the bad
The bad news; after taking a quick look at the Perkin Elmer Luminescence Spectrometer i have decided not to bother doing a video teardown a there is actually very little to see and i dont think will make interesting viewing but i will post some pictures up here of the internals, PCBs etc.
The good news is i have a TraffiPax TraffiPhot III-G 'Red Light' traffic camera that i will be doing a video teardown of. At the moment i am under the impression this was used at the Tile Shed Lane Railway Crossing (near Boldon, Tyne & Wear, UK).
Sunday, 3 May 2015
Recently i was measuring the resistance of a small transformer and saw an unusual problem with my Keysight U3401A Bench DMM.
By simply measuring the resistance of the windings on a small mains transformer when the measurement is taken and you remove the test lead from the transformer the DMM gets a small inductive kick from the transformer. This causes the DMM to display unusual numbers and work incorrectly.
The effect can be reset by changing measuring mode to volts and back to resistance or by power cycling the meter.
I would be interested to hear comments from those more experienced than i am about this. Could this be considered normal or is the DMM faulty of have poor design?
The effect is demonstrated in this video: