Here’s a destructive teardown of an automotive in-tank turbine fuel pump, used on modern Petrol cars. These units sit in the tank fully immersed in the fuel, which also circulates through the motor inside for cooling. These pumps aren’t serviceable – they’re crimped shut on both ends. Luckily the steel shell is thin, so attacking the crimp joint with a pair of mole grips & a screwdriver allowed me inside.
End Bell
The input endbell of the pump has the fuel inlet ports, the channels are visible machined into the casting. There’s a pair of channels for two pump outputs – the main fuel rail to the engine, and an auxiliary fuel output to power a venturi pump. The fuel pump unit sits inside a swirl pot, which holds about a pint of fuel. These are used to ensure the pump doesn’t run dry & starve the engine when the tank level is low & the car is being driven hard. The venturi pump draws fuel from the main tank into the swirl pot. A steel ball is pressed in to the end bell to provide a thrust bearing for the motor armature.
Turbine Impeller
The core of the pump is this impeller, which is similar to a side-channel blower. From what I’ve been able to find these units supply pressures up to about 70PSI for the injector rail. The outside ring is the main fuel pump, while the smaller inner one provides the pressure to run the venturi pump.
Pump Housing
The other side of the machined pump housing has the main output channel, with the fuel outlet port at the bottom. The motor shaft is supported in what looks like a carbon bearing.
Midsection
Removing the pump intermediate section with the bearing reveals quite a bit of fungus – it’s probably been happy sat in here digesting what remains of the fuel.
Armature Exposed
Some peeling with mole grips allows the motor to come apart entirely. The drive end of the armature is visible here.
Motor Can
The outer shell of the motor holds yet more fungus, along with some rust & the pair of ceramic permanent magnets.
Brushes
The other end of the pump has the brush assembly, and the fuel outlet check valve to the right. The bearing at this end is just the plastic end cap, since there are much lower forces at this end of the motor. The fuel itself provides the lubrication required.
Potted Armature
With the armature pulled out of the housing, it’s clear that there’s been quite a bit of water in here as well, with the laminations rusting away. This armature is fully potted in plastic, with none of the copper windings visible.
Carbon Commutator
The commutator in these motors is definitely a strange one – it’s axial rather than radial in construction, and the segments are made of carbon like the brushes. No doubt this is to stop the sparking that usually occurs with brushed motors – preventing ignition of fuel vapour in the pump when air manages to get in as well, such as in an empty tank.
For years now I’ve used Virtualmin for my hosting requirements, and have made use of Procmail to filter my mail into folders (it’s the default, and rather tightly integrated). The only issue with this system is having to login to two different things for mail: I use Rainloop Webmail for general mail viewing, but the Procmail filters are only editable through the Usermin section of Virtualmin. This is awkward to say the least, so being able to use Sieve which is already supported by Rainloop is a better option. (Sieve is also supported via plugin in Roundcube).
Since we’re going to still need Procmail for the Virtualmin-managed Spam & Virus scanning functions, we will add Sieve at the end of Procmail. There are some
First thing, get Sieve installed via Dovecot, with the following:
yum install dovecot-pigeonhole
Some configuration changes are required to Dovecot to get the Sieve server running, /etc/dovecot/conf.d/15-lda.conf should have this section:
protocol lda {
# Space separated list of plugins to load (default is global mail_plugins).
mail_plugins = sieve
}
Finally, in /etc/dovecot/conf.d/20-managesieve.conf, uncomment this section to enable the managesieve server:
service managesieve-login {
inet_listener sieve {
port = 4190
}
}
After these changes are made, restart Dovecot to get the configs reloaded. It’s easy to check if the Sieve server is listening by running the following command:
I’m making some changes to my hosting services, I’ve been testing Sentora, as it’s much more user friendly, if a little more limited in what it’s capable of doing, vs my go-to admin panel over the past 6+ years, Virtualmin.
I noticed that SpamAssassin isn’t set up on a Sentora server by default, so here’s a script that will get things working under a fresh Sentora install in CentOS 7:
After this script has run, some mail server settings will be changed, and the master.cf configuration file for Postfix will be backed up just in case it craps out.
Make sure the SpamAssassin daemon is running on port 783 with this command:
ss -tnlp | grep spamd
Testing is easy, send an email to an address hosted by Sentora with the following in the subject line:
If SpamAssassin is working correctly, this will be tagged with a spam score of 999.
A useful script is below, this trains SpamAssassin on the mail in the current server mailboxes. I’ve been using a version of this for a long time, this one is slightly modified to operate with Sentora’s vmail system. All mail for all domains & users will be fed into SpamAssassin in this script. I set this to run nightly in cron.
#!/bin/bash
#specify one or more users, space padded [user=(user1 user2 user3)] or empty [user=()] to include all users. All users is considered uid ≥ 1000.
user=(vmail)
#After how many days should Spam be deleted?
cleanafter=30
#backup path, comment out to disable backups
bk=/home/backup/sa-learn_bayes_`date +%F`.backup
log=/var/log/train-mail.log
#log=/dev/stdout
echo -e "\n`date +%c`" >> $log 2>&1
if [ -z ${user[@]} ]; then
echo user is empty, using all users from system
user=(`awk -F':' '$3 >= 1000 && $3 < 65534' /etc/passwd |awk -F':' '{print $1}'`)
fi
for u in ${user[@]}; do
if [ ! -d /var/sentora/vmail/*/* ]; then
echo "No such Maildir for $u" >> $log 2>&1
else
echo "Proceeding with ham and spam training on user \"$u\""
#add all messages in "junk" directory to spamassassin
echo spam >> $log 2>&1
#change this path to match your spam directory, in this case its "Junk"
#add current and new messages in Junk directory as spam
sa-learn --no-sync --spam /var/sentora/vmail/*/*/.Junk/{cur,new} >> $log 2>&1
echo ham >> $log 2>&1
#only add current mail to ham, not new. This gives user a chance to move it to spam dir.
sa-learn --no-sync --ham /var/sentora/vmail/*/*/{cur} >> $log 2>&1
fi
done
#sync the journal created above with the database
echo sync >> $log 2>&1
sa-learn --sync >> $log 2>&1
if [ $? -eq 0 ]; then
for u in ${user[@]}; do
echo "deleting spam for $u older than 30 days" >> $log 2>&1
find /var/sentora/vmail/*/*/.Junk/cur/ -type f -mtime +$cleanafter -exec rm {} \;
done
else
echo "sa-learn wasn't able to sync. Something is broken. Skipping spam cleanup"
fi
echo "Statistics:" >> $log 2>&1
sa-learn --dump magic >> $log 2>&1
echo ============================== >> $log 2>&1
if [ -n $bk ]; then
echo "backup writing to $bk" >> $log 2>&1
sa-learn --backup > $bk
fi
Time for another teardown! Here’s a pocket-sized headphone amplifier for use with mobile devices. This unit is powered by a built-in lithium cell, and can give some pretty impressive volume levels given it’s small size.
Audio Connections
The 3.5mm audio input & output jacks are on the front of the unit, along with the relatively enormous volume knob & power switch. There’s a little blue LED under the switch that lets the user know when the power is on, but this is a very sedate LED, using very little power.
Gain & Charging
On the back is the High-Low gain switch, and the µUSB charging port. There’s another indicator LED to show that the internal cell is charging, in this case a red one.
PCB Top
Removing a couple of cap screws allows the internals to slide out of the extruded aluminium casing. Most of the internal space is taken up by the 1Ah lithium cell, here on the top of the PCB secured by some double-sided tape. The volume potentiometer is mounted on a small daughterboard at right angles to get it to fit into the small vertical space in the case.
PCB Rear
The bottom of the PCB is equally as sparse – the only ICs being the main audio amp in the centre & the battery charger IC at the top.
Amplifier IC
The main audio amplifier is a TP9260, I couldn’t find a datasheet on this, so I’m unsure of what the specs are. The row of resistors above the IC are for the gain divider circuit. There’s also a pogo pin on the right that makes contact with the back panel of the case for grounding.
Battery Charger
Battery charging is taken care of by a UN8HX 500mA linear charging IC, not much special here.
This little amplifier seems to be pretty well made, considering the price point. The only issue I’ve had so far is the audio cables act like antennas, and when in close proximity to a phone some signal gets picked up & blasted into the headphones as interference.
Here’s an eBay oddity – it’s got the same light & lens mechanism as the cheap “disco light” style bulbs on eBay, but this one is battery powered & has a built in MP3 player.
MP3 Disco Light
This device simply oozes cheapness. The large 4″ plastic dome lens sits on the top above the cheap plastic moulding as a base, which also contains the MP3 player speaker.
Controls
There are few controls on this player, the volume buttons are combined with the skip track buttons, a long press operates the volume control, while a short press skips the tracks. Several options for getting this thing to play music are provided:
Bluetooth – Allows connection from any device for bluetooth audio
USB – Plugging in a USB flash drive with MP3 files
SD Card – Very similar to the USB flash drive option, just a FAT32 formatted card with MP3 files
Aux – There’s no 3.5mm jack on this unit for an audio input, instead a “special” USB cable is supplied that is both used to charge the built in battery & feed an audio signal. This is possible since the data lines on the port aren’t used. But it’s certainly out of the ordinary.
Top Removed
The top comes off with the removal of a single screw in the centre of the lens. The shaft in the centre that holds the lens is attached to a small gear motor under the LED PCB. There’s 6 LEDs on the board, to form an RGB array. Surprisingly for a very small battery powered unit these are bright to the point of being utterly offensive.
Mainboard
Here’s the mainboard removed from the plastic base. There’s not much to this device, even with all the options it has. The power switch is on the left, followed by the Mini-B USB charging port & aux audio input. The USB A port for a flash drive is next, finishing with the µSD slot. I’m not sure what the red wire is for on the left, it connects to one of the pins on the USB port & then goes nowhere.
Audio Amplifier
The audio amplifier is a YX8002D, I couldn’t find a datasheet for this, but it’s probably Class D.
Main Chipset
Finally there’s the main IC, which is an AC1542D88038. I’ve not been able to find any data on this part either, it’s either a dedicated MP3 player with Bluetooth radio built in, or an MCU of some kind.The RF antenna for the Bluetooth mode is at the top of the board.
Just behind the power switch is a SOT23-6 component, which should be the charger for the built in Lithium Ion cell.
Lithium Ion Cell
The cell itself is a prismatic type rated in the instructions at 600mAh, however my 1C discharge test gave a reading of 820mAh, which is unusual for anything Li-Ion based that comes from eBay 😉
There is cell protection provided, it’s under the black tape on the end, nothing special here.
The main issue so far with this little player is the utterly abysmal battery life – at full volume playing MP3s from a SD card, the unit’s current draw is 600mA, with the seizure & blindness-inducing LEDs added on top, the draw goes up to about 1200mA. The built in charger is also not able to keep up with running the player while charging. This in all only gives a battery life of about 20 minutes, which really limits the usability of the player.
I’ve been running my own VPN so I can access my home-based servers from anywhere with an internet connection (not to mention, in this day & age of Government snooping – personal privacy & increased security).
I’m on a pretty quick connection from Virgin Media here in the UK, currently the fastest they offer:
Virgin Media
To do these tests, I used the closest test server to my VPN host machine, in this case Paris. This keeps the variables to a minimum. Testing without the VPN connection gave me this:
Paris Server Speed
I did expect a lower general speed to a server further away, this will have much to do with my ISP’s traffic management, network congestion, etc. So I now have a baseline to test my VPN throughput against.
The problem I’ve noticed with OpenVPN stock configs are that the connections are painfully slow – running over UDP on the usual port of 1194 the throughput was pretty pathetic:
Stock Config Speed
I did some reading on the subject, the first possible solution being to change the send/receive buffers so they’re set to a specific value, rather than letting the system handle them. I also added options to get the server to push these values to the clients, this saving me the trouble of having to reissue all the client configurations.
Unfortunately just this option didn’t work as well as I’d like, downstream speeds jumped to 25Mb/s. In the stock config, the tunnel MTU & MSSFIX settings aren’t bothered with, some adjustment to set the tunnel MTU to lower than the host link MTU (in my case the standard 1500) prevents packet fragmentation, MSSFIX let’s the client TCP sessions know to limit the packet sizes it sends so that after OpenVPN has done the encryption & encapsulation, the packets do not exceed the set size. This also helps prevent packet fragmentation.
tun-mtu 1400
mssfix 1360
VPN Tweaked
After adjusting these settings, the download throughput over the VPN link has shot up to 136Mb/s. Upload throughput hasn’t changed as this is limited by my connection to Virgin Media. Some more tweaking is no doubt possible to increase speeds even further, but this is fine for me at the moment.
Here’s a piece of medical equipment that in recent years has become extremely cheap, – a Pulse Oximeter, used to determine the oxygen saturation in the blood. These can be had on eBay for less than £15.
Powered On
This one has a dual colour OLED display, a single button for powering on & adjusting a few settings. These cheap Oximeters do have a bit of a cheap plastic feel to them, but they do seem to work pretty well.
Pulse Oximeter
After a few seconds of being applied to a finger, the unit gives readings that apparently confirm that I’m alive at least. 😉 The device takes a few seconds to get a baseline reading & calibrate the sensor levels.
Main PCB Top
The plastic casing is held together with a few very small screws, but comes apart easily. here is the top of the main board with the OLED display panel. There appears to be a programming header & a serial port on the board as well. I’ll have to poke at these pads with a scope to see if any useful data is on the pins.
Main PCB Bottom
The bottom of the board has all the main components of the system. The microcontroller is a STM32F03C8T6, these are very common in Chinese gear these days. There’s a small piezo beeper & the main photodiode detector is in the centre.
There is an unpopulated IC space on the board with room for support components. I suspect this would be for a Bluetooth radio, as there’s a space at the bottom left of the PCB with no copper planes – this looks like an antenna mounting point. (The serial port on the pads is probably routed here, for remote monitoring).
At the top left are a pair of SGM3005 Dual SPDT analogue switches. These will be used to alternate the red & IR LEDs on the other side of the shell.
A 4-core FFC goes off to the other side of the shell, bringing power from the battery & supplying the sensing LEDs.
Battery Compartment
Power is supplied by a pair of AAA cells in the other shell.
Dual LED
The sensor LEDs are tucked in between the cells, this dual-diode package has a 660nm red LED & a 940nm IR LED.
A lot of the electronics I use & projects I construct use batteries, mainly of the lithium variety. As charging this chemistry can be a little explosive if not done correctly, I decided a proper charger was required. This charger is capable of handling packs up to 6 cells for Lithium, and up to 20v for lead-acids.
External Connections
The usual DC input barrel jack on the left, with an external temp sensor for fast charging NiCd/NiMH chemistry batteries. The µUSB port registers under Linux as USB HID, probably so drivers aren’t required. Unfortunately the software is Windows only, but it doesn’t provide anything handy like charging graphs or stats. Just a way to alter settings & control charging from a PC. On other versions of this charger there’s a setting to change the temp sensor port into a TTL serial output, which would be much handier.
Output & Balance
The other side of the charger has the main DC output jacks & the pack balancing connections.
Cover Removed
Here’s the top cover removed from the charger, showing most of the internals. A standard HD44780 LCD provides the user interface, the CPU & it’s associated logic is hidden under there somewhere.
The PCB has nice heavy tracks to handle the 6A of current this charger is capable of.
Balancing Network
The output side of the board. Here the resistive pack balancing network can be seen behind the vertical daughter board holding the connectors, along with the output current shunt between the DC output banana jacks & the last tactile button.
Main Logic
Unfortunately the LCD is soldered directly to the board, and my desoldering tool couldn’t quite get all the solder out, so time to get a bit violent. I’ve gently bent the header so I could see the brains of the charger. The main CPU is a Megwin MA84G564AD48, which is an Intel 8081 clone with USB support. Unfortunately I was unable to find a datasheet for this part, and the page on Megwin’s site is Chinese only.
I was hoping it was an ATMega328, as I have seen in other versions of this charger, as there are custom firmwares available to increase the feature set of the charger, but no dice on this one. I do think the µUSB port is unique to this version though, so avoiding models with that port probably would get a hackable version.
There’s some glue logic for controlling the resistor taps on the balancing network, and a few op-amps for voltage & current readings.
Power Switching Devices
All the power diodes & switching FETs for the DC-DC converter are mounted on the bottom of the PCB, and clamped against the aluminium casing when the PCB is screwed down. Not the best way to ensure great contact, but Chinese tech, so m’eh.
In my previous post, I mentioned I’d be replacing the factory supplied charging gear with something that actually charges lithium chemistry cells correctly.
Charging Base
Here’s the base as supplied, with an indicator LED on the right hand side. This LED indicates nothing other than power being applied to the charging base. It’s just connected across the power input with a resistor. This also means that any battery left in the charger while it’s unplugged will discharge itself through this LED over time. Great design there China!
PCB Removed
Here I’ve removed the PCB – there’s no need for it to be taking up any space, as it’s just a complete waste of copper clad board in the first place. The battery tabs have been desoldered & hot snot used to secure them into the plastic casing.
USB Hole
The charger modules I use are USB powered, so a small hole has been routed out in the casing to allow access to the port.
Charging Module
Here the charging module has been installed & wired to the battery tabs. Output is now a nice 4.18v, and will automatically stop charging when the cell is full.
Safety has been restored!
While sourcing the main propulsion hydraulic system for nb Tanya Louise in the summer, we thought that it would be convenient to have an on board generator that didn’t require dragging off the boat & highly explosive petrol to operate.
As the hydraulics were already being fitted, we decided to add a hydraulically driven generator to solve this issue.
And this is where the problems began…
We were referred to Mike Webb of hydraulicgenerators.co.uk to supply the equipment required for this part of the project, this was to include the alternator itself, hydraulic motor to drive the alternator, the required adaptor plates to mate the motor to the generator head & a control valve block to regulate the oil flow & pressure to the motor.
After a phone call to Mike on 16-07-2013 to discuss our requirements, we settled on a system. I received the following E-Mail the next day from Mike:
Good morning, reference our conversation, Martin from BSP has given me details as to what he will be supplying, on that basis and in light of the special price I have offered, this is what I propose to supply,
1 off New 8kVa – 7kW Hydraulic driven generator 220v single phase 50hz c/w flow control valve, pressure relief valve and on/off solenoid valve, Martin did say that the engine idle is between 1000 and 1200 rpm and max speed is 3600 rpm, valves will be rated accordingly. I have the alternator and parts available now, in order for me to be able to offer this at a significantly discounted price of £ 1.200.00 nett, I will need to utilise the components I have in stock now, so I will need payment asap, delivery will be approx. 7 days, primarily due to the fact that the coupling is fabricated to suit, I can either deliver the unit to you when ready or BSP or hold onto it until everything else is in place. The alternator is a Meccalte S20W that I bought for another customer a few weeks ago, but he cancelled and I don’t have, at this time, anyone else interested in it, so either I do a deal with you at the above price or wait until someone else comes along and wants the unit.
With regards to installation, let me know if you need any help, but it would be best to install when the engine is being installed and the rest of the system hosed up, I assume BSP will be sorting this, in which case I’ll liase with Martin.
I trust that this meets with your approval and look forward to hearing from you.
At this point an order was placed with Mike, & the money transferred so he could begin building the unit for us. As can be seen from the E-Mail, a lead time of 7 days was stated.
After a few phone calls over the following month, firstly being told that the custom parts to mate the generator to the motor had not come back from the engineers, I sent another E-Mail to Mike on 10-09-2013, and got no reply.
Following another phone call, I was told that the generator had been shipped, however Mike would not give me any tracking details for the shipment, and would not initially tell me who it was shipped with.
Again the generator didn’t turn up.
More phone calls ensued & I was told at this point that the shipping company had been confused by the address given, shipped back to Mike. At this point I was informed that the shipping company had actually LOST it. Several more phone calls later I was promised that a replacement generator would now ship no later than 08-10-2013. A follow up E-Mail two days later also generated no reply.
At this point I was beginning to wonder if I would ever see the goods we had paid for, but finally a shipment arrived from Mike
~15-10-2013, over TWO MONTHSafter our promised delivery date. However, even having been delivered, all was not well with the goods.
Generator Pallet
Above is the generator supplied. No mounting bracket, no integrated valve block, in short, nothing like what was described in Mike’s documentation & website. The original documentation is available here for reference: [download id=”5564″]
As can be seen, there is an open port on the side of the valve block. This is where the ON/OFF control solenoid valve is supposed to be located.
After several more unanswered E-Mails & phone calls, I had to get somewhat more forceful in my messages, as now Mike had begun outright lying about what was specified in the original order. In which that there was no solenoid valve required. So the following E-Mail was sent 21-10-2013:
Mike,
Having had a conversation with Martin, about him attempting to contact you regarding what you have supplied to us, I need this resolving ASAP now, as I am being held up by the fact that there is an open port on your valve block where the solenoid control valve is supposed to be located.
As it stands the valve block & therefore the generator you have supplied to us is useless for it’s intended purpose & I will be seeking legal advice on this matter if a resolution cannot be made this week, considering you have not replied to any E-Mail I have sent since the unit’s massively delayed arrived.
In your original correspondence it is certainly indicated that this valve was to be fitted, which was also Martin’s instruction to you.
I await your expedient response.
This threat of legal action actually spurred a response from Mike, who finally replied with the following on 25-10-2013:
Ben,
Sorry about all this, I have been away and down with a bug for the last week, I will sort this today and will have the required parts shipped to you on Monday for Tuesday delivery.
Regards
Mike
Another promise of a delivery date, so I waited a little longer, until the Friday of that week. Still no delivery. No surprise there then.
(I didn’t believe the story about illness either).
At this point I again attempted contact, but got nowhere, even with legal threats. So I’ve given up completely on this & been forced to source the parts elsewhere at extra cost.
This company is not the one to go to if you require a hydraulic generator unit for any application, as you’d be lucky to get any part of what you order on time, if at all.
Operations are run by an all out liar who seems to be happy to accept money but not ship the goods that had been paid for.
Mike having explained to me that the shipping company had lost a generator, and he would have to build me another one to replace it also does not make sense, as in the initial phone call & mail he stated that the Meccalte generator that we eventually received was a single unit that was specially ordered for another client, and the factory build date on the unit certainly gave away the fact that the generator head had been sat around for some considerable time before I came along & made a purchase.
Hopefully this post will get a high Google ranking, to ensure that anyone else who happens to be looking for a similar piece of equipment does not have the misfortune to trust this man.
We were referred to him on good faith & unfortunately in this case it did not go well.
These speakers are available free from Pringles, with two packs bought. Normally running on 3x AAA cells, I have made modifications to include a high capacity Li-Ion battery & USB charging.
18650 Battery
New battery is 3x 18650 Li-Ion cells in parallel, providing ~6600mAh of capacity. These are hot glued inside the top of the tube under the speaker, with the charging & cell protection logic.
The battery charging logic is salvaged from an old USB eCig charger, these are single cell lithium chargers in a small form factor ideal for other uses. Charging current is ~450mA.
Amplifier Board
The cells are connected to the same points as the original AAA cells, with the other pair of wires going into the top of the device to connect to the MicroUSB charging port.
The amplifier in this is a LM4871 3W Mono amplifier IC, connected to a 6Ω 1W speaker.
The other IC on the board is unidentifiable, but provides the flashing LED function to the beat of the music.
Here’s my latest project with the Pi: interfacing it with the Sparkfun Geiger counter & outputting the resulting data to a character LCD.
The geiger counter is interfaced with it’s USB port, with the random number generator firmware. A Python script reads from the serial port & every minute outputs CPM & µSv/h data to the display.
The Python code is a mash of a few different projects I found online, for different geiger counters & some of my own customisations & code to write the info to the display & convert CPM into µSv/h.
This also writes all the data into a file at /var/log/radlog.txt
The hub for the external USB ports has been fitted here, with the two ports hardwired to the pads where once there were USB A sockets. This hub will also accommodate the wireless receiver for the mini keyboard & mouse, in the remaining port that will sit between the external USB ports.
USB Ports
In this gap between the ports is where the wireless receiver will sit for the keyboard & mouse, the pair of screws securing the external ports in the centre have been shortened to make more room.
For convenience, a pair of USB ports have been fitted to the wearable Pi, which open on the bottom of the unit. These will be hardwired into a 4-port USB hub which will also support the wireless adaptor for the mini-keyboard that is to be used with the device.
USBs
The two USB ports on the bottom of the casing.
External Connections
The external connectors are also complete. The audio jack & second WiFi antenna port are fitted.
The audio is normally routed to the LCD display speaker, until a jack is plugged into the 3.5mm socket.
Here is an old chemical dosing system for industrial washing machines. These units are 4-pump models, with dual pumpheads. The motors are reversed to operate alternate pumps in the same head.
Label
From 2006, this is a fairly old unit, and made in the UK.
CPU Board
Main controller PCB, with interface to the power electronics via the ribbon cable, an external serial port for programming to it’s left. Powered by an ST microcontroller. The LCD is below this board.
PCU & Driver PCBs
Main power supply, sense input & motor driver boards. The PSU outputs +5v, +12v & +24v. The inputs on the lower left connect to the washing machine & trigger the pumps via the programming on the CPU. The motors are driven by L6202 H-Bridge drivers from ST.
Motor Assembly
Motor & gearbox assembly on the back of the pumphead. These are 24v DC units with 80RPM gearboxes.
UPDATE:
As it seems to be difficult to find, here is the user manual for this unit:
[download id=”5557″]
Here’s something new, an internet connected Geiger counter! The graph in the sidebar is updated once every 60 seconds, and can be clicked on for a larger version. Measurements are in Counts Per Minute, the graph logs 1 hour of data.
The counter itself is a Sparkfun Geiger counter, with the end cap removed from the tube so it can also detect alpha radiation.
Connected through USB, a Perl script queries the emulated serial port for the random 1 or 0 outputted by the counter when it detects a particle. The graph is pretty basic, but it gets the point across. Anybody who wishes to contribute to improve the graphing is welcome to comment!
As I’m building a portable “media center” with my first Pi, I was looking for a suitable screen. I remembered the existence of these:
ShowWX+ HDMI Pico Projector
A laser pico projector combined with a Pi, in a small enough package would make a fantastic
little portable media player. So £220 was shelled out 🙂
Along with the case for my Pi coming from Mod My Pi, I am aiming for a device as small as possible. At some point I will fit the Pi into the same package as the projector, if it can be cannibalised in such a way 🙂
Check back for an update with running images of the projector, powered from the Pi’s HDMI output.
I will also be doing the standard teardown of the projector when time allows 🙂
Bootnote:
Micro HDMI Connections: These are CRAP. They don’t stand up to any form of day-to-day use, and the projector began displaying a blue screen with “INVALID VIDEO MODE” as soon as anything was plugged into the Micro HDMI port. A quick attack with a jeweller’s screwdriver fixed the port, as it had become loose.
Here is an old electrochemical type carbon monoxide detector cell, from Monox. Hole in the centre is the inlet for the gas under test. DO NOT TRY THIS AT HOME! Electrochemical cells contain a substantial amount of sulphuric acid, strong enough to cause burns.
This is a type of fuel cell that instead of being designed to produce power, is designed to produce a current that is precisely related to the amount of the target gas (in this case carbon monoxide) in the atmosphere. Measurement of the current gives a measure of the concentration of carbon monoxide in the atmosphere. Essentially the electrochemical cell consists of a container, 2 electrodes, connection wires and an electrolyte – typically sulfuric acid. Carbon monoxide is oxidized at one electrode to carbon dioxide while oxygen is consumed at the other electrode. For carbon monoxide detection, the electrochemical cell has advantages over other technologies in that it has a highly accurate and linear output to carbon monoxide concentration, requires minimal power as it is operated at room temperature, and has a long lifetime (typically commercial available cells now have lifetimes of 5 years or greater). Until recently, the cost of these cells and concerns about their long term reliability had limited uptake of this technology in the marketplace, although these concerns are now largely overcome. This technology is now the dominant technology in USA and Europe.
Rear
Rear of unit with connection pins. Hole here is to let oxygen into the cell which permits the redox reaction to take place in the cell when CO is detected, producing a voltage on the output pins.
Disassembled
Cell disassembled. The semi-permeable membrane on the back cover can be seen here, to allow gas into the cell, but not the liquid electrolyte out. Cell with the electrodes is on the right, immersed in sulphuric acid.
Platinum Electrode
Closeup of the electrode structure. Polymer base with a precious metal coating.
Here is a Inductive charger designed for the Nintendo DSi. Cheap Chinese build, but it does work!
Overview
Top has been removed from the unit here. Most prominent in the centre is a solid steel bar, simply there to give the device some weight.
Pair of Tri-colour LEDs at the front indicates charging status.
Induction coil is on the left, with the controller & oscillator PCB at the top.
PCB Closeup
Closeup of the PCB, ICs have had their markings ground off.
Coil
Induction coil. This couples power into a coil built into a special battery, supplied with the base, to charge it when the DSi is placed on the dock.
Label
Information Label on the base.
Power Input
Standard DSi charger port, connects to the charger you get with the DSi. Power switch is on the right.
A quick update to my portable power pack, a mains charging port. Uses a universal DC barrel jack.
Connection to the battery. 1N4001 reverse protection diode under the blue heatshrink tubing. I used a surplus PC CD-ROM audio cable (grey lead). Seen here snaking behind the battery to the DC In Jack.
This is the internals of a motorised valve for central heating systems. Here the top is removed showing the motor & microswitch.
Left side of the valve, showing the gearing under the motor, & the valve body under the powerhead.
Right side of the valve, showing the sprung mechanism of the valve quadrant.
Here the motor has been removed from the powerhead, showing the microswitch & the sprung quadrant gear. This spring keeps the valve closed until the motor is energized. The motor remains energized to hold the valve open.
Here the valve body has been opened showing the internal components. The rubber valve rotates on the shaft, blocking the lower port of the valve when in operation.
The motor’s protective cap has been removed here showing the rotor. This is a synchronous motor, of a special type for use in motorised valves. As the windings need to be continuously energized to hold the valve open, it is designed not to burn out under this load. 240v AC 50Hz, 5RPM.
This is an old USB 1.1 hub that was recently retired from service on some servers. Top of the unit visible here.
Bottom Label
Bottom label shows that this is a model F5U021 hub, a rather old unit.
PCB Front
PCB is here removed from the casing, Indicator LEDs along the bottom edge of the board, power supply is on the left. Connectors on the top edge are external power, USB host, & the 4 USB outputs. Yellow devices are polyswitch fuses for the 500mA at 5v each port must supply.
USB Hub IC
This is the USB Hub Controller IC, which is a Texas Instruments TUSB2046B device. Power filter capacitors next to the USB ports are visible here also, along with 2 of the polyswitches.
Power Supply
The power supply section of the unit, which supplies regulated 5v to the ports, while supplying regulated 3.3v to the hub controller IC. Large TO-220 IC is the 5v regulator. Smaller IC just under the power selector switch is the 3.3v regulator for the hub IC. The switch selects between Host powered or external power for the hub.
This is the Current Cost CC128 Real Time Power Meter. Shown here is the display unit, British Gas issued these free to some customers.
This unit measures current power draw in Watts, cost of power currently being used (requires unit price to be set), overall kWh usage over the past 1, 7 or 30 days & power trends during the day, night & evening. Also displays current time & current room temperature.
Display PCB
Here the front panel of the display has been un-clipped. At the bottom are the RJ-45 serial port & power connections.
This unit uses a PIC micro-controller as it’s CPU (PIC18F85J90) Just above & left of the CPU is the 433MHz SPD radio receiver module. The chips on the right of the CPU are a 25LC128 SPI serial EEPROM for data storage & a 74HC4060 14 stage binary counter, to which is connected the 32kHz clock crystal. The red wire around the top of the display is the antenna for the radio receiver.
For more info on the CC128 in general, the serial port & software for computer data logging, see this link
See this link for Current Cost’s list of software
Processor & Radio
Closeup of the ICs on the mainboard.
Transmitter Unit
Here we have the transmitter unit, with Current Transformer (CT). The red clamp fits around one of the electric meter tails & read the current going to the various circuits. This unit is powered by 2x D cells, rated at a life of 7 years.
Transmitter PCB
The PCB inside the transmitter. Again very minimal design, unknown controller IC, 433MHz radio transmitter on right hand side with wire antenna. Two barrel connectors on left hand side of board allow connection of up to two more CT clamps for measurement of 3-phase power. Centre of board is unmarked header. (ICSP?)
Current Transformer
CT unit. Inside is a coil of wire & an iron core which surrounds the cable to be measured.
PIC18F85J90
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