This page is dedicated to the internals of machines and equipment. Don't expect to see the pistions of a steam
engine here. With 'machines' I mean electronic machines. Mainly.
The first thing I do with new equipment is to open them up. You never know: there might be a screw loose and
then you need to fix it before it falls into an open cap!
And when looking at the insides, I take a few snapshots. For reference only. Have a ball looking at the
insides of my machines.
This was the Sweex ADSL modem I bought when I thought I wanted to get connected to Internet via a subscriber
line. It failed due to the ISP who didn't want to deliver. So now I'm on cable and sold the Modem/Router to a
Same view, only now with the bonnet up. In the front, you see a stack of LED's (my fingers are itching not to
'recover' them immediately) in 5 x 3 formation. For the rest, this machine consists of very few integrated
circuits and many many more capacitors.
Apparently, you need to be a capacitor maker to make profit nowadays.. :o)
This picture is for the freaks among us and it shows the brand and type of the ethernet controller. See the
deer's head? Some people think this is a lobster, but man, are they wrong!
Anyway, the deer shows that this is an RTL chip. An RTL8305 to be precise. The SB after the type are the
initials from the guy I bought this modem from. Apparently he is a big shot within RTL.
According to a friend who borrowed this modem for a week, it was identical to the E-tech modem he had (well,
that week he didn't have it since it was being serviced).
Earlier this year I realized an old wish: a double power outlet outside my house (in the front, on the
pavement) so that I could run my power tools without long extension cords.
But I needed to run it safe, so I decided to connect the outside outlets via a special plug to an indoor power
The plug is special. It is a Brennenstuhl earth leak protector. It trips when there is more than 30 mA of
difference between live and neutral and if the current exceeds 16 A. And if I push the 'Test' button.
No shots of the insides yet. :o(
On the right, you see my first digital multimeter (DMM) which I bought in 1980 at Piet Kennis in Tilburg. It
was not particularly cheap, but it was a Fluke and in those days that meant:
Add it all up, and the NLG 450 (EUR 200) 1980 price tag was not that high. You still pay a similar amount for
a good DMM nowadays.
- Extremely robust. Drop it off a table and it still works.
- Accurate, due to the double slope integration.
- Complete: DMM, manual, probes, quickref card, soft vinyl carrying case.
All ranges protected. Plug it in the mains while in the 'Ohms' range and nothing is damaged in the meter. It
just says 'Overflow'.
- Battery operated, with a long battery life
- LCD panel instead of LED's
- It measures conductivty in the 200 nS (nanoSiemens) range.
The only problem with the machine was the LCD. It turned slowly black after a few years of use. I applied the
heater trick, the freezer trick but in the end, the LCD remained unreadable.
So in 1995 I ordered a new display in the US. SInce then, it has worked as it did before.
The Fluke 8020A does have a few disadvantages, compared to modern DMM's:
On the other hand, it also has some clear advantages over the 'competition':
- Small 13 mm display (my other DMM's have 20 mm or more)
- No bargraph
- Not autoranging
All in all, I am very fond of my Fluke 8020A. It was made in my the town I live in now, so that ought to make
me a bit proud as well.
- Very constant
- Very reliable; even with a depleted battery there are no errors
- Lots of functions and ranges
I bought the 'Finest 3487 DMM' via mailorder in the United States around 1994. It is a fine multimeter. Fully
autoranging, with lots of goodies. It has only one drawback: it doesn't allow changing function. If I am
measuring Ohms and want to switch to measuring Volts, I first have to turn the dial to the 'Off' position.
But apart from that, this is a very nice and versatile machine:
In february 2005 I discovered an anomaly of this machine: it can be a bit unreliable. I was measuring NTC
resistance as a function of temperature and I did see the BAT indicator blink occasionally. Since it wasn't on
all the times, I assumed the battery wasn't fully depleted yet.
- Nice, big digits
- Good dial
- Low energy demands
- Nice colour: easy to spot on the workbench!
- Serial interface included
The other day, I was working on the Lithium cell of my AP400 computer and when measuring the voltages of the
old cell and a fresh one, I noticed that there was a difference between readings when I swapped the testleads.
So the reading with 'right' polarity was +2.916 Volts, whereas the reading was -2.869 with the opposite
polarity of testleads. When measuring a depleted NiCd 9 Volt block the results were +7.52 and -7.02 Volts.
Quite a difference. And the actual voltage of that cell was 7.27 Volts.
After I renewed the battery (the LOW BAT indicator was not on yet), the problems were gone and now the Finest
reads the same value as the Fluke.
I bought the Peaktech around 1999 from Reichelt in Germany. The first one I got there refused to do anything.
It didn't even show a single digit on screen.
So I sent it back and promptly got another one. I was not smart enough to write down the serial number of the
one I RMA'de, so I don't know if the 'fixed' it or if I got a brandnew one.
Not that it mattered, in the beginning. The 3380 DMM was a very nice multimeter. It performed very well on all
functions and ranges. OK, the beeper, used in continuity checks, was very low in volume, but I used the Finest
for this anyway.
But some months ago, small errors popped up. And now I have severe troubles in the functions:
When in these functions, the meter effectively powers down. When I turn the dial to a 'supported' function, it
clearly resets itself since the display momentarily shows all segments and indicators.
I guess surgery will be needed.
This is how the inside looks like. It took some boldness to split the two shell halves. Near the RS 232
connector are some hidden retainers and you need to apply gentle brute force to open it all up.
Well, I succeeded. And this is what it looks like. The DMM is nicely shielded with lots of conducting foils
and a lot of energy was spent on craming it all in this little space.
Now you can lift the green PCB up (after removing the screws, of course) to find that the LCD is fixed in
Here we see the topside of the PCB that comprises the meter. On this we see, from right to left:
And this is where it hurts. The area to the right of the blue electrolytic capacitor has some kind of whitish
precipitation on it.
- Four shielded banana style receptacles
- Bottomside of the function-dial
- The POWER switch (black square, right under
- The hole for passing through the main retainer screw for the shell halves
- The beeper
- A lot of electronics
- A bank of capacitors in the bottom left corner
I checked the elco's but none of them seems to have leaked or exploded. So there must be another origin for
this compound. I think the malfunctioning of the meter is (at least partly) to blame on this substance.
On the left, you see my favorite NIC (Network Interface Card). I buy these at Reichelt in Germany. Don't know
about a local source, but they would most most probably be too expensve for the same product.
Anyway: this is a very fine NIC. It is recognized by all Linuxes I know off without further ado. It's
faultless. It's german quality. And that says it all.
The Longshine NIC uses the RTL 8139 chip (the one with the deer on top of it) as can be seen in the rightmost
Here you see my favorite Ethernet switch: the Longshine LCS 883R SW800M+. It has all you need, and more. I
also have an SMC switch, but it cannot even stand in the shadow of this Longshine. I name just a few of the
Below you see the backpanel of the switch.
- Complies to IEEE 802.3 (10 Mbps) and IEEE 802.3u (100 Mbps)
- All 8 RJ-45 ports are for all speeds
- Supports NWay protocol for speed and duplex mode auto detection
- Supports MDI/MDI-X auto crossover
- Full and half duplex operation on all ports
- Supports back pressure and flow control according to IEEE 802.3x
- Wire-speed packet filtering and forwarding rate
- 'Store and forward' architecture filters fragments and CRC error packets
- Supports 8192 MAC address entries in whole network
- 92 KB (768 kilobit) buffer memory
- 17 LED's for power and network diagnostics
- External power adapter supplies 12 Volts @ 0.5 Ampere
Of course, the lid can be removed. There are two screws that anyone can see. The other two screws are under
the front rubber feet. Don't force it open with just two screws removed.
On the left, you see a switching power supply, which is the reason why the Longshine switch performs so good
with respect to power usage. My SMC switch demands 1.5 Amp at 7 Volts, so that's 10 Watts and this Longshine
eats less than 6 Watts. And it outperforms the SMC.
In the center is the deer-like Ethernet switch. In the bottom is the octet of RJ-45 connectors. And in the top
are two rows of SMD LED's for status information.
And here is the hearth of the machine: the RTL 8309S8 Ethernet switch controller chip. This black piece of
plastic with a deer's head on it, does it all.
Some people claim the picture on the RTL chip is a crab. But I prefer to see a deer's head.
Above, you see another detail: the optic conductor that guides the light from the SMD LED's to the frontpanel.
It's easy, but it does the job. No need to use elevated LED's. Just conduct the light. Great job, guys!
To the left, you see one of my Longshine switches in active duty. It buffers the signal as it enters the house
(my modem is in another room outside the house).
- the modem cable is plugged into port 1
- one cable goes to the SMC switch which is used on the third floor
- one cable goes to the second floor
- one cable goes to my dungeon where another Longshine 8 port switch is located.
I could have used a 5 port buffer switch here. Actually, the SMC is 5 ports and it used to be in this place,
but it consumed too much power there so the PSU got too hot. So I wanted a Longshine switch there as well. The
price difference between a 5 port and an 8 port switch is so small, that for the one or two euro extra, I
prefer to have the 8 port switches. Some spare sockets are always a good idea.
The switch is mounted to a vertical piece of timberwood. Above the switch is a round aluminium shield to
enable warm air to escape through the venting holes, but to prevent dust from falling in the same sleeves.
To the left, you see the Longshine switch that I use in my dungeon to supply this wonderful internet medium to
all of my computers.
Near the back of the switch is a spoke from a bicycle wheel that I bent a bit. The mounting holes in this and
most other switches and routers assume that you mount the device horizontal. But then you either have good
access to the connectors, or you can well see the status light. And I wanted both.
So I mounted the switch vertically. But then the weight of the cables tends to pull the switch downwards... So
I came up with the bent spoke and two woodscrews.
You can use any kind of available metal, but a good quality spoke (double butted and stainless steel if
possible) is very rigid. And it's shiny.
The blue thingy near the top is a piece of heatshrink tubing to protect the top of the case of the switch from
scratches by the spoke.
This Longshine has been in use now for several years and it never has been reset for malfunctioning. A sign of
good engineering if you ask me.
To the right, you see my power supply. It's getting old, but it's just what the doctor ordered. It's a
Handykit model HPS 3025. Here are some of the features:
The hole on the top right is not for ventilation. It's there because I ripped out the original voltage control
potentiometer. It got noisy and especially the lower voltages could not be set anymore.
- 0 - 30 Volts DC output, 2.5 A max
- Adjustable current limiting
- Indicator for overload
- LCD for actual voltage (100 mV resolution) on the left
- LCD for actual current (10 mA resolution) on the right
- Independant +12 Volt output (0,8 A)
- Independant +5 Volt output (0,8 A)
- Strong and compact metal case with good ventilation openings
- Intelligent transformer control
So I came up with the small TEKO box, mounted on top of the case. In it is a 10 turn potentiometer of 50 K.
There was no room to mount such a big potmeter inside the casing, so I needed the bulge method. With this
setup, I can control the voltage very well between REAL zero volts and slightly over 30 volts.
Sometimes I dream about making my own, digital controlled power supply with lots of outputs, but then I think:
Why bother, if this is all I need.
I run my small tools (like my miniature drill) off this power supply and it's very assuring to know that the
current limit is very accurate and reliable. It kicks in when the motor overheats or gets into a stall. This
machine was a good buy. Thanks to the guys of Piet Kennis in Tilburg.
On the right, you see the frontpanel of my Cybex SwitchView KVM switch. It is a 4 port switch to connect 4
PC's to one set of
devices. It saves a lot of resources:
and it allows you to control several machines from place in the room. The SwitchView requires three cables to
connect to the KVM peripherals:
- Desktop space
Each PC is connected to the KVM switch by a set of cables:
- Plug the male connector of the VGA screen in the Master VGA slot
- Plug the male connector of the PS/2 mouse in the Master Mouse slot
- Plug the male connector of the keyboard in the Master Keyboard slot
The Switchview is powered by the keyboards that are connected to the system. Diodes protect against shorts
between the several PC's.
- one PS/2 cable (with 2 male connectors) for the keyboard,
- a high grade VGA cable with male connectors on both ends
a choice of cables for the mouse:
The SwitchView will take care of translating between the attached PS/2 mouse and computers who think they
are using a serial mouse.
- one PS/2 male/male cable for a PS/2 mouse
- one 9 pin serial male/female cable for a serial mouse
Each connected PC is signaled by two LED's. The green LED tells that the respective computer is powered up.
The amber LED shows which computer currently has the KVM peripherals connected. All other computers assume
that they have them as well, but that's the trick the SwitchView plays upon them.
On the right, you see a cheap serial mouse that I took apart. This is a special mouse. It's easily blinded....
Sometimes, this mouse accumulates debris on the interruptor axes. So I need to take out the ball of the mouse.
Easy, just unscrew the plate in the bottom of the mouse and shake the ball out.
But when I point my flashlight inside the mouse to see where the debris is located, it gets blinded in one or
two directions. I need to remove the mouse driver from memory and reload it with the respective commands
Then it has lost the memory of the torch and it works again.
As you can see, inside this mouse is plain old nothing. This is an empty mouse. Or close to it, anyway.
But it works and that's what counts.
In the picture you see:
The two black shafts are driven by the mouse-ball. The mouse ball has a diameter of 22 mm. The shaft is 4 mm.
So this is a factor 5.5 speedup gear. Combine this with the 80(?) holes is the photo interruptor on the end of
the black shaft, and you get 400 interruptions for every 60 mm the mouse travelled.
- The base of the mouse (top)
- The handheld part with the buttons (bottom)
- The mouse's ball
- The mechanical part of the mouse, which is in the base
To the right you see my auto-present: a 14.4 Volt Makita 6228DWE cordless screwdriver/drill. It's a powerfull
machine and it was on sale at the
Hornbach DIY shop
a few miles away from here. The price difference between this machine at Hornbach and a shop around the corner
was over EUR 70!
The 6228 DWE came in a sturdy plastic case, with one reversible screwbit, a spare 14.4 V/1.3 Ah battery and a
Model 1414 rapid charger (30 minutes for a 1.3 Ah battery). For the time being, I will only use one battery. I
will start using the second one when the current battery is worn out.
On the left, you see the battery charger. It looks simple, and that's just how a charger should look like.
There's a battery bay for accepting the shaft of the batterypack. And there is a LED. As it looks, this is a
duo colour LED, which can signal several messages which are all listed on the front of the charger.
Here is what the LED's will signal:
- Blinking green: mains power OK
- Continuous red: battery is being charged
- Continuous green: battery is charged
- Blinking red: system is too hot
- Red/Green blinking: battery is depleted. Discard now.
On the right we see the same charger, but then with it's clothes off. If you want to replicate this, do as
But as usual: you do this on your own risk. You're a big boy now, so if you foul up, you clean up the mess as
- Remove the four screws in the bottom
- Do NOT lift the cyan coloured top!
- Place the charger with the black part on the table
- Put your index finger inside the battery bay and press down
- Now gently lift the cyan coloured cover up
As you can see, inside is a well designed switch mode powersupply, built with fine quality parts, as we might
expect from a Japanese product.
Take a look at the place where the duo colour LED is supposed to be... There isn't one in sight.
What we see here, is a typical piece of japanese engineering. Instead of a doubly coloured LED, there are TWO
rectangular single colour LED's, which are glued together, thus mimmicking a two colour LED, but with an
easier driver interface. But it works, and that's what counts.
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