What is technology inside gas station where you just put in credit card and fill the tank yourself. I has already taken a look at one Verifone payment terminal on what software it runs (it runs Linux). Today I got a view of what is technology used on similar device made by Dresser Wayne AB.

This is the device:

This it should look like

What I saw – I am pretty sure that device runs on some very old Windows version:

Application they seemed to be trying to start was IxPay. Booting up and starting of application took so long time that this incident resulted lost sales for this gas pump… I did not wait to see if it finally worked or not.

Type id if device:

Elisa Viihde is a IPTV service sold by Finnish telecom operator Elisa. The system works so that you have a set-top-box that connect to your cable TV and your Internet connection. You can use the set-top-box to view both live cable TV signal, your recorded TV programs from IPTV video recorder (in “cloud”), pay TV though IPTV and rent digital movies.

Elisa has used over the years several different set-top-box models. Netgem N7700 and N7800 are the newest model being used. They have new features, but have got some mixed reviews from users. Here is view what is inside Netgem N77000.

Here is view what is inside this old HASP software protection “dongle” that was designed to be plugged between PC Centronics printer port and printer. This is outdated technology because PCs have not had printer ports for many years.

Inside views:

Closeups shows that the main IC seems to be a custom made part for this (or at least custom marked).

Electrical motors need protection devices. EATON Moeller PKZM0-0.63 is a Motor Protective Circuit Breaker with manually actuated motor-protective circuit-breaker IEC/EN 60947-4-1, VDE 0660 part 102, rotating handle with clear switch position display ON and OFF. The current rating of this AC motor protection device can be adjusted from 0.4A to 0.63A. In addition to thermal overload protection there is quick short circuit release 8.8A. It is designed to be used with 220V to 690V three phase motors. At 220-240V this works with 90W motor power, and at higher voltages higher power. According to datasheet this can also be used DC circuits (AC-5 up to 250V) when three contacts are wired in series. The case is designed to be installed to DIN rail and has IP rating IP20

Typically a motor protection has two basic protections always installed for every motor: Over-load protection and Short-circuit protection. In addition to this, this device also promises some protection against unbalanced supply voltages (missing phase).

What is inside
To open I needed to remove stickers from both sides

Then there were small “clips” near corners that could be loosened quite easily with a small screwdriver.

The circuit from left to right are first after input contacts is bimetallic overload detection part followed with coils for short circuit current detection coils. After those are the main current contacts hidden somewhere…
It was interesting to measure around 5 ohms resistance on those bimetallic overload detectors – quite high resistance.

The complicated looking mechanism connected to bimetallic current sensing parts is designed to work so that it when all three phases are loaded with same current, it trips at rated current. When there is serious imbalance (different currents on different phases), the device works at lower current rating (so providing some protection on loss of phase situation).

Bimetalic when it heats up start to pull this mechanism made of plastic and something like what looks like “pertinax” circuit board material… When it moves to left, it releases the man contacts controlling switch back to OFF position.

Here you can see closeups of the heating wire wrapped over bimetallic strip and coils that are used to detect the short circuit current.

Links to more general information on motor protection:

https://www.schneider-electric.hu/documents/automation-and-control/asg-4-motor-starting-and-protection.pdf

https://www.l-3.com/private/ieee/Motor%20Protection%20Principles.pdf

Here is teardown of 10 A DIN rail mounted miniature circuit breaker (Biltema brand)

What you see when you open the case

Turn around – circuit open/off/tripped

Device reseted to “on” position

On the left side of mechanism there is bimetallic overcurrent triggering mechanism – load current goes through bimetallic strip and heats it. 

On the center there is solenoid coil for quick tripping on short circuit. 

Contacts that make and break the current are on right. On bottom there are stack of metal plates that take part in breaking the high short circuit current quickly.

Related posting with more background information: 

Circuit breakers for mains panel

Here is tear-down of old Zyxel  ES-108 10/100Mbit/s Ethernet switch. I had one on my network for many years, but one day it stopped worked and started making whining noise.

Look inside.

Closer look to details.

Main Ethernet switch chip is ADM6999 from ADMtek (now part of Infineon). In addition to it line transformers and power supply, not much more.

The problem seems to the power supply on board putting out wrong voltage to electronics: Varying from around 3.7V to 4V when it should be 3.3V. Chip heats up and nothing works. Maybe not worth to try to fix… get a new faster.

I today that someone had made a partial tear-down of street light lamp post.

So let’s take a look at wiring inside…

There is not much here, just some thick wiring, wire connection blocks and fuse holder.

I decided to replace my aging Zyxel and Netwjork 100 Mbit/s Ethernet switched with new gigabit models. I decided to get two ZyXEL GS-108S v2 Media Switch as replacement for those. The Zyxel GS-108S v2 10/100/1000 Mbps switch is designed to provide reliable high-performance media network connectivity – that’s what I need. The Zyxel GS-108S v2 8-Port Desktop Gigabit Ethernet Media Switch is advertised in the product page that it can easily connect multiple media devices to home networks at blazing-fast Gigabit simultaneously. Moreover, the newly designed GS-108S v2 allow smooth video streaming and online gaming activities. I think that “ allow smooth video streaming and online gaming” here is just marketing speak without any real meaning or added values – as any decent Ethernet which that works correctly should do those tasks well enough not to cause any issues. So this market speak does not make me to pay any more money for this or select this product over some other alternative.

Another feature that is somewhat interesting not wort of much money is somewhat reduced energy consumption – could in best case save a little bit electricity and make the switch runs less hot (so it might have longer service life). The GS-108S v2 can detect the length of connected Ethernet cables. The GS-108S v2 automatically detects power consumption according to the number of active connected network devices and cable length. With fewer active connected network devices or shorter Ethernet cable length, the switches will consume less power accordingly. Less power consumed with less devices connected has been pretty much standard stuff with any Ethernet switch for ages. The shorter the Ethernet cable length is, the less power it consumes, needs some new tricks.

It has two high priority, two med priority and four low priority ports.

Here is Application Diagram from product page illustrating how the Ethernet switch ports would be best used:

I think that in many applications today it does not matter much which port you use for which purpose. In case you are not loading your network anywhere near to 100% load, any port on the switch should theoretically provide pretty much ideal network performance for all parts. The priorities start to matter when the networks starts to get so fully loaded that some parts of it get congested, and at that time the priorities determine which ports get best service and which get somewhat degraded performance. Professional managed switches have for years have typically per port configuration for priorities and other properties (you need to know what you are doing to configure then correctly). This is a consumer switch, that should be easy to use, so assigning fixed priorities for different ports makes sense because makes switch easy to take to use (no configuration needed) and cheap (no separate processor needed on switch to handle web configuration interface) – and still provides priority support for those who need it (I think most users today don’t need that).

Here is look inside that gigabit Ethernet switch. There is not much to see here because most interesting main switch IC is below the heat-sink (that I do not want to remove risking damaging this brand new working switch.

Here is the power supply. It takes mains power and outputs 5V 1A for the electronics – theoretically you could replace it with USB power

At the moment both Ethernet switches have worked well – as any gigabit Ethernet switch.

Here is view what is inside logitech wireless optical mouse.

Let’s open it

When doing tear-down on this mouse I was hoping to find what was wrong on this broken mouse. I could not see any reason why it did not work anymore.

If you are wondering what is that component connected with wires to circuit board. It is the red LED of the optical mouse movement sensor.

Here is a look what in inside a broken Laserliner Active Finder Plus contactless voltage tester that is designed to detect

live lines from 24 V AC to 1000 V AC:

Not much see on this side of circuit board. All I can see is place for two 1.5V batteries, beeper and LED.

The other side has all the main components:

4069 CMOS inverter IC based circuit

The CD4069 hex CMOS inverter chip is quite classic circuit to build contactless AC voltage detection circuits. I did not trace all circuit on this one, but at quick look the circuit looks somewhat similar in the implementation to this circuit idea from From 100 IC circuits free book:

This circuit will also detects active mains at 15cm but has the advantage of producing a squeal so you can keep your eyes on the job. The mains must be active and will not work when the light-switch is turned off.

In this specific circuit several 4069 IC ic gates are used as an amplifiers and signal detectors. CMOS devices have large input impedance with input currents on the order of 0.01nA, which is quite ideal for a circuit that tries to pick up signals coupled from wire to circuit though very small capacitance through the air.

Links to other circuit ideas based on 4069 chip:

https://circuitdigest.com/electronic-circuits/broken-wire-detector

http://www.freesynopsis.com/2017/08/23/wireless-current-voltage-tester/

http://www.circuit-finder.com/categories/tools-and-measuring/conductivity-tester/738/invisible-broken-wire-detector

https://circuitdigest.com/electronic-circuits/broken-wire-detector

Button x10 sensitivity

LED Energie brand LED bulb with following data stopped to work properly:

230V 50Hz 7W E27

450lm 3000K 60mA 20D

3684 Mod.5161

So lets make a tear-down

Inside

There seems to be 20 small LEDs in series inside bulb and one of them burned black. As such this LED string is expected to need around 70V over it. LEDs were soldered to a aluminium circuit board thar was glued to aluminium tube inside plastic lamp base part.

Look at the circuit board

This looks like power supply is basically an RC current limiting (with small coil) followed by rectifier and small electrolytic filtering capacitor. In addition there are 470k bleder resistors to discharge capacitors.

The big resistor is a bit suspect here. According to color code it should be 100 ohms, but multimeter reading says 295 ohms. I suspect that either it has changed value or color code has changed colors due heating.

The RC circuit capacitor was 1.1uF 400V. The filter capacitor after rectifier was 2.2uF 400V electrolytic.

Here is the reverse-engineered circuit disgram:

I wanted to add an AC voltage meter to my electronics lab variac transformer output (0-275V AC). I decided to get a cheap Machifit AD16-22V 22mm Digital AC Voltmeter AC 20-500V Voltage Meter Gauge Digital Display Indicator with the following Specification:

It was was easy to install to a 22 mm hole:

In my testing the meter worked well and was accurate. The reading given by the meter was accurate against an accurate multimeter. I tested the measurement range from 20V to 275V AC. If the input voltage goes below 20V, the display on the meter becomes dim.

I did not do a tear-down of this device, because other people have done good tear-downs of similar meters. The following videos give a good idea what is inside this kind of meter:

Inside a 22mm digital panel indicator/voltmeter.

Voltmeter-indicator schematic and hydrogen pop.

Here is GE MT03M motor protector: Contactor, Miniature, Overload Relay, 5.5-8.0A Range

• Control circuit up to 690V
• Power circuit up to 690V
• Three-pole differential (phase unbalance protection)
• Automatic ambient temperature compensation between – 25ºC and + 60ºC
• Choice of manual or automatic reset
• Direct connection to contactor or independent mounting using accessories.
• Screw and Ring terminal versions
• Terminals protected against accidental contact in accordance with VDE 0106 T.100 and VBG4.
• Terminal numbering in accordance with EN 50005
• Degree of protection IP20 (EN 60529)
• Additional auxiliary contact block 1NO (with manual reset only)

This device is designed to be installed to a motor controlling contactor. It detects overload situation and then disconnects the coil control current from contactor which causes it to open the contacts – thus disconnecting motor from power source.

• Reset button, 2 positions : Manual(H) and Automatic(A) by turning the blue selector.
• Stop push button, independent of reset (red).

Look inside

Closeup

There are three bi-metallic strips that have heating wires around them. When the temperature gets high enough those bend to trip the device.

The complicated looking mechanism connected to bimetallic current sensing parts is designed to work so that it when all three phases are loaded with same current, it trips at rated current. When there is serious imbalance (different currents on different phases), the device works at lower current rating.

There are no opening contacts for the phase currents, because the contactor handles breaking the current if needed. The only contact on this device is the one that breaks or makes the contactor coil drive current (on the left side of the device).

Check also my other motor protector teardown.

Ankaro SAT switcher 9×12 for antenna and satellite IF signals

What is inside

The construction looks like the input signals go to some kind of RF diode switch matrix. There are control ICs and output amplifier.

Closeup

Is Samsung Galaxy S9+ the fanciest Android phone at the moment? Only teardown will tell if this phone is a true contender, or just a weird AR Emoji machine. Read Samsung Galaxy S9+ Teardown by iFixit: two blades for changing aperture versus the usual five on normal cameras; battery, iris scanner, front cam are basically unchanged from S8+

Check also Samsung Galaxy S9 Teardown

Here is teardown of one cheap car USB charger. It failed after few years of use.

Outside

Inside

Electronics

As you can see the fail was in soldering that connected two circuit boards. The fail had ripped of solder pads from circuit board.

The soldering quality on some other places also questionable.

There is simple swich mode power regulator built using AD85063S chip that has run quit hot. AD85063D Datasheet page has this circuit diagram that look quite close to what this adapter uses:

There were 1A and 2.1A outputs. They are connected to same power supply, the only difference between them was how data lines are terminated.

There are not any fuse in this circuit.

End result: not worth to repair. Replace with better one. According to one review it is a good idea to avoid this kind of AD85063 based adapter.

Here is view to an old surge protection terminal. Overvoltage gets directed through 1K5 surge protector to hopefully well grounded DIN rail this terminal is plugged to (component wire makes contact with metallic DIN rail).

Old Phoenix Contact terminals with gas tube based surge protection.

Helvar TS300 light dimmer is designed to dim incandescent light bulbs that are powered from 220-230V 50Hz AC power source. It is designed to be installed to wall in place of light switch. This is an old device that might not have been sold for ages. Once this type of dimmer was quite common on Finland.

What is inside

Closeup

This dimmer seems to have a thermal fuse to cut out power if the device gets too hot. The first picture shows the technical data available and the second picture shows the normal position this component is installed. It looks like this thermal fuse reacts if the internal temperature inside the dimmer case exceeds 115 degrees Celsius (239 Fahrenheit). It is a sensible safety device to have in addition to the fuse.

The circuit looks pretty typical for phase controlled triac based light dimmer. I did not trace all the circuit details, bit the main parts look pretty normal. It looks like this dimmer design is quite close to this other light dimmer circuit designed by the same Finnish company that I have documented in my Light dimmer circuits document.

The main difference are some component values and the fact that this smaller power dimmer has also thermal fuse in series with the mains fuse for extra protection.

Found this from eBay for about 2 dollars: New Mini Handy 2~150mA LED Tester Test Box for Light-emitting Diode Bulb Lamp

Description:

• 100% brand new and high quality
• Material: Plastic
• Color: White
• Handy device for testing LED’s. Simply plug your LED into the correct holes (all of which are marked) and push the button to see its brightness, illuminant color, etc.
• Handy device for testing LED’s (2-150mA)
• Simply plug your LED into the correct holes (all of which are marked) and push the button to test its brightness, illuminant color, etc
• The top row is for 2 pin LED’s with currents ranging from 2mA – 30mA
• The bottom row is for 4 pin LED’s (piranha LED’s) with currents ranging from 20mA – 150mA
• Lightweight & compact
• Powered by a 9V battery (not included)
• Item size(L*W*H) : Approx. 8 x 5.5 x 2.2cm / 3.15″ x 2.16″ x 0.87″
• Quantity: 1PC

Something wrong. LEDs get power at opposite polarity compared to what is printed to front panel. Let’s look what is inside.

Let’s look closer to the circuit. There seems to be one board with switch + LED + resistor. The other board contains a set of resistors that limit the current coming to the specified current. Because those are just resistors, the current will vary somewhat depending on the LED voltage (higher the LED voltage lower current it gets).

It seems that there is polarity mixup here. What start on power switch board as red wire from battery ends up being connected to black wire to LED test connector board.

Fixed

Now everything works as planned.