Experiment: Sylvania Lynx CFTE 42W Cool White Deluxe CFL Tubes

Every so-often, I drop into my local thrift shop because I just so happen to be passing by on another errand and have some time to spare. It’s often a good experience to sift through the random items for sale, and while the pricing is the least competitive it’s been in a long time, at least any money spent would be used in part for a good cause.

Among the things that catch my eye are the vintage electronics. This time, I came across a box of compact fluorescent tubes which were rather interesting to me. Priced at an attractive $5 for the box, I made the purchase and gave them a little more time before they reached their final destination (i.e. landfill).

A little CFL discussion and a Look at the Goods

At the moment, we are in the midst of a lighting revolution, and fluorescent tube lighting is on borrowed time. Regulations regarding energy efficiency are pursuing luminous efficacies unattainable with traditional fluorescent tubes, and hazardous material reduction legislation also looks unfavourably upon the mercury content within these tubes. As of last year, GE had already committed to shutting down its fluorescent tube manufacturing altogether. As a result, this is a timely find, especially when considering I did some reminiscing about fluorescent fixtures in an earlier post.

If you talk about compact fluorescent lamps (CFLs), the first thing that pops into most people’s minds (including the collective population of the internet) is that of the retrofit globes which screw/click into existing fittings, consisting of an electronic ballast and tube in a compact form.

But in reality, the term compact fluorescent lamp is broader than that. Technically speaking, the CFLs that are used in retrofit are better known as CFLi – the i standing for “integrated ballast/control gear”, but this term seems to have fallen out of popular usage. Instead, CFL merely means a fluorescent tube that is not in the traditional linear form, and is instead bent in a myriad of ways to reduce its size. Instead, now, such CFL tubes are often marketed as “Compact Fluorescent – Non Integrated” to avoid confusion.

The advent of CFLs were an important part of the history of the fluorescent lamp, as it made the high-efficiency technology more appealing to different use cases. This included higher power densities in smaller spaces to realize can-style downlights, as well as architectural “square” shapes enabled by 2D style tubes. In fact, there is a large array of CFL types and bases. The humble CFLi was a direct beneficiary of these developments, with some earlier CFLi bulbs carrying names such as PL (e.g. Philips PL) which reference the prismatic linear CFL tubes used to build them. I remember the earlier CFL bulbs also came in “separable” halves, where the electronic ballast had a PL base to accept a PL CFL tube and the standard Edison Screw/Bayonet Cap fixture at the other end to fit into a traditional fitting. Later bulbs integrated the two together for space savings, (likely) cost savings and reliability improvement (as the electronic ballasts had a limited lifetime as well).

While non-integrated CFLs have never been really popular in the majority of consumer fittings, they do see a certain amount of use in commercial fittings. I did see a good number of them even around the university I attended, it seems that the technology may still have a few years left. However, with the myriad of types, I suspect they will eventually be removed and replaced entirely as the tubes become harder to source and more costly, or the fittings begin to fail.

The tubes in question are Sylvania Lynx CFTE 42W 840 Long Life (278450LL) compact fluorescent tubes with a 4000K colour temperature, 3200 lumen output, 80-89 CRI and a GX24q-4 base. The luminous efficacy is about 76 lumens/watt, which is fairly impressive for fluorescent technology, but easily eclipsed by the best LEDs which reach 120-130lm/W. The units claim a 20,000 hour lifetime based on an 11 hours on/1 hour off cycle and are designed to be used on electronic ballasts only. The tubes are made in the UAE, although are an older tube, as presently available versions claim a 24,000 hour lifetime and use a blue base to distinguish the long life type.

The tubes use amalgam technology, where the mercury in the tube is made into a compound to regulate mercury vapour pressure and improve the high-temperature operating temperature characteristics of the tube, but as a consequence, the tubes have a significant warm-up time. This is necessary due to the high power density, as well as the significant bends in the tube.

The haul was a whole carton of 10, with a little water damage around the bottom, suggesting this was probably kept in a stock room somewhere and forgotten about. Then, possibly, the business closed and all the assets were sold, and this was part of the lot.

The reason I suspect this is because on the top of the package is a label for Mc Grath’s Hill Auctions, in Mulgrave. This suggests the whole package was probably auctioned, but didn’t find a bidder, and was then donated to the thrift shop by some commercial arrangement. Being in your average consumer thrift shop is probably one of the worst places for this sort of lamp – most consumers just wouldn’t have the fittings or know what to do with them! Eventually, after sitting on the shelf, it would have probably gone into the bin if it were not for me!

Each unit is packaged in its own colour cardboard box, in a mostly-green colour. The globe reaches a B-level efficiency in the EU’s energy efficiency scale. Its UPC is 9316236163701.

The EU energy efficiency scale and the icon with two dolphins on the front, suggests this globe is really not that old – possibly mid-2000’s by my reckoning. I suspect the dolphin logo is an indication of reduced mercury content, due to various requirements in different parts of the world with mercury doses reduced to no more than 5-6mg per tube.

The globe itself looks very similar to the picture on the box, featuring three interconnected U-shaped tubes in a delta shape, and a plastic base with four pin connections (to be suitable for electronic ballasts).

Markings are made on the body of the plastic base in blue print, with the ratings on one side, and the “LONG LIFE” indication marked on the opposite side. The rectangular base post has protrusions which allow for the socket to retain a “grip” on the lamp once seated.

The tubes are physically fairly long due to the 42W rating, so the tube seems to advertise a “crush protection” in the form of a silicone spacer which is pre-installed towards the end. This is in contrast to the consumer globes which often have glass hollows glued to the ends to maintain spacing, and may be a sign of high temperatures being a design issue.

Let there be Light? Maybe. Maybe not?

What good is having some tubes if we can’t make light with them? Well, rather sadly, these seem to have a base which wasn’t really that common, and generally speaking, a matching ballast is required to run them. Such fittings aren’t easy to come by at all. But there’s nothing wrong with a little improvising …

A while back, I salvaged a Vossloh Schwabe ELXe 236.523 T8/TC-L Electronic Ballast from the university and found it to be perfectly operational. Might this be a close enough match? Lets do some thinking.

The ballast is rated to supply:

  • 60w to 2 x 30w linear tubes
  • 64w to 2 x 36w linear tubes
  • 68w to 2 x 38w linear tubes
  • 62w to 2 x 36w bent tubes
  • 80w to 2 x 40w bent tubes

While it’s not got any rating for a 42W “bent” lamp, it seems to give the full 40W to a 40W TC-L tube, so it is at least capable of a similar power. Unlike some other ballasts, this one seems to have some tube-voltage dependent power delivery – notice only the 40W bent tubes get the full rated power delivery.

Doing a little more digging, it seems 40w TC-L tubes operate around 126V so have a current of around 317mA which is practically where we need it (i.e. 320mA). But the 42W CFTE is expected to have a higher operating voltage of about 131V. It’s a minor difference, which the ballast should be able to handle (after all, as tubes age, the voltage drop increases), but we need to test to see just how much power will be delivered.

Even though it claims not to be useable on inductive control-gear, trying it with a common 4-foot 36W choke could be unwise because it may regulate the current somewhere near the 430mA nominal current which is about 34% above the 320mA tube rating. This might reduce slightly because the operating voltage of 131V is higher than that of the 4-foot 36W tube which operates around 106V, but how the ballast might react depends on its design. If I crudely assume an inductive ballast to be a resistor, at 230V it has an effective impedance of ~288.372 ohms. Thus the calculated run current of the 42W tube on the ballast is about 343mA or a slight overdrive of 7.2% which it could probably handle. This is likely also to affect the performance of any power-factor compensation as well. I could probably try it … but then again, I don’t feel like needlessly modifying an existing fitting of mine with potential destruction of the tubes. The electronic ballast was “free”.

The reasoning behind not supporting inductive control-gear despite the four pin base is likely to be that the filaments aren’t particularly robust against a starter-based ignition which is more variable in the pre-heating of the filaments. They might be over-heated quicker due to their more compact size, or fail much sooner as they aren’t designed for frequent cycling as each starter-based start-up is like having 5-or-so on/off cycles on the lamp. But that’s really just a guess on my part. Some of the issues can be easily mitigated by swapping over to an electronic starter instead, but these aren’t that easy to obtain. One thing that’s for sure is that you won’t get as much brightness for the same energy input on an inductive ballast because of the gas re-ionization losses due to the low operating frequency resulting in more “dead time” where the tube is not conducting.

That being said, my choice of ballast isn’t particularly suitable either as the ballast appears to be an instant start type. The ballast chirps and starts the lamps quickly, with no noticeable pre-heating. The connection to one filament is just a single wire, suggesting it does not do any pre-heating current, thus it’s not a programmed-start unit with pre-heating that would be gentle on the filaments. It will shorten the life of the lamps, but I’m just happy if I get them to light even a few times.

No base? No problem. A few terminal blocks, a few random-coloured wires of mains rating or higher, a knife to cut off a little of the shroud, and judicious use of a screwdriver and the connection to the lamps is sorted.

As I had already wired the ballast up prior for test purposes, I thought I’d “bling” it up by adding an in-line switch to the cord, and give the input terminals some strain relief using a cable tie to grab the cable near the earthing eye. This particular ballast doesn’t seem to require an earthed reflector to start reliably according to the data I’ve been able to obtain – unlike some other rapid start ballasts.

The moment of truth was to flip the switch and see what happens.

The ballast chirped as it does, and the arc was struck successfully. The filament area can be seen to be slightly darkened, probably because of the harshness of instant starting them. The low brightness, including the complete lack of light from the areas away from the filament, is a normal behaviour for amalgam lamps.

After four or so minutes of operation, the brightness was even amongst the tubes and a lot of light was being produced. Rather alarmingly, the temperature around the filament area seemed quite hot, so I checked the power on the Tektronix PA1000 (which was in-line at all times to detect anomalous power usage) which indicated that the whole unit was consuming 83W, or just about the right amount. After three hours of continuous burn time, no failure occurred, although the IR thermometer was claiming the filament area was above 100 degrees C. This might not be unusual, given the high power density of the tube.

Not satisfied with just a few loose tubes and wires on a table, a small drill bit, a few bulldog clips, a few cable ties and an IKEA storage container later – I have something that’s a little neater.

Because of the random inspiration, I’m also in the process of grabbing a few electronic ballasts to add to my collection. Maybe I’ll end up converting one preheat fixture into an electronic programmed-start fixture just for the sake of it.

Bonus: My First Fluorescent Fixture

Since I did mention my first fluorescent fixture (which was a salvage) in a previous posting, but didn’t have the chance to show much of it, I’ll add it as a “bonus” part here.

This fitting was quite an old one, and it came with a Philips PowerMiser 18W T8 tube which was somewhat aged. Because I wanted an even older look, I actually went to Kmart and purchased a Mirabella branded T10 20W tube. At the time, the T10 tubes were actually pretty limited in number, so I thought I’d buy it because it was “special”.

I’m kind of glad that I did that, because the T10 tubes are even harder to come by nowadays. They really are visibly “fatter” than the energy saving T8’s that replaced them. They are less efficient, but the nostalgia gets the better of me. Nowadays, walking into one of the stores, it’s quite likely that you can’t even buy fluorescent tubes anymore.

It seems that the cost of the phosphor coating may be the reason why they didn’t coat the phosphor right to the ends of the tube. This particular tube has significant gaps in coverage at both ends which poses a slight risk in terms of increased UV emission from the tube. Rather interestingly, the light emission is influenced at the end by the filament position.

The fitting itself has an Atco EC20 20W inductive ballast, although the marking that says 600×38 suggests to me that it was probably designed for a T12 tube originally. I’ve never actually held or knowingly seen a T12 tube first-hand.

This is where the PFC capacitor that failed was. Because the neutral was looped into the PFC capacitor terminal and then onto the terminal block, I joined the ends of the wire with a small terminal block. The unit seems to be made by SUIV lighting industries, of which I cannot find a trace of anymore.

Conclusion

It’s amazing to think that I grew up watching the educational campaigns pushing home users to move from incandescent to fluorescent lighting, and now, we’re witnessing the death of fluorescent lighting in preference for LED technology. It feels sad to see it go, but as far as ‘fitness for purpose’ goes, the LED lights have many technical advantages which cannot be denied.

Despite this, having stumbled across a random batch of CFL tubes, I decided to save them from eventual scrappage and then improvise a system to get them to light successfully using a ballast that was not rated to drive the lamps in the first place. It did an acceptable job, although the instant start is hard on the filaments.

I also had a chance to show you what the insides of the first fluorescent fitting I salvaged looked like, and the T10 tube I purchased to go with it. Good memories.

Posted in Electronics, Lighting | Tagged , , , | Leave a comment

Repair: Click Surge-Protected & Sansai Switched 4-Outlet Powerboards

Powerboards are very simple and inexpensive devices used to convert one socket into multiple sockets on a (supposedly) temporary basis. Every house has a number of these devices, with basic devices simply bussing together the pins and more complex devices offering switching of outlets and/or surge protection.

Given that these items are so cheap, it might be wondered why I would even bother modifying or repairing such items which were never designed for repair. Ultimately, I take it as a challenge, but more importantly, fixing something saves you from buying something new and saves environmental resources as well.

Click Surge-Protected 4-Outlet Powerboard (CLKCPB104S)

Around the house, I’ve found a number of these boards doing duty. This is a fairly old Click branded product, and it turns out, there are a number of variations on it. This one has surge protection with an indicator LED on the board in-between the logo and the first socket. I also have another board with the LED just above the k in Click and without the moulded channels around each socket, which I suspect is a different design entirely.

The rear of the board shows it has the appropriate Australian approvals, and was Made in China. The “discard if supply cord is damaged” notice is likely to indicate that the unit is not designed for repair. The unit is held together by six security screws of the slotted-type with a post in the middle.

The cable and plug on it is intact and just fine, but what’s concerning was this burn mark on the top side of the board.

Generally speaking, most surge protected boards use metal oxide varistor (MOV) technology. This is frequently a blue disc-shaped component which drops its resistance sharply in response to voltages above a threshold, thus “crowbarring” or clipping the surge in amplitude. These tend to wear out over time, through exposure to accumulated surges, which can result in the voltage threshold of the MOV falling to the point where the device is conducting at the peaks of the normal mains voltage. This heats up the device, accelerating the failure of the device. Depending on the design, such devices can fail catastrophically and result in house fires. Understanding the internal implementation would be good to mitigate any risks.

Another interesting thing about surge protected boards is how the surge protection is implemented. Some boards have the ability to cut-off any connected loads when the surge protection fails, others have an annoying buzzer, while the cheapest just have one indicator neon or LED. A further design difference relates to the surge absorption capacity (related to the number and size of MOVs within the unit) and the type of protection offered (i.e. L-N only, or all three modes). I won’t be involved in an argument about which mode is best, although it does appear that three-mode protection does have potential issues of its own especially if the earth potential rises, whereas single-mode protection is likely to be quite sufficient in most cases, especially where double-insulated equipment is used.

As I’m planning an extended stay away from the home, I didn’t want to just keep using the unit without knowing what’s going on. As a result, the first step was to check the unit with power applied.

The unit reports its surge protection is still intact, after over a decade in service.

Connecting it to the power analyzer and a variac, it was determined that the draw of the unit varies between 0.67W at 220v up to 0.81W at 240v. At the extreme of the variac, I managed just shy of 1W. This doesn’t suggest the MOV is failing, although the power consumption is not trivial (in my opinion).

Consider that regulation exists that presently (in places, e.g. EU and certain states of the US) requires devices to have standby powers of 1W or less (depending on the function), and my own testing showed that some of the best phone chargers can manage idle powers of 0.01W – 0.1W, this adds up.

Lets say at 240V, the draw is 0.81342W. The yearly consumption will be 7.13kWh which means a cost of about AU$2 per surge protected strip just to sit plugged in and switched on. Lets say the average house might have six of these units, so AU$12 a year will be spent just keeping the indicator light on (in essence).

When I tried to get the waveform, there was some rather unexpected results – the current line was wavy (and the limited harmonic resolution of the analyzer didn’t help), and there was a phase shift as well. This suggests there is some capacitance (current leads the voltage) in the system.

Luckily for me, I had purchased a set of security bits a while back, just for this sort of occasion.

Looking inside, the unit is rather simple, with all the surge protection mounted on a short paper-type PCB above the plugs just near where the burn mark was. A second unit of the same design taken apart showed a PCB which bowed somewhat. The terminals are made of brass shaped into a “box” shape which provides good contact, and a circuit breaker is wired in series with the whole lot using crimp spade lugs.

The circuit breaker comes from Rong Feng RF-112B rated correctly for 10A/250V AC with line and load terminals correctly connected.

The unit features single L-N mode protection only, as witnessed by the parallel connection of the PCB across the live and neutral with no reference to earth. A single MOV is used, suggesting the surge absorbance capabilities is relatively limited. The MOV is protected by a nearby thermal fuse, rated at 130 degrees C. The input has EMI/spike suppression provided by an X2 safety capacitor rated at 0.1uF. Aside from this, the remaining components are used to drive the LED – half-wave rectified AC is passed through a resistor to the indicator LED. The resistor value cannot be ascertained reliably as the resistor is the culprit, causing heat that has damaged the colour banding and caused burn marks around it.

This board does not disconnect the load upon failure of the surge protection element. In fact, the surge protection element is practically self-contained, and relies on the tripping of the thermal fuse to indicate its failure. Should the MOV (and or capacitor) not be present or be open circuit, the circuit will still erroneously indicate the surge protection is available. No other fuse is provided, so this means that unless the MOV gets really hot or the draw of the PCB exceeds the 10A rating of the overload breaker, the board can sip current and get warm.

Seeing as the burn mark is only caused by the LED resistor, it’s probably fairly safe to reassemble the unit and continue using it with the expectation that the resistor will probably fail open at some future date, or the LED would otherwise go pop if it went short circuit. However, I wasn’t pleased with the standby draw of the unit and I felt that the surge protection offered was limited, I decided to remove the surge protection element entirely – converting the board to a non-surge protected board. I suppose it could be possible to eliminate the LED “circuit” to lose the indication while maintaining surge protection, only to have it become a fire risk later on, but as I’ve got ample surge protection all over the house, it really was not necessary. Many more modern switching supplies are fairly resilient to minor surges, and some even have their own integrated MOVs anyway.

This gave me a chance to examine the components of two of these boards which I have converted.

The safety X2 capacitors filtering EMI disturbances have a hard life, and with their “self healing” capabilities, they tend to degrade by a reduction in capacitance as areas of insulation damage result in the internal metal film electrodes burning away around the insulation. As a result, what should be 100nF registered just 73.39nF on one powerboard, and just 31.74nF on the other, as measured by an Agilent U1733C. The filtering would not be as effective as they degrade, and seems to be indicative of the amount of use these powerboards may have seen, especially near inductive loads which cause spikes.

The LED resistance is a bit of a mystery. One recovered resistor managed to read 41.44kohm, whereas the other just 37.02kohm (~11% difference). This suggests that the resistors have likely drifted in resistance as the tolerance was likely either 5% or 1% at manufacture, and is a result of accumulated heat damage.

Assuming the resistance of 37kohm, the approximate power dissipation on the resistor is V^2/R or 237.3^2/37k*2 = 0.76W. Note that I’ve multiplied the denominator by two as the unit will be operating half wave, and 237.3v comes from 240v – 2v for the LED – 0.7v for the diode. The resistor looks like a 1W or maybe 2W unit, so it’s operating pretty toasty especially considering such products often see 24/7 duty.

I was interested in the fact that there was draw on both halves of the mains – this seems to be mostly the capacitor current with the half wave LED current quite small in comparison to this. The diode did not fail, it was measured and exhibited a regular characteristic.

The MOVs were tested on the Keysight U1461A, and their 1mA breakdown voltages were 481 and 478.1V respectively. As the units are rated for 470V breakdown, these MOVs are actually still healthy, which was an unexpected surprise to me. Good to know, but too late now since I’ve chopped them out.

Sansai Switchable 4-Outlet Powerboard (PAD-054SW)

This is a low-cost powerboard sold at a local variety shop, but sadly, it hasn’t fared well with respect to time. It has a power indicator light, which serves no purpose really, as each of the power switches has its own internal neon to indicate power. The board has no surge protection – the indicator light may just serve to mislead.

Because it was purchased locally, it does also come with approval numbers and markings to allow it to be sold here. It uses the same type and number of security screws as the Click board above.

Amongst its defects is this switch which has entirely split across its front. If it continues to break, the switch could fall apart and expose live mains connections.

Another is the fact it seemingly over-drives the neon bulbs, resulting in rapid loss of brightness as a function of the amount of use a given socket has. It’s also got very low retention force in respect to the plugs inserted into the sockets – the contact area feels small and the plugs easily slide out at the lightest wiggle. I can’t fix that necessarily, but at least I can replace the duff switch!

Power consumption varies between about 0.3W with no switches on, to 1.3W with all the switches on. This indicates each neon and LED draws about 1/4W. The draw is in phase with the mains, so nothing unusual is happening in this powerboard. Interestingly, the consumption of the power LED is about 1/3rd of that of the Click board, which is more in-line which what I would expect.

Opening it up, we see that the unit is made with a bunch of solder connections, a PCB with a lot of wire and brass contacts. The incoming cable is physically restrained, and the circuit breaker is in series with the live. Earth goes straight into the busbar. The live is then run along the top trace of the PCB busbar, with a wire soldered at each switch-point to increase the current carrying capacity of the PCB (or reduce its resistance). The lower trace of the PCB is the neutral busbar, built in the same way, but using brown coloured cable. I suppose it’s no major issue, but it isn’t what I’d expect from a compliant product. The switches are soldered to the PCB directly, which is good as it avoids the possibility of the whole switch-cube being pried out of the front of the unit. Then the switched outputs are wired to the brass contacts which are crimp-terminated.

The switches (model HSK-1) claim to be rated at 10A, which is good to see as many aren’t correctly rated. However, I do have my doubts as to the contact life at that load.

Each of the brass contacts isn’t a nice brass-shaped “box” grabbing the pins as in the Click board. Instead, it’s just a single vertical piece with a slot cut out of it, which is designed to “rub” against the incoming pin along its edge. I don’t see much in the way of sustained springy-pressure against the pin, so a thicker pin can splay the single edge apart, meaning thinner plugs won’t have good contact. The small contact area, which is along the axis of insertion/removal, also results in low contact friction meaning that the plugs can easily slide out. A bad design if you ask me.

Repair involved getting the soldering iron out, desoldering the switch, cutting the insulation between the blades of the replacement switch, inserting it and soldering it in. Unfortunately, as the allocation of the “energized” and de-energized side of the replacement switch is the opposite, the switch rocks the opposite way to the rest of them. The neon also remains on regardless of whether the outlet is powered or not. Still better than a safety hazard, but in terms of power consumption, not the most optimal outcome.

Since the old switch isn’t of much use, I decided it’s probably nice to see what’s inside.

The construction seems pretty similar to the single-pole dual-throw wallplate switch with the exception that this is dual-pole, single throw, with a ball bearing at the end of the spring. As this is a dual pole switch, each pole is also connected to the neon and resistor combination at one side to act as the indicator. If wired with the mains coming in from one side, the indicator is off when the output is off, and on when the output is on. Otherwise, wiring with the mains coming in from the other side, the neon remains continually energized.

Owing to the limited rating of the resistor and the confinement inside the plastic, there was some discolouration of the plastic former which holds the neon. The resistor value appears to be brown-green-yellow or 150k, which seems a little low. Most neon bulbs strike around ~70-90v, so about 150-180V is dropped over the resistor, thus the current is conveniently 1mA or a little higher. The neon bulb would be operating at about 70-90mW, with the resistor dropping roughly 150-180mW of power. This is within the estimated 250mW rating of the resistor (although it could even be an 1/8th watt resistor due to its small size), but it means that it would be operating at relatively high temperatures.

It seems from this reference that normal glow is achieved from about 1uA through to 8mA. A regular NE2 designation bulb has a design current of 0.3mA with a lifetime of 6,000 hours. Running it at twice the design current cuts the life expectancy by eight-fold, so from that, it seems that the indicators in the switches are pushed quite hard and the neon is not expected to last even 750 hours.

There is a wide range of design currents for T2 miniature neon lamps with other designations, with currents ranging from 0.1mA through to 10mA, with generally longer lifetime (25,000h) achieved for the lower current models and shorter lifetime (1,000h) for the higher current models. However, significant variance is seen depending on the manufacturer’s design of the bulb.

Conclusion

Powerboards are pretty simple and cheap items, but that doesn’t mean they can’t be serviced, modified or repaired. It’s good sense to just avoid these things going to landfill if they don’t have to.

The Click unit’s burn mark was traced to a failing resistor that regulates the current to the surge protection indication LED, and not the MOV. The MOV is a single mode protection from L-N, with an EMI filter capacitor that has degraded in service. The MOV is protected by a 130 degree C thermal fuse, which is the primary means of failure protection and indication by breaking the circuit to the LED. The connected loads remain connected as the surge protection device is merely in parallel with the incoming mains. Due to the risk of future failure, and the needless use of power, the board was converted to a non-surge-protected board by removal of the surge protection element.

The Sansai board has pretty primitive contacts, and a broken switch which was desoldered and replaced. The switch was torn down, and the neon appeared to be driven quite hard, with the resistor causing some discolouration of the switch plastic. The indicator LED operated at much lower power compared to the Click unit, although the unit does not have any other “features” in regards to surge protection.

On the whole, the indicators-on-powerboards concept seems to be superfluous, and I dislike it in general, as it results in needless power wastage. In an era where many devices are forced to work below 0.5W-1W standby power, it seems silly to plug them into a power-board with an indicator or a switch for each socket that consumes 0.25-1W per position. While the burden is not big financially, it’s undoing all of the progress being made by the designers of mobile phone chargers, power supplies, etc. It’s also one of the reasons why many modern power supplies no longer have a power-on indicator LED, as the power consumed by that is significant compared to the unloaded power consumption of the supply.

Posted in Electronics | Tagged , , , , | 2 Comments

US Fax Test Services: HP, Brother and Canon

The death of voiceband modem communications is slowly but surely happening. I started Project Fax in recognition of this, as a way to remember one of the technologies, but sadly from the few faxes I have received, it seems I might be too late.

Regardless, we exist in an awkward period where there are still users of voiceband modem technologies, and somehow in an IP-centric world, we have to maintain backwards compatibility in a way that is somewhat reliable (enough) and hopefully not too costly.

To that end, fax diagnostic services are important for us to verify the proper functioning of our equipment. In Australia, Telstra operates FOLDS and FOLDS-B which provide technical information about the quality of your fax transmission. The only other commonly cited phone numbers are those in the USA, so I sought to try them out before they eventually go extinct.

Connectivity

As I reside in Australia, and I’m not travelling to the US anytime soon, I had to devise connectivity to the US to both fax the service and obtain the reply fax without having a physical land-line in my possession.

As a result, VoIP technology (i.e. not optimal for fax) was leveraged to perform this. All the test fax numbers are toll free and calls can be placed to these numbers through free online SIP toll free termination. The one I chose to use was Alcazar Networks, as they forward the CID as set and claim T.38 support. Note that calls in pass-through mode use G.711u in the USA as compared to G.711a in Australia, and setting the incorrect mode can result in call quality degradation due to transcoding.

The incoming line was provided by Callcentric, using their “free” inbound US DID program – the same number that is used for the US incoming line for Project Fax. Incoming calls are auto-answered by Digium Free Fax for Asterisk running on my FreePBX server, converted to PDF and e-mailed to me. This is a “virtual” fax machine to receive the faxes.

While I could place outgoing fax calls using the FreePBX server, I found the process to be problematic and unreliable. I tried using WinFax PRO under Windows 2000 Professional in a VM with a USB-to-Serial adapter with my Netcomm modem of choice, but it wasn’t operating properly today for some silly reason, so I resorted to an old Dell Latitude C600 laptop with Windows 2000 Professional and WinFax PRO using its internal mini-PCI 3com modem. In essence, a real physical computer to do the faxing. This was connected to the Grandstream HT802 ATA to convert the call to IP, sending it directly to Alcazar Networks by configuring it for “no-registration” operation.

To ensure the fax would be sent back to the correct number, the DID was programmed to the incoming Callcentric number, and the CSID was set in the US “domestic” 10-digit format – i.e. xxx-xxx-xxxx without the hyphens.

Hewlett Packard (1-888-HP-FAX-ME)

The most often cited number is this one, and you receive a return fax if your fax to them completes successfully. No technical information is provided about your call.

Brother (1-877-268-9575)

The next most often cited one is Brother’s test line. Again, no technical information is provided.

Canon (1-855-FX-CANON)

This number is operated by Canon, and I only recently discovered it. This one seems to send you back a fax that they have scanned rather crudely, but there is no technical information provided either.

Conclusion

I have managed to successfully, and without cost to myself, test and demonstrate the three toll-free test fax numbers in the US that I am aware of. The reply fax was successfully received and documented. Unfortunately, unlike the Australian services, none of the US services above provide any technical information or guidance as to the quality of your fax transmission – only providing an indication that your fax is successful with a reply even if the call was marginal.

Posted in Computing, Telecommunications | Tagged , , | Leave a comment