Crossy

http://www.powermatic.co.th/downloads/prod_dl.htm

click on TAP-Change AVR ....... what do you think of the spec..?

I would like to see a second boost stage but out in the boonies beggars can't be choosers, it should do the job quite adequately.

Input 220V +- 20%, so it's good down to about 176V input.

Lets assume that at 176V (-20%) the output will be at the lower specified limit (-7%) meaning that the output will be around 204V, thus we have a boost ratio of 1.16x.

Because it's a tap changer it should continue to work at maximum boost even if the input goes lower than that, at 160V input the output will be about 185V which should still keep your PC / UPS quite happy (much happer than it would be on 160V).

The big question, how much is it?

EDIT to correct calculations.

I can do a boarder run pay 20k plus a 5k fine and get my passport cleared

Where did you get this information?

A land based border run is most definately NOT RECOMMENDED when on even a short overstay. The buses are regularly stopped and offenders removed to the IDC. This will lead to a world of hurt, don't try it.

My neighbour wants to run a 60m cable from my modem to his laptop. I have a linksys wrt54gl router with 4 port switch running to my modem.If I connect him to one of this router / switch's ports will this do essentially the same job or do I need to purchase a separate 4 point switch and connect him up to that?

Yep, that should work just fine. Test it first with the cable length if you wish before you pull it, but there should be no issues.

Why not use the wireless since the router already has it?

Gentlemen, you are debating a fixation focused on maintaining "mains" voltages, where as the question was asking about PCs. As this has become a techie debate I am suprised I am the first to suggest the real cure (although beyond what many would consider worth doing) which is the build a lead-acid battery based PC power supply unit which gives reserve capacity for running the PC for hours (depending on battery size and PC usage). You would need two 12 volt batteries to provide the -12volt supply, floating earth. (Link for PC power requirements.) then simply trickle charge the lead acid using your dirty incoming mains supply.

There is little point using a 12 volt battery to step up to 220 volts just to step down to +/-12 5 and 3.3 volts again.

Ah. what about the monitor I hear you ask, many LCD monitors run from their own switch mode PSU so accept 12volt inputs already. Likewise with ADSL routers etc.

Actually you need to provide +12V +5V +3.3V and -12V to keep a modern PC running, if you look at your PSU you'll see the currents required, they are quite frightening, certainly outside the realms of simple linear regulators (gonna get VERY hot).

The simple solution which does not pose any risk of frying your PC with amateur electronics is a commercial UPS backed up by an AVR if you have wide mains fluctuations.

If you DO decide to go for a DC solution, it would probably be better to provide 300-320V DC to the mains side of the PC's PSU, you can then use the SMPS's regulation system.

I agree that it seems counter intuitive to jack 24V up to mains only to regulate it back down, in fact, if you look in large data centres with lots of servers, they all run off 48V DC from a system exactly as you describe, a bloody great lead-acid battery with a charging system (each server has an SMPS designed to take the 48V input an provide the internal voltages).

EDIT You CAN get regular sized PC PSUs that accept 48V DC like this on http://www.powerstream.com/DC-PC-48V.htm so the 48V solution is actually viable for an off-grid situation, it would certainly be more efficient.

Better yet, Powerstream also make regular ATX size PSU for both 12V and 24V input that would suit a solar/wind/micro-hydro off-grid system.

Given now that we believe a PC power supply should be able to cope with a bad waveform, what actual benefit would there be in spending more for an AVR rather than using an old-fashioned saturating transformer? OK, I can think of one; lower heat loss in the core, but is there anything else?

The 'saturation' or 'ferro-resonant' units don't cover such a wide range of input voltage, if you only have brownouts rather than dark-brownouts then I see no issues with using one.

Your UK license is legal as you're a tourist.

Actually it's not, you need an IDP to be fully legal, as do US citizens (guess from the spelling of 'license').

BUT

If you're hiring from a big name company (Hertz rather than Somchai Rentals) they will have cover that pays even if you're not totally legal, the hire companies only ever seem to look at your national licence when you take the vehicle.

As think_too_mut suggests, the smaller hires come with zero insurance, all at your own risk.

The police almost never ask for an IDP, to be honest most wouldn't know what one looked like, your UK licence will work just fine at normal traffic stops/checkpoints.

For the 5.50 that an IDP costs, it really is a wise investment, just to be sure.

Can't confirm for definate, but I heard something very similar when I suggested putting a carryboy on our 4 door pickup, apparently it would move the vehicle up the tax list to be an SUV

In the end we didn't put the cover on so I can't confirm the validity of this

I may be stating the obvious, but since 167v is getting into the realms of a "dark brown" brown-out, it would be important to check the AVR spec to make sure it can cope with a voltage that low, or whatever the lowest you've ever measured actually is. I'm not sure if they all go that low.

Good point, they don't, that's why I used the word 'good'.

The one that I linked to (dunno if it's available here but I'm sure something similar is) is good down to 150V, I assume it will simply stay on maximum boost if the supply continues to fall until eventually the output drops below the UPS threshold and it kicks in.

EDIT The one referenced is a tap-switching unit, I have no idea how the ferro-resonant (cheap) units behave as the input falls outside their operating range.

If you are OK with your PC losing power (just want to protect against voltage variation), the SMPS internal to it is going to be just fine. There are ways to provide battery backup to the 12V rails to make things work through an outage, but it doesn't always work just right, so you get stuck with a UPS.

One major plus using the AVR is that it will keep your UPS batteries well charged for when you actually do lose power. The better ones will keep the output at 220V even if the input is down near 150V, I seriously doubt that a PC power supply running near its max output (aren't they all) is going to hold up at that input level.

I remember those 'internal' UPS's from some years back, are they still available considering the increasing number of supply rails and currents being used?

Did the mods spike my reply from yesterday ?

I lost a post here yesterday as well .. glad to know that I'm not going crazy.

Perhaps you could both re-post your responses, any and all ACCURATE information is most welcome

Posts don't normally get deleted unless offensive, and there's usually a mod. note included in the thread, maybe technical issues.

Well ive looked around our local electrical shops explained what I’m looking for and got a blank stare back, so its off to a bigger Town for another look , just one thing have I got this right, to day my house mains voltage went down to 167 Volts for about 15 minuets and my UPS sounded the alarm so I shut down the computer , If I were to have a AVR plugged into a house mains socket outlet and then take my USP power feed from the output on the AVR , when my house voltage fall again to 167 Volts , the AVR will compensate for the low voltage and supply the UPS with 220Volts ..?, if saying my house voltage drops to 167 Volts and stays at this voltage for a longer period , say 2 Hours , do you think an AVR would supply the UPS with the correct 220 Volts for this length of time..?

Keep persevering, they're out there to be found.

If you use a unit as I showed earlier, then it will boost your low voltage forever! Because it acts as a variable transformer it simply pulls a greater current from the (low) input so that the input power (VxA) is the same as the output power (less a little for inefficiency).

Feed your UPS with this regulated supply and it should only go on battery if the mains actually goes off

Probably wise to get her to write it or get it off her id card. You've already got two spellings and my luck would be to choose the wrong one

If you have a visa of any type you should have no problems with a one way ticket

If you do NOT have a visa (or an onward ticket within 30 days) there is a strong possibility that you will not be permitted to board your flight to Thailand.

Many of the bigger wheels have low profile tires. It all depends on the circumference of the tires. Larger diameter rims with low profile tires have the same circumference as original equipment tires so there is absolutely no difference. If the circumference is larger the odometer will read less kilometers and the kilometers per liter will be less but will actually will be the same. Depending on the engine and original gearing you may get better fuel economy. Most pickups are geared for power so a larger circumference wheel can actually improve the kilometers per liter.

True Gary

I was assuming that our OP intended fitting off road tyres on a vehicle which currently doesn't have them.

We really need to know exactly what he intends doing and why, back to you intumult

If you fit off-road tyres you'll lose mileage and gain road noise.

Depends upon your usage, unless you're doing a lot of off-road then stick with HT (Highway Terrain) or AT (All Terrain) class tyres for a reasonable compromise. These tyres normally fit on the standard (15") rims and fit in the arches without modifying the suspension.

If you put the big, wide mud tyres (and raise the suspension to clear) then expect even more road noise and even worse mileage.

We have Bridgestone AT tyres on our Ranger 4x4, it manages 30-33 mpg and we've never got stuck even in the wifes 'short cut' via the corner of a rice paddy (saves about 5km)

We bought new (Ford Ranger 4x4) about 18 months ago.

No discount on the list price, but we did get a bed liner, bug deflectors, roo (buffalo?) bars and window tint (although we paid extra for 3M film) thrown in along with 12 months 1st class insurance.

Obviously, YMMV

My favourite route is to miss the capital altogether by using this route:

Leave K'buri and head east on ??? there's a turning not far away that leads to Don Tum, from Don Tum you go to Lad Lum Keaw, and direct into pathumthani or round the western ringroad to the Saraburi road. From there its a simple straight line along the eastern ringroad to the new airport.

For at least the first 60% of the trip the roads are only single carriageway so be careful especially if driving at night

Yep, gotta be the best, 324 out of K'buri then the 346 to Pathum.

Once you get to Pathum you can get on the outer ring (route 9 IIRC) and go all the way around to the expressway east of BKK or cut the corner by going through Rangsit (traffic) and join the 9 heading south.

K'buri - Pathum is a bit variable, there's a lot of widening work going on and some bits are single lane but generally a fast'ish road.

No, but using a proxy connection is.

Then surely the powers that be who spend vast amounts of resources to constantly monitor the internet for anything naughty should block www.propel.com, I very much doubt the average user of this service would even know what a proxy connection is. As the Thai government feels they know best what we should and shouldn't be accessing then I propose that it is up to them to extend their protection of the innocent and ensure that unwitting customers do not subscribe to a service that would be breaking Thai law

Careful, the powers that be read this site.

Actually, I don't think using a proxy is illegal, only using a proxy to bypass the government block.

Not sure how they intend enforcing that, I note that many of the proxy reference sites are blocked though.

I don't think an actual date has been set as yet. according to a mate 'in the know' april-may is favourite.

International driving permit is valid for year but maybe limited to 3 months,you need to check this 1st.

You can drive on them until they expire and or apply thai drivers licence when you got settlment visa and do thai test

Isn't that what I said in post #4?

Actually it's 90 days not 3 months, which resets whenever you leave the country.

There is no such thing as a 'settlement visa' for Thailand (many of us wish there was) you need a non-immigrant visa of any class to apply for a Thai licence. If you have a current IDP you don't need to do the driving or theory tests, you do still need to do the colour blindness, depth perception and reaction tests.

I will have to scout about in my Local IT mall , Just wondering if any other forum members have

see one of these type of units about any where..?

Amorn is THE major supplier of electronic bits n bobs in Thailand, there are several shops around, the biggest being the Old Siam Plaza in Ban Mo (BKK).

You'll probably score better looking in electrical outlets as these things see wider duty than just IT, very good for keeping your air-con going (and prolonging its life) and stopping the lights flickering all the time.

Zeer Rangsit is worth a look if you're in northern BKK.

Where are you located?

Just found this ...

at ...... http://www.shop4thai.com/en/product/?pid=12622

Not too sure if this is what's being talked about ..?

Sort of, but it has batteres possibly a bit OTT since you already have a UPS.

The things I'm thinking of are in just about any Mom and Pop electrical shop, and are considerably cheaper, Amorn certainly have them and I think I've seen them in HomePro too

EDIT Something like this http://www.line-conditioner.com/SLc-600-12...Conditioner.htm

Is there any thing I can do to help this situation with my UPS clicking away

All day..? can I buy a larger / better type of unit , would this help at all..?

Depends on what you want to accomplish.

If the UPS is shutting down the PC too much for too long, a larger higher power unit might be able to run on the battery for a longer period and thus not need to shut you down. Also, if your UPS cannot handle lows you see of 124vrms, then a better rated unit would be able to run with that low an input.

I doubt you'll get much help from the local electric company, but it is worth a try if you have the time.

Agreed Paul.

I'd go for a two-pronged approach. You have two issues to address:-

1. Low voltage for prolonged periods
   
2. Power interuptions
   

Atack 1. with a good quality AVR (Automatic Voltage Regulator) which will take your low input and boost it to 220V, they do this without batteries, in effect they are a variable transformer which automatically adjusts the ratio to give a pretty constant 220V. Feed this into your UPS which can then concentrate on its primary function of bridging over actual power failures, point 2.

Once the UPS has a nice solid 220V you may find that it is adequately sized for your application. You MAY be able to install additional batteries to increase the run time, depends upon the UPS itself, cheapies tend not to have this facility.

Did the mods spike my reply from yesterday ?

The dc power source which runs the high frequecy oscillator which drives the switches and thus the ferrite in a SMPS is NOT itself a SMPS. So unless it has been well overdesigned, a 20 percent dip in the line will probably take it out in exactly the same manner as a linear PS.

The UPS is your protection from line dips and brownouts. If it is not well designed as above, then the battery is going to being working hard. I assume there is hysterysis at the switching point so it is not repeatedly clicking in and out.

Hmmm, didn't see any reply previously, and I doubt the mods would have removed it unless offensive

Agree 100% with the above, -20% is the bottom end of reliable operation (about 180V on a 220V supply) at that level you'll have almost no protection from skipped cycles. A 'universal' (100-250V) PSU would be far better as they're good to about 80V input.

If you have chronic under-voltage a simple UPS will run its batteries down as they don't normally have the line-boost function that you see in the expensive on-line units and will therefore go on battery too often for the (low) supply to re-charge properly. A simple AVR transformer will boost your line to 220V, use that to feed the UPS which will filter the crap out that the AVR puts in and give you proper brown/black out protection and you're in business

I don't have an AVR, our mains is pretty good voltage wise and I have a (bloody expensive) on-line UPS that's good down to 100v input (apparently, never tried it).

I looked at a Z71 Chevy Colorado that had a lockup rear differential. I don't know if it was available with Isuzu.

Yeah, I remember they were also offering the locker on the 4x2 as a get-you-out-of-the-mud option that cost less than the 4x4.