Shunt Resistor to measure current (In Swedish)

Count on using a copper cable as a resistor shuntUse Googe Translate, This is written in Swedish.

Räkna på kopparkabel som shunt.

Nu är koppar ganska temperaturberoende så det finns så klart bättre material att använda (t ex legering av konstantan, manganin eller kanthal A-1), men man taver vad man haver.

Vi behöver en antingen en motståndstabell eller så räknar vi fram en lämplig längd och resistans.

Själv tycker jag det är smidigt att använda jämna siffor, dvs 1 millivolt motsvarar 1 ampere och därför anpassa motståndet därefter.

Ställ multimetern på minsta voltmätning, ofta 400 mV.

Om du använder exemelvis en resistans på 1 milliOhm så fås när du kopplar in multimetern över shuntkabeln ut att tex 0,1 mV är lika med 0,1 ampere (vid en viss temperatur, ex 20 grader C).

Tittar man i olika tabellsamlingar så hittar jag t ex tre olika resistivitet angivna.

Följande tre resistivitetvärden hittade jag:

0,0167 ( ohm x mm^2 x (1/m) vid 20 grader Celsius ) //Tabeller och formler för NV- och TE-programmen, tryckt 2002//

0,0172 vid 20 grader Celsius //äldre fysik och formelbok som en kollega på jobbet hade//

0,01745 vid 1 meters längd och en area av 1 mm2 vid 15 grader Celsius. //Karlebo//

Det var i alla fall samma Temperaturkoefficient ( 1/K )

4,3 x 10^-3 = 0,0043

För att räkna fram resistans i en trådlängd finns följande formel:

Resistans= resistivitet x ( trådlängd/genomskärningsarea )

Anta att vi vill räkna fram en resistans på 1mOhm ( = 0,001 Ohm )och vill få fram rätt trådlängd, Låt oss räkna på en temperatur på 20 grader Celsius så kan vi ta tabellvärdena rakt av och slippa räkna på temperaturkoeffcienten. Jag vill använda en 16 kvadramillimeterskabel.

0,001 = 0,0167 x ( Obekant/16 mm^2 )

è Obekant = (0,001x16)/0,0167 vilket om man räknar ut det blir 0,95808383233532934131736526946108 meter

Dvs. jag ska ha en kopparkabel som är  ca 96 cm lång och där ledningsarean är 16 mm^2

Hur påverkas då resistiviteten av temperaturen, låt oss räkna lite igen

Då finns en formel som låter som mäter resistivitetens temperaturberoende:

Nya Resistiviteten = resistivitetvidbörjan,dvs i vårt fall 20 grader x ( 1 + (Temperaturkoefficient x temperaturskillnad))

Anta att vi vill veta vad resistiviteten blir vid 15 grader, dvs. en minskning av temperaturen och därmed kommer resistansen att MINSKA, dvs. ström går lättare igenom kabeln.

Nya resistiviteten = 0,0167 x ( 1 +(0,0043x-5grader C) )

0,0167 – (0,0167x0,0043x5) à 0,0167 - 0,00035905 = 0,01634095

Så nu har vi en ny resistivitet som vi kan räkna med, den som gäller vid 15 grader celsius.

Låt oss se vad vi får för Resistans genom vår ca 96 cm långa kopparkabel på 16 mm^2.

Resistans= resistivitet x ( trådlängd/genomskärningsarea ) à

Resistans = 0,01634095 x ( 0,958 / 16 ) = 0,00097841438125 Ohm

Vilket alltså är nästan 1 milliOhm (0,98 mOhm ). Som vi ser har temperaturen en rätt stor betydelse.

Jag testar med att räkna på 0 gradigt väder också.

Nya resistiviteten = 0,0167 x ( 1 +(0,0043x-20grader C) )

0,0167 – (0,0167x0,0043x20) à 0,0167 - 0,0014362= 0,0152638

Då räknar vi på samma kabelstump  på ca 96 cm igen, nu alltså vid 0 gradig temperatur:

Resistans = 0,0152638 x ( 0,958 / 16 ) = 0,000913920025 Ohm

Oj, nu är vi nere i 0,91 milliOhm.

Vad har då detta för praktisk betydelse, låt oss ta ett exempel på dessa tre temperaturer. Och låt oss räkna på att det går en likström på 100 ampere som går genom våran strömshunt.

Ohm lag: U = R x I à 0,001 x 100 = 0,1 volt dvs. 100 millivolt.

Så våran kopparkabel fungerar =) Vid 20 grader Celsius så kommer vi få ett spänningsfall på 100 millivolt.

Allt perfekt alltså. Som ni kommer ihåg så var tanken att 1 millivolt skulle representera 1 ampere, dvs 100 millivolt lika med 100 ampere.

Vid 15 grader: U = R x I = 0,00097841438125 x 100 = 97,84 millivolt vilket allstå ger ett felaktigt utslag på 2,16 ampere..  om man tolkar 1 millivolt som 1 ampere.

Vid 0 grader: U = R x I = 0,000913920025 x 100 = 91,39 millivolt vilket allstå ger ett felaktigt utslag på över 8 ampere.. Det går alltså mer ström än man tror i kabeln (om man tolkar 1 millivolt som 1 ampere).

Thoughts about storage and bed frame

I belive in the KISS principle (Keep It Simple Stupid). Simplicity is Genius sometimes. Instead of using 2x4 woodframes, I will try to use storage compartments to make the base of the bed.

One of my role models is Laren Corie,

Laren uses a couple of big Walmart trunks, for his bed foundation. He then uses plywood which is only 1/8" luan. I think he lays this plywood on his trunks. On top of this I think he uses an air madress. He sleeps diagonal in the back of his AstroSafari van.
The size of his trunks are 42"x18"x13", thats equivalen to 105x45x32,5cm

So I started to look for some trunks also: This is what I found at Jula:



249 kr. Picture from Jula: http://www.jula.se/stor-plastback-108-l-781898

  Max loading capacity: 70 kg. Volyme: 108 l.
Length: 600 mm
Width: 500 mm
Height: 390 mm


Cover for the trunk above: 99 kr. Picture from Jula


Other KISS storage: I have seen a lot of Vandwellers usting something like this:


349 kr from Jula: http://www.jula.se/forvaringsskap-med-plastlador-460004

Width:  380 mm 
Height:  800 mm 
Depth:  430 mm 

Cotton VS Wool VS Synthetic (Polyester, Fleece and so on)

Now when its getting colder, avoid using cotton clothes when sleeping
Cotton sucks moisture from your breath and body and will get damped with moisture when humidity gets in your van. Low temperature also increases the relative humidity
Cold weather underwear (I think you call them that, in Sweden we call it “underställ”) often have a base of polyester or polypropylene. These materials absorb very little moisture and thus keeps the body dry and warm. A basematerial of wool has in recent years been increasing its market share. The wool absorb although moisture, but it heats (unlike for example cotton) even when damp. Furthermore wool underwear almost never smell bad and feels comfortable to wear even for extended periods of time without washing. A polyester underwear will pick up smell more than wool.
Keeping warm when sleeping:
Fleece Sleeping Bag Liners

Wool Blankets (ullfilt) (the inner core of wool fibers absorbs moisture (as much as 36% of its weight))
, long johns (underställ) and wool socks.


Other alternative:
Build a isolated triangle to lay in, use some cardboard for the “small triangle house” and dress it with insulation boards on the inside.

Here is an example with some pictures:
http://www.practicalsurvivor.com/urbansheltercoldweather

On the Road Stuff that can be useful, Shower and emergency blanket

Here in my country Sweden there is no Walmart that has just about anything. But we still can find some useful stuff, and here are a few:


Emergency blanket (Nödfilt värmefolie in swedish)
Insted of using reflectix (which I still havent found cheap here), less expensive,
easier to store, no seams to leak heat. Put a mylar emergency blanket between
it and your sleeping bag if you want to add "reflectix".

This emergency blanket is of dimension: 2,1x1,3 meter. Try putting your sleeping bag in this blankett. Or use as an isulation for the windown on a hot summerday, reflecting the sun radiation.

This blankett cost 29 swedish crones, and is available at the Jula shop:


mylar emergency blanket to keep you warn when it´s cold outside your car
Picture from: http://www.jula.se/nodfilt-varmefolie-956122




Picture from: http://www.jula.se/nodfilt-varmefolie-956122




Camping shower
This cost 69 swedish crones.
Put it on your car roof under a warm summerday and you get some nice warm water to take a shower in later. If you want you can save the bag, put it in a isolated bag inside the car, and get heat during the night when sleeping. This bag is easy to store, when not using it. (instead of a black plastic container)


5 gallons or 20 liter pvc-bag (so dont drink the water)
Picture from http://www.jula.se/campingdusch-20-l-759003




Simple camp shower, hanging from the tree
Picture from: http://www.jula.se/campingdusch-20-l-759003



Summer Road Trip 2012: Yngsjö havsbad in the evening

Before going to the next town Kivik, I stopped at Yngsjö Havsbad to have a look. I always like beaches, trying to find beutiful spots. This was a Nice beach with pure sand. If I remeber correctly this was close to a camping.

Took a photo, Beachtime in the evening.

On the road between Åhus and Kivik I went passed Yngsjö Havsbad, and had to stop to se what the place looked like

DIY Heat Exchanger ventilation, save on energy

I found this Do It Yourself instruction on the Internet and thought I share it. Why? Heat Recovery Ventilators helps you keep the air varmer and saves on your energy.

So here it is, a nice DIY Heat Exchanger project from Charles Platt:

http://makeprojects.com/Project/Heat+Exchanger/279/1#.UKo0XmfRZ8H

Also featured in Remake America: http://www.make-digital.com/make/vol18/


Värmeväxlar ventilation (in swedish)

Keeping food cool. Refridgerator with extra insulation

I think this is a perfect solution. A small chest fridge box (running on 12 volt) with some extra insulation material and then some straps.

Use som polyisocyanurate to put your fridge box on. And on the sides.




Refridgerator with extra insulation Chest box Waeco Dometic
Picture from Excellent site by Bob Wells:
http://cheapgreenrvliving.com/Converted_Cargo_Trailer.html



Living small, the Bufalino concept

This is the Bufalino concept, folds down the driver's seat to provide a sleeping berth.

Always fun to find new ideas! =)

Keeping warm in the cold, some tips and information about furnaces

Here are a few tips, when the nights get cold. I have only travelled in the summer, but here in Sweden it can bite quite cold even then. :)
Use a isolating bed to sleep on. During some road trips I sometimes use an airmadress to sleep on. It takes minimal space.

wearing extra clothes to bed to stay warm. BUT, they
should NOT be cotton. Cotton holds water and makes you colder--synthetic only in
the cold. A got tips is heavy wool or synthetic boot socks for your feet (dry ones!). Fleece is for example a good material, and not so expensive. Microfleece is incredibly warm.

If your car is unisolated like mine is there is a tip for cold weather and sleeping, place the clothes you are going to wear the next day under your blankets so you can get them warm before you put them on.

Isolation: Cover your sides in the car / van by hanging ThermoReflex / Reflectix or a Space Blanket over the entire door or window. Tha can make a difference also (if you seal your place of, keep some air coming in somewhere so you can breath. Measure the oxygen level (instrument) to be shure. Use small magnets to hold the ThermoReflex in place, taping the magnes in place.

In my next car I will probably get a heater (solid fuel heater, marine) that I can use charcoal and wood for. Either I build my own from a propan gas bottle (P11) or end up getting something like this that I found on the Internet:



Picture from: http://www.go2marine.com/product/20010F/newport-solid-fuel-heater-00-newsf.html?utm_campaign=googleshopping&utm_medium=productfeed&utm_source=googlebase&WT.mc_id=gb1

Non-rust stainless steel construction

Heat output 3000-8000 BTU

However, I would have prefered the possibility to warm water, or do some food on the Stove, so probably have to build my own.

Probably use a straight pipe, 3 inch flue. no bends, so it is easy to keep clean (i know, missing som of the heat radiation. Probably harder with bends it you cant diassemble it..

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Another alternative is this furnace:




Boat furnace, Image from: http://www.gaiamarine.dk/ovn.htm

 Size: H: 370 x B: 240 x D: 240mm. Pris i about 4000 danish crones.
 It´s a danish guy who makes this, read more here: http://www.gaiamarine.dk


Another option I found is this wood stove:

Smålandsspisen in "child" size, fully functional. Its is a small copy of the real Smålandsspis (Småland Stove):

Width: 360 mm
Deepth: 300 mm
Height: 290 mm
Weight: 27 kg
Smokepipe diameter: 56 mm

The swedish price is about 5250 swedish crones. Aproximately 800 american dollars (in todays value)


Picture from: http://www.bastuspecialisten.se/art/zoom/sm%C3%A5landsspisen-barn/SSBM

This was originally called: "Husqvarna no 2" during  late1800, but it is remaid and now called "Smålandsspisen no 2".



This is the original from about year 1920. Husqvarna no 2
Picture from: https://www.stadsauktion.se/1110/107029-barnspis-husqvarna-no-2/
(Sold for 1200 swedish crone in an auction)

Other sites, 

Diesel Heater: Glembring, A swedish firm in Gothenburg: http://glembring.se/kaminer/

Installed on a boat by "Perra" from Oxelösund. This is pretty much a copy of the Danish Refleks stove.




Glembring Diesel Heater in a boat, picture from user "Perra" from Oxelösund http://forum.hamnen.se/attachments/seglar-snack/12201d1237821609-vedkamin-i-bat-2008-09-29-12-19-33_0001_resize.jpg

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Photos from Jesper H.

Looks like a painted Refleks..

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Refleks 66M, This is what I bought.
This furnace has an outer shell that protects so it wont get red and you can have it pretty close to other stuff. Just use a stainless steel sheet or whatever to protect.

Took a trip south of Norrtälje to buy this Refleks 66M. I haven´t tested it yet though.

The Kimberly Woodstove is good looking!
"A Mini Wood Stove Engineered For Smaller & Bigger Spaces When Close Clearances Are Required…"

Screenshot from there homepage:
https://www.unforgettablefirellc.com/kimberly-wood-stove/?fbclid=IwAR0pRqjPd2_1Vh1Q4h6JCcPHP2LgDt9MnlIsh8DOgandQVkdAm8YdkjPstc

Stoves made out of rolled plate steel are tough, highly resistant to damage and is weldable, so if you wish to add some featers Steel is the way to go. However, often the steel stove looks ugglier.
Wood stove from vedkaminer aktiebolag (A swedish company): http://www.vedkaminer.nu/kaminernew.htm

Kamin UGGLAN

Kamin LAXEN I
Lenght: 47cm
Width: 30cm
Height: 41cm (legs 22cm)
Weight: About 15 kilo
Smokepipe diamenter: 10cm

Price for this: 1681 kr
Picture from: http://www.vedkaminer.nu/kaminernew.htm

Laxen without cooking plate, unfortunatly no separate air intake.

Stove Öringen:
Solid Cast iron instead of steal, looks better, more thermal mass
Lenght: 40 cm.
Height: 41 cm, (legs 20 cm. )
Width: 31 cm.
Weight: ca 23 kg




Stove Öringen, price 2588 kr:
Solid Cast iron instead of steal, looks better, more thermal mass

Tiny Tot: http://www.fatscostoves.com/

Nice mini stove in this van. I think it's a Cubic Cub Wood stove.

 Cubic Cub wood stove, https://www.youtube.com/watch?v=x3bBPCvoaf4

Cubic Mini Wood Stove

Isolerande väv som dom isolerar fönster och taklucka med. Verkar bra!

Winter in a van - Vanlife Finland

https://www.youtube.com/watch?v=WJ25SqBKZYM
Ser ut att vara samma friskvattentank som Jula säljer. 10 Liter med tappkran


It was 1,4 metre wide fabric and it costed 14 euros per metre. :) 7 layers total.

Photo from Chris A

Photo from Izzy F.
Nice build!

Cubic Mini Wood Stove

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A pretty big stove.

Photo from Josefine E.

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It’s Cubic Mini Stove from Canada
Less than 2 kW tror Vantastic, 1,6-1,8 kW.

Tiny wood stove install to campervan

https://www.youtube.com/watch?v=f2yzkCgORDw&lc=z22dwxw41sqmifuuvacdp435lrh5io4nswytotvkh2hw03c010c.1518623754112290

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Some smaller furnaces
Trolla
Norrahammar nr299 tex


Norrahammar 48



---- Liten kamin för värmeljus ----------
https://www.netauktion.se/auktion/produkt/liten-kamin-for-varmeljus

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Wood stove in Tarifa:


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Volkswagen T4 -2000
Vedkamin (woodstove), 100 cm bed..

Small little woodstove in a Volkswagen T4.

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Photo from Jeremy

"My van is parked for the winter & not moving with the stove in it ever." - Jeremy
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Emergency setup. Dangerous.. Cant recommend this!!
 clay pot. And clay tray
Dont splash water on it.. "the stress from rapid cooling will cause it to severely crack and sometimes shatter!!"