Ive got all the parts to make a 2 variac fan controller, similar to Rastajedi's & Danlads


heres some pics of the parts


the replacement enclosure box after i Lost the other one
it measures 13 7/8" long, 8" wide & 6" high.

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Maplins 0.7A variac, its only got 2 screws holding the dial on unlike Rasta's & danlads which has 3 screws.
ill use the dial to mark the holes ill drill out.

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for the thermometer, im using a honeywell T6360.

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& instead of using the wired in adaptor extensions, i got these from bnq.

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ive also got the 5A relay & holder to control both the variacs at once with the one thermostat.
model no N13AW with the 8 pin socket DIN.

(din means it's mounted on din rail, the other type has pin coming out the bottom
to be mounted onto a circuit board)

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e2a -- does anyone know what the 2 prongs are for ? me & danlaad havent a clue

for connector block, i got some 15A, which might be a bit overkill but it'll do.
it cost about £1.50.

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& once ive wired everything together, ill use self adhesive cable tie mounts & cable ties to keep everything tidy,
think they cost just over a quid from bnq.

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as for the cable, i got some 1.5mm 3 core, think it was a tenner for 10m.

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& not forgetting the 4 cable glands, they cost about 3 quid for the lot.

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i havent bothered using an inline fuse but ill put a 3A fuse in the mains plug &
ill use a 20mm flat wood drill bit to cut out the holes for the glands.

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now just have to copy danlads wiring diagram without electrocuting myself

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if anyones going to attempt to build their own variac thermostat controller, please be carefull as BurstBud says

use a ip56 rated box... coz these suckers CAN KILL...

so whats the total cost mucka and have you got it all rigged up buddy

gonny put it together tomorrow nite as i need to get the 6" rvk sound sorted before running it,
its like a bloody turbo jet being in the same room that & the 6" x 600mm CF

plus i need to get the plants moved into the tent pronto, theyre starting to outgrow the cab,
& ive already had to top the mazars a bit as they were starting to suffer


ill post a cost tally but i think its around the ton mark

Click to view attachment Finally managed to spare some time tonite & i took some pics whilst i was at it.


this is how i started out.

a weather proof box, a drill, 4 cable glands & a 20mm flat wood drill bit.

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these pics are of the base of the lid, i decided to drill 1 hole on the lid for the thermostat cable
& 3 holes on the box's base (1 for power in & the other 2 for power to the 2 fans)
i also fitted the glands, theyre very easy to fit & you can tighten them up with your fingers.

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the next thing to do is to mark the holes needed on the box lid for the variacs.
so place the variac on the lid & you get a rough idea of where you want to fit it.

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i unscrewed the knob & dial from the variac & used the dial as a template to mark with a pencil.
i used a 7mm bit for the main hole & a 5mm bit for the 2 screw holes.

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this is the variac fitted & set to 50% power.

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this is the 2 variacs fitted, theyre not that big

oh, a wee tip to remember, before you take the dial & the knob off, move the knobs indicator to 0 power
& check the position of the arm on the back of the variac, this way you wont put the knob back on at the wrong power setting

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the next installment will be in the next few days & ill be attempting to wire it all up together

Thanks for the great guide so far, looking forward to the rest.

Can you say where you got the enclosure? I've been looking for a suitable one for a while.

thanks Gwaan

i got the box off fleabay, £15 & thats with p&p included.

ill start the wiring tomorrow & ill post the results,

Hello JH, great to see another variac build, thought it best to point out that variacs can get pretty toasty with long term use and you might want to remove the paper label thats stuck to the underside of the lid, in time the glue could dry out and the label start drooping directly onto the variacs, its probably odds against it happening but rather safe than sorry n'all that
Have fun and best of luck with the rest of the build mate doing a great job so far, enjoy quiet non-buzzing automated fan control

Rj

thanks for the tip Rasta ma man


i went to start the wiring last night but im bloody hopeless at soldering ended chucking it ater a few failed attempts.
im just going to go to maplins before work & pick up some lucas female connectors to try instead.

Does this box control the voltage? I can see it's a fan speed controller I assume this is basically what my airforce speed controller is (Which was £140 for the 2amp version) looks pretty cool, I would have a go as I do like a bit of DIY but parts cost wise I think I might as well buy the 3amp version instead.

Am I right in thinking the cheapo fan controller control the amps which causes the wine (Like dimmer switches)


Thanks

QUOTE

Does this box control the voltage ?
I can see it's a fan speed controller I assume this is basically what my airforce speed controller is

i think its basically the same, its just a cheaper diy version with an added in room thermostat,
so, you can set the stat at say 30c & if the room goes above 30c, the variac kicks in at
full power until the temps drop below 30c then itll return to the lower voltage/speed.

QUOTE

I would have a go as I do like a bit of DIY but parts cost wise
I think I might as well buy the 3amp version instead.

it all depends on cost at the end of the day but reckon i could make a similar controller like
yours (airforce) for between £61 for the 0.75A & £71 for the 2.75A controllers.
could possibly do them cheaper if i used an old pc psu's enclosure box.

the IP66 ABS plastic enclosure costs £10.
the Variac is a 0.75A £34 (p&p inc) or a 2.75A for £44 (p&p included)

if you want a seperate spare socket to plug anything in (240v)
then you'd need 3 20mm glands £2.64 (88p each)
1 Socket Garden Lead 10m £9.50
1 socket extension head £4.00
1 15A connector block £1.00




anyway, back to the ongoing variac build,
im still a bit stuck on soldering the wires to the variacs but ive been
watching some you tube clips to try & get the hang of it.

does anyone know if i could use female spade connectors instead ?

cheers
JH

i hope so as thats what i used crimped on nice n tight and should be fine

yes, ya dancer thanks Promethius


the only thing holding me up now is i need to get some 8mm spade connectors,
on the maplin 0.75A variac, terminals 1, 2 & 4 are 6mm & terminal 3 is 8mm



its always something

hey jh,

looking good so far. anyway i used spade connectors to connect to the variacs, not going anywhere so should be fine, i hope so anyway

still no luck on the prongs?

dan

funny enough Dan, i did

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ah yeah ,

wonder where mine are now?

so its just to hold it in place then?


ya got it wired up yet?


dan

Hi Dan

yep, they just hold the relay in place !
clever buggers like Rasta & Scraglor musta thought we were a right pair of thick cunts

right, ive done most of the wiring after a lot of fuckin about with spade terminals
& should hopefully have it all finished tomorrow night

just need to work out how to wire the thermostat, cant remember if you use 3 or 4 core

Wow a ton ya could buy one for little more than that an save a lot of fucking around Click to view attachment these are only 14quid more than you paid to make yours

know what your saying Leppy but the primair makes the 6" rvk hum.

plus its been really interesting in making my own controller compared to buying something of the shelf.

Nice work JHS. I'll be having a go at one of these as I'm using a Primair and the 6" fan I've got on it buzzes loudly unless it is on full power.

Like you say, should be fun too!

They control fan speed through amperage which causes a hum from the fans, these variacs (And my airforce controller's) control them through voltage which doesn't.

I do have one of those controllers never used it more than 5 minutes £80 down the swannee at the time I bought my airforce one the next day.

The hum can be very loud and I may be wrong but I think a dimmer switch (£3 wilkos) wired inline would give the same quality controller albeit without temp sensing.

sorry for the delay in getting this finished, i had some problems with the wiring but i think ive got most of it sussed.


heres what ive done so far.

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finally got my finger out & managed to get my head around wiring the variac
& please ignore the above diagram, its wrong

heres Danlads Diagram slightly modified, i followed his plan but the variacs were wired wrong,
we just had to switch the neutral on 1 & live on 2 around, ie N on 2 & L on 1

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this really helped, so thanks to Dan & Scraglor & Rastajedi for all their help

heres a plan of how i finally did it.

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& heres what i used & the cost of everything.

weatherbox 210mm wide - 150mm height - 350mm length £15.00 (fleabay, p&p inc)
2 Maplins 0.75A variac variable transformer (part no GL42V) £31.14 each + £2.99 P&p or £54.86 for 2 + free p&p
relay - 'Min 5A DPDT 240Vac (part no N13AW) £3.54 (maplins)
relay holder - 8Pin Rly Skt DIN (part no N36AW) £1.98 (maplins)
1 pk10 Lucas 6.3 female spade connectors £1.00 (maplins)
1 pk10 Lucas spade covers £1.00 (maplins)
3 inline fuse holders (part no RC71N) £1.69 X 3 = £5.07 (maplins)
1 pk10 1A quick blow fuses. (part no GL74R) £1.69. (maplins)

honeywell T6360 thermostat £9.00 (fleabay, p&p inc)

15A connector block £1.50 BNQ
4 black 20mm grommit glands £3.52 BNQ
1 pk20 self adhesive cable tie mounts £1.50 BNQ
1 pk500 cable ties £ 1.00 BNQ
2 single trailing single sockets £3.70 each - £7.40 for 2. BNQ
10m of 1.5mm 3 core cable £10.00 BNQ
1" velcro square pads pads £2.00 BNQ
1 plug £ 1.00 BNQ



total £121.06

cheers matey


just for you

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you might notice i drilled some more holes on the cover, i did this so i could turn
the variacs connectors to the side to make it easier to wire up.



wiring pt 1

i ran the power in & used the connector block, running 2 lives with
2 1A inline fuses to terminals 5 & 8 on the relay holder.

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wiring pt 2

here i run in 2 lines for the 2 fans & connected them to more connector block.

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wiring pt 3

here i daisy chained the earth to the other blocks.

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wiring pt 4

heres the variacs wired up, i used 6.3mm female spade connectors with see through covers.

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wiring pt 5

1 live in - 2 neutral - 3 variable output.

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wiring pt 6

i used velcro pads & stuck then to the relay holder as i didnt have a din rail to connect it
to & i didnt want to drill the case.

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wiring pt 7

here i used self adhesive cable tie mounts to tidy things up.

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wiring pt 8

almost there

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wiring pt 9

here ive ran in the 3 core cable for the thermostat.

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wiring pt 10

Ta Da

heres everything wired up.

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wiring pt 11

heres how the wiring looks when the lids going on, it tucks in with plently of room between the variacs.

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wiring pt 12

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wiring pt 13

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its a great piece of kit & was well worth the effort to quieten things down.
theres no hum what so ever with the 6" high power ruck L1
& the fan runs from as low as 20% & is quite quiet when set to 50%,
you could possibly sleep next to it

wiring pt14

this is how i wired up the thermostat, the neutral wire is the live return & runs to no 13 on the relay.

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heres the inline fuse holders & how they work.

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this is how i stuck things down.

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variacs are also kinder to your fan leepy, electronic controllers send pulses of current through the fan, which is what causes the vibrations, this heats the windings more than the smooth waveform from the variacs and also wears the bearings out quicker. for a 100quid he's got himself A LOT more than what you get with the equivelant airforce controller


JH, that looks the dogs bollox mate wouldn't worry about if you've wired it up wrong, if it works in properly then it's ok, as if you had any mismatched connections on those variacs, trust me you'd know about it. occasionally people get it where the speed goes up when the variac goes down, which is just a case of swapping the live and neutral input to the variac around. just check all your connections and earths and good to go. by the looks of your wiring i don't reckon there's anything amiss!!

if you really wanna go to town on it, wf will get you some little stick on panel legends engraved, just tell them the size of each legend, and what you want it to say and they'll get it made up, either black on white or vice versa. would be easily mistakeable for something from a hydro shop




e2@ much better looking than the panels i knock up, my hole positions are usually measured with..... eye of the builder

dp

foobs, tutu, scraglor, Joint hogger


Chaps i wasnt knocking this build in any way at all i was under the impression this did just the same as the one i posted a picture of and thought why build one wen ya can buy one for about the same doe

Great thread, I'm pissed off with the hum my controller instigates, I've ordered my stat and just awaiting Maplins on the variacs... Great work lads.

WB

I thought so too mate till I wasted £65.00!!!

cheers scraglor
the variacs work a treat but i wasnt sure about the wiring for the thermostat.
as for the fans, no buzzing whats so ever, the fan runs from as low as 20/100 power setting.
i did make the mistake of wiring the neutral & live on the wrong terminals but i soon sorted it.

leepy mate
know you werent knocking it, i was originally gonny get the primair but after all
the reports of them making fans hum/buzz, this was the better option. proper stealth

& thanks to all the kind folk for giving me some help with the build,
i couldnt have done it without your help, cheers JH


my next plan now is to make a single variac controller for the veg cab, itll just be 1 variac,
1 ip66 enclosure, 2 grommit glands & some 1.5mm 3 core cable for the power in & power out.

yeah no worries, didn't think you were, just saying there are a few advantages..

forgot to mention, don't run your fans below 35-40% as there wont be enough airflow to cool the windings

quality JH,

very neat and professional job ya done their. ill be taking some of your ideas when i come to re-wire mine, cos yours is miles neater than mine. plus i dont have them inline fuse holders, would be a good idea to have them on a think.

is the thermo working orite? noticed yours is abit different to mine a think.



dan

dont know yet mate

i put them into the tent on sunday morning under a 600w with the variac set it 50% for the extraction, the 6" L1 fan is barely audible.
then in the afternoon, i drove to holland on the motorbike & have a very close friend checking things daily for me until i get back.

talk about awkward timing

yeah very quiet rnt the?


at least ya got it done before ya went tho eh. and that just sound awsome, biking to holland


dan

Nice build. After having a look at Rasta's stickied post, it'd be nice to get a condensed 'How to build your own variac' type post stickied.

Something listing the components and what to do with them etc. I reckon a lot of people would appreciate that. I was kind of thinking the same as Leepy but if this does way more and better than a Primair or similar then it'd be well worth it. It's guides like this that make UK420 a great place. Good job Joint Hogger.

Thanks Greeny

all the praise goes to rastajedi, scraglor, danlad & others for their help mate.
i couldnt have done it otherwise

jh

Looking to do this myself, i take it the relay just puts 240v on both fans over a certain temp ?

I still can not decide whether to control one fan or two with my 2 variacs ? Have got an 8" so ot sure how loud it is at full (240v).

Hi Guys,
I've got most of the bits to build one today, but I think I'm after a slightly different setup. I've got 2 variacs and I'm wanting to control each fan individually. I understand how to wire that up.

Thing is I can't get my head around the relay bit. Am I right in thinking I would need one relay per variac as opposed to just one here. Is this setup using a variac for min and max? I think thats why I'm confused!

Thanks,
Foobs

still just need one relay. the relay has more than one set of contacts. so you just use one set of contacts for each variac. each fan connects to the common terminal of a set of contacts. then the output of each variac connects to the normally closed contact for it's appropriate fan, and mains connects to the normally open contacts. 240v then goes from your plug, through the thermostat and onto the coil of the relay (only when the thermostat operates of course), and when the thermostat operates it switches the relay on, and the normally closed contacts open breaking the supply from the variacs, and the normally open contacts close, putting full 240v onto the fans

Thanks scraglor I think I understand, although my brain is melting.

I'm using the same relay and holder as JH, so will check on Maplins site to see if there any info on which contacts are which.

I'm still waiting on the thermostat so I'll just wire it without the relay for now.

Right off to BNQ to get the remaining bits I need.

Thanks again, Foobs

if your stuck at anything, dont ask me scraglors the man to ask

only jokin, if i can help then ask away, & dont forget to take some pics as you go along



ATB JH

Thanks JH. I've finished.

I have left out the relay as the thermostat hasn't arrived yet and I don't really need that bit until summer.

I tested it out with a table lamp and both works, although it is brightest at 0 and dim at 100! I read on a previous post that just need to swap live and neutral around.

I'll do that shortly - ETA - sorted...

Here is a pic, it is a bit ghetto compared to yours, but I'm quite a cowboy..

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Thanks to everyone involved, I can now get rid of my Primair

Cheers, Foobs.

not at all matey, if it does the business & its wired securely, then jobs a good yin



also, any chance of some pics of the variac wiring from the side & what things cost you,
having as much info as possible might inspire someone else to give it a try



cheers JH

Lovely builds guys, can anyone give me a pointer on the minimum depth enclosure that could be used to house those variacs?

E2A: minimum width and height would be great too

Hi Goldie

im going to build a single variac for my cab & im going to use a 165mm x 125mm x 75mm enclosure.

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Excellent thread JH, Great pics and very informative...will have to untake such a build at some stage adn will study your posts with detail.

Peace

KDD