The Hot Seat - 240v power supply

[RB]

Well as promised here's some pics of my latest project, The Hot Seat.
A 240v power supply inverter unit which also doubles as a comfortable seat.
This unit can deliver power through 8 outlets capable of running an assortment of gadgets from laptop chargers, hair dryers, dew zappers, DSLR battery chargers and drive a goto mount and any imaging gear.
It uses a deep cycle 12v battery and has a 240v safety switch with an earth stake as well.

On the control panel there's a volt meter to keep an eye on the battery, and a low voltage alarm. It also has twin 12v cigarette outlets, a RED LED Torch so you don't accidentally trip over it in the dark,
and a nifty little feature - 2 RCA contacts which you can clip a car charger to so the 12v battery can recharge when not in use.

I took this up to Kulnura on Saturday night and we were able to run our gear all night long.

It's also very handy around the farm and a necessary item during blackouts.

Just a word or warning, if you use an 240v inverter out in the field, it's best to house it in some sort of box to prevent dew build up and avoid electricution. These inverters are capable of delivering lethal voltages.


:)

[iceman]

It's a great bit of gear Andrew, very impressive and loved it when I saw it on Saturday night.

You're going to be very popular to setup near at star parties.. and it won't just be because of your beer and pizza supply! :)

Congrats! You should patent it!

[davidpretorius]

beer and pizza, wow, that is a cool box to carry beer and pizza in. does it do anything else ie flashing lights etc :)

[Orion]

Great job Andrew. Also like the colour.

[h0ughy]

Its the Tardis!!!

Nice andrew, How do you lift it?

[iceman]

It's heavy! It's got a big truck battery in it.

But Andrew is a beefcake, so he lifts it with his pinky!

[acropolite]

Well thought out Andrew, with the RCD for safety and an earth stake, you've thought of everything. :)

[Dennis]

Excellent project - thanks for the details. It is always great to see and read about the Do-It-Yourself efforts of others.

Cheers

Dennis

[RB]

Dave it's quite heavy, I plan to add some wheels and a handle to move it into place.
Maybe fill it with Helium too........:whistle:

[RB]

I plan to add a Microwave since a certain member of our's likes his pizza HOT.
You'd think that with a forum name like his he'd prefer things cold. :cold::poke: :lol:

[h0ughy]

what sized battery did you use? AH rating

[cjmarsh81]

Very nice. Must be a bugga to lug it around. Perhaps put wheels and motor on it and it can drive itself back into the garage?
Why did you use RCA sockets for power? Wouldn't DC sockets have been easier. RCA's are normally for audio stuff. Just watch no little ones try to plug any audio equipment into it.

[GrampianStars]

:lol: why not go R/C & add a Wireless Camera :D
It'll drive itself back to the car then

Looks to be a cool beast

[RB]

Dave on the farm here I need a large battery, I'm using a 112 AH rated battery with 930 CCA (cold cranking amps).
Although there's no need to go that high for normal astro use.
If you use a lower rated battery it should be a bit lighter too.



I gave that a lot of thought. I was initially gonna use DC banana sockets but the ones I had didn't fully expose the terminal when you unscrew them and hence makes it difficult to clip the clamps onto.
This way the clamps stay one very well, as you can see in the photo below.

If someone does try and plug audio equipment in there then the music will be very monotonous and anyone lugging around audio equipment at observing nights must be :screwy: than I am......:rofl:

Thanks for your nice comments too, everyone.
Ed I like the colour too, it matches my LX200.

Phil I was relieved at reading your reply to another thread confirming what needs to be done about earthing the inverter. :thumbsup:

:)

PS I like the idea of putting wheels and R/C on it, that way it can deliver it's own Pizza......

[ving]

haha! thats way cool! :)
good work andrew :)

[cjmarsh81]

I didn't realise they were just clamp points. I think a motor is actually a practical idea. Have a push button you can press to make it go forward and drive it into the garage.

[RAJAH235]

Nice....You gonna 'heat' the 'Hot Seat' for those really cold nights? :P :D L.

[RB]

:rofl:
What a great Idea Raj....

:thumbsup:

[davidpretorius]

yes that is because he is a big nancy girl!

(the above post was reread, and i thought about it twice before posting and therefore nearly wrote the same thing twice):rofl:

[cahullian]

Really nice set up Andrew. I was there when you were using the hairdryer at 4 am lol. All the other (bludgers,skivers) people were long gone by then.
What time did you and H call it a night?
Gazz

[RB]

Thanks Gazz, yah we called it a "night" at around 5.30am or so. :lol:

[Striker]

Great project Andrew.

The best thing about this is it's so practical....well done mate

[[1ponders]]

Nice unit Andrew.

So when do you go into production :evil:

[RB]

Thank you very much Tony and Paul. :)

Paul I wish I could go into production unfortunately it's a one off.
I started off with a simple plan for a box and I got carried away....:doh:.......:lol:

[stringscope]

Looks a really nice job Andrew. Really practical too. 100+AH, wow! that is some serious portable electrical capacity.

I can see it would be quite easy to add wheels and telescopic handle similar to a suitcase (but heavy duty).

Thanks for sharing it with us. Are you going to do a "How to" article for IIS?

Cheers,

[acropolite]

On inverter stories and microwave ovens Pizza etc; a decent inverter with a 1200 watt rating will comfortably run a small microwave oven, and as the time in use is usually very short power consumption isn't bad. You can also run a bread making machine to bake bread, however from memory just mixing the dough for 1 loaf of bread bread uses around 30 amp hours. You can also pump water with a 6-700 watt Davey pump, around 7-10AH for 100 gallons (450Litres to the metric hoards). Don't expect an inverter to run a 240V fridge or any other compressor device as these loads have very high startup currents and although the current draw of a 240V fridge is fairly low over 24 hours they consume quite an amount of power (That's if you can get them running on the inverter in the first place).

[Muddy Diver]

Andrew

Great Inverter unit! As a regular camper this unit would impress the hell out of my regular camping buddies who always try to turn up with a new gadget each time. I'm not sure that with the inverter mounted right beneath the seat that you need to install any other form of heating eh? However, the low cost BigW Jump leads shown in your later photo have let the unit down I'm afraid. I tried to use mine during the last camping trip to start a friends car and ...NO GOOD! :doh: I thought it might have been something else with the car but swapping my chepo leads for someone elses real ones started it immediately. I am not the only person to have suffered this I have since learned.

I feel sure you will not be getting the charging rates you could get with a decent set due to losses and well, actually high resistance which is not desireable in 12V circuits eh?

Just a tip.;) NEVER rely on those Low cost leads in an emergency. Sometimes they just dont work.

[RB]

You raise a very valid point MD, although in this case it is not correct.
The clips you see in the other photo belong to a proper 12v charger which I highly recommend for charging car batteries. As you know the car batteries are charged up slowly and don't need such a high current cable as jumper leads do. In the photo below you can see the charger which I use.
The Battery Fighter is a 1.25 Amp battery charger designed to fully charge and maintain a lead acid battery at the correct storage voltage without the damaging effects caused by other trickle chargers.
An IC circuit applies the correct peak charge, then automatically maintains the battery at the perfect float voltage which eliminates battery destroying sulfation. Charger status can be seen via two LEDs showing Power On, Charging, Almost Charged and Fully Charged.
It's available at Jaycar for $79.95 but I was able to get one for $59 at another electronics store which I forget the name of at the moment (not D.Smith).

But MD is right about jumper cables, I DO NOT RECOMMEND the ones from cheap dept stores as you mentioned. Just to show you what I mean have a look at the second photo. I had an old jumper lead from a cheap auto outlet which I got on their extra special discount days in case I can use the clamps for something else. Well I stripped the lead and there's hardly enough copper wire to run your stereo system :scared: let alone start a car.
I stripped a speaker wire (on the left) just to show you what I mean.

I do not recommend these jumper cables at all.
Thanks for bringing that up MD.

[RB]

Thanks Ian,

In my case I need the higher capacity for work too so I went for the larger battery.
I am looking into adding wheels and a handle like you say.

As for a DIY article I think it's best not to since it involves 240v power.
And even though it's from a 12v car battery it's still leathal.
But it's not hard just to use an inverter with a four way plug pack with a safety switch (RCD) built in. Just make sure you use a "grounding/earth stake" to the inverter earth and build a suitable box to keep the dew off it.

Cheers.

[RB]

Also I should add that if you're charging the 12v battery, you should always do it in a well ventilated open space.
I designed the box to open up and allow it to be charged with plenty of air flow.
It also helps keep the inverter cool when operating at it's peak demand.

Cheers.

[asimov]

Hey handy-andy....I missed this thread, sorry!

Nice work mate! If you serve up piping hot Hawaiian pizza's with HOT pepperoni on...I'm there! Need a new working man/farm hand on your farm!??