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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> moving message display https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1237982908 Message started by rocky3 on Mar 25^th, 2009, 12:08pm

Title: moving message display
Post by rocky3 on Mar 25^th, 2009, 12:08pm

Hi, i have an LED message display unit, its supplied with a 5volt power adaptor with connecting cable to mains, is there any way i can connect this unit to a cigar port in a vehicle to operate it while mobile?

Title: Re: moving message display
Post by Lectrician on Mar 25^th, 2009, 2:20pm

Yes.

Firstly though, is the 5v input shown as AC or DC? Can you find the mA rating of either the sign or the transformer you normally use to plug it in?

Can you see a visible symbol like these? Which is it?

With these extra details we can help you make an informed purchase of a suitable lead over the internet.

Title: Re: moving message display
Post by rocky3 on Mar 25^th, 2009, 2:42pm

Thanks, the 5volt input is DC, and the symbol is the bottom one on your post.

Title: Re: moving message display
Post by rocky3 on Mar 25^th, 2009, 2:48pm

It also says on the power adaptor TH-5V6A-R

Title: Re: moving message display
Post by Lectrician on Mar 25^th, 2009, 3:12pm

Something like this would suit:

http://cgi.ebay.co.uk/DC-CAR-ADAPTOR%2fCONVERTER-2100MA-3V%2f3.3V%2f5V%2f6V%2f6.5V%2f7V_W0QQitemZ170311780473QQcmdZViewItem

You would need to ensure you set the voltage correctly and did not allow anyone to alter that!

It comes with a selection of plug ends which you simply plug onto the lead. Switching the plug 180° will reverse the polarity (and two diagrams above).

A fairly good price too.

Title: Re: moving message display
Post by rocky3 on Mar 25^th, 2009, 5:56pm

Thanks for that

Title: Re: moving message display
Post by londonman on Mar 25^th, 2009, 9:33pm

Hey, Rocky, man after my own heart.

So you're going to stick it in the back of your motor with three pre-programmed phrases.

1) Please don't drive too close

2) You're still driving too close

3) Get the f**k out of my boot!!
;D ;D

Title: Re: moving message display
Post by CWatters on Mar 26^th, 2009, 12:00am

Hold on a moment.. Is it possible that "TH-5V6A-R" means 5V 6Amp? In which case the suggested power supply is too small at only 2.1A.

Need to check what current it really needs. Those LED arrays can soon add up.

Title: Re: moving message display
Post by Twobarrows on Mar 26^th, 2009, 7:43am

Eerrrr......... didn't he say he already has the mains adaptor, but wants to power it from his car? A bespoke adaptor would be pretty easy to design / make, but I'm too busy with other things right now.

Title: Re: moving message display
Post by CWatters on Mar 26^th, 2009, 10:19am

Yes that's right but how much current does the car adaptor need to deliver? eg What does the display require?

The part number for the mains adaptor he has hints that it might be rated for 6A (eg 30W). The car adaptor suggested above is rated for only 2.1A (10.5W).

Edit:

Finding a 12V to 5V 30w car adaptor off the shelf isn't easy (at least I couldn't google one) Most car adaptors of that power rating are for laptops and produce 15V rather than 5V.

If the display needs 6A (30W) and you can't find one either you could use one of these to turn 12V into 240V AND then the mains adaptor supplied with the display. Less efficient but would work fine.

http://www.maplin.co.uk/Module.aspx?ModuleNo=218810

A smaller and more efficient solution (but more expensive) would be to buy a DC-DC converter module. Farnel has them but at a price. You also need a cigar lighter plug etc

http://uk.farnell.com/sunpower/sds-030a05/converter-dc-dc-35w-5v/dp/1254988

If the thing does indeed take 30W then probably best not to leave it running for too many hours with the engine off. The battery might have the capacity but car batteries don't tend to live long if deep discharged.

Title: Re: moving message display
Post by WOLF on Mar 26^th, 2009, 1:35pm

if the guy has a mains to 5v adaptor/transformer,( which was his first statement in his question!!!) then all the guy needs is an inverter, and toolstation do one for less than £30.... upto 300w i have one in my works vehicles so... if in the middle of no where we need to charge the cordless batteries we can!!!

http://www.toolstation.com/shop/Electrical/Extension+Leads+RCDs/Power+Inverter+300w/d190/sd2470/p18128

as that stuffed animal on the ad on tv states......

SIMPLES!!!!!!!!

gawd, life is complicated enough with out adaptors from this to that an back again....

Title: Re: moving message display
Post by Twobarrows on Mar 26^th, 2009, 1:37pm

I do apologise, ignore my post, I looked at the adaptors at the top of the e-bay page which were mains!! What a plonker!!

wrote on Mar 26^th, 2009, 7:43am:

Title: Re: moving message display
Post by Lectrician on Mar 26^th, 2009, 3:23pm

I guess we had better wait for the 'mA' or 'A' figure from the current transformer or ideally the sign itself.

If you cant find a 'mA' or 'A' figure, is there a wattage printed (w)?

Title: Re: moving message display
Post by CWatters on Mar 27^th, 2009, 8:29am

TIMBA-WOLF wrote on Mar 26^th, 2009, 1:35pm:

if the guy has a mains to 5v adaptor/transformer,( which was his first statement in his question!!!) then all the guy needs is an inverter,

That's what the maplin link I posted is...

£20 http://www.harcon.co.uk/slatetileridge/ridgeline.aspx

Title: Re: moving message display
Post by rocky3 on Mar 27^th, 2009, 2:52pm

Thanks for all the info guys, while looking at Ebay i found a scrolling display purpose made for cars costs £19.99 so ive bought that seemed the easier option.