Voltage Conversion Question

[ZebrasKneecaps]

Hopefully, someone here can help me.

I have a set of speakers that are normally connected to my laptop, but, as part of a project, i want to have them installed in the car (nothing to do with the stereo system).

In the primary speaker, there is a transformer that converts 240v ~ 50Hz to 6v ~ 0.2A which is then connected to the circuit board containing the power on/off, volume control and headphone socket.

As my car kicks out 12v from the battery, could i connect the circuit board straight up to the 12v supply? would this fcuk it up? and if so, whats the simplist way to get this working?

Hope i've explained this clearly enough. if theres any grey areas, then let me know and ill try to explain a bit more.

Cheers DT_Xtremez_09:

 

[ZebrasKneecaps]

Could i use the same transformer thats in the speaker? or is that just made for converting a 240v input?

 

[pie sandwich]

As far as I know ( I stand to be corrected) but the car batt will be 12v DC. You may need AC.
If you strap a multimeter across the terminals of the batt to find out if it is AC or DC and mesure the Amps and freq's with the engine running and without.

That will help.

 

[ZebrasKneecaps]

As far as I know ( I stand to be corrected) but the car batt will be 12v DC. You may need AC.
If you strap a multimeter across the terminals of the batt to find out if it is AC or DC and mesure the Amps and freq's with the engine running and without.

That will help.

Ahhh...... Im getting the feeling ive bitten off more than i can chew!!!

I haven't got my own multimeter. would it say on the battery?

 

[Moz_Magister]

plus the battery will kick out up to 200A (needed to start the engine) which sounds dangerous for the speakers to me

I think a new transformer would be the way forward.

 

[rest have risen above me]

The clue is in the title the transformer transorms one voltage to another ie 240v to 6v. That 6v ac is the rectified to 6v DC your best bet is to get a multi output cigarette lighter power supply and modify to suit. The bonus is that a shop bought one will be stabilised so less messing around with stuff from the maplins catalogue.

PS when they invent the AC battery let me know. LOL

 

[SecretSquirrel]

Dead right. Your car battery will be DC. The speakers are designed to run off mains voltage. Also the battery will kick out a huge current when starting, not good for small laptop speakers.

 

[pie sandwich]

Also it will kick out more amps if it is for a diesel car than a petrol.

This is why us fairys are gods DT_Xtremez_30:

All that wiggaly amps and witchcraft.


TRHRAM.

In my fervant imagination they have invented AC Batt's, something to do with Dilythium crystals DT_Xtremez_30:

 

[ZebrasKneecaps]

Would it be a better idea to leave the mains plug and the transformer with the speakers and then just get one of these?

http://shop.ebay.co.uk/items/_W0QQ_nkwZcarQ20toQ20mainsQ20inverterQQ_fromZQQ_mdoZ

 

[rest have risen above me]

just re read your first post. without seeing the set up it's a little difficult to work out whether there is a rectifier in the circuit already. Take it down to the 2nd line geeks in the Avionics bay and I'm sure they'll put you right on what you need. (For a small fee lol). BB You're not a rigger are you? As your knowledge of wiggly amps is less than a plumber and thats bad....lol

PS a fairy claiming an AC battery hold your head in shame.

 

[ZebrasKneecaps]

just re read your first post. without seeing the set up it's a little difficult to work out whether there is a rectifier in the circuit already. Take it down to the 2nd line geeks in the Avionics bay and I'm sure they'll put you right on what you need. (For a small fee lol). BB You're not a rigger are you? As your knowledge of wiggly amps is less than a plumber and thats bad....lol

Intelligence Analyst, and we dont have a fairy bay where i am unfortunately.

I can tell you what something is, i just cant tell you how it works!!

Let the **** taking start!!! haha DT_Xtremez_30:

 

[rest have risen above me]

Would it be a better idea to leave the mains plug and the transformer with the speakers and then just get one of these?

http://shop.ebay.co.uk/items/_W0QQ_nkwZcarQ20toQ20mainsQ20inverterQQ_fromZQQ_mdoZ

That would work as long as the power consumption is less than 75w which on the output figures for the transformer you state will be well within. Not a very graceful solution but practical and still retains functionality ith the speakers if you want to use them elsewhere.

 

[pie sandwich]

PS a fairy claiming an AC battery hold your head in shame.

You may want to look HERE They make AC Batt'sDT_Xtremez_30:



Fecking leckie's I sh1t'em DT_Xtremez_30:

 

[Talk Wrench]

As far as I know ( I stand to be corrected) but the car batt will be 12v DC. You may need AC.
If you strap a multimeter across the terminals of the batt to find out if it is AC or DC and mesure the Amps and freq's with the engine running and without.

That will help.

@kin ell Pie, Tell me where I can get hold of an AC battery,DT_Xtremez_35: I could market that and make millions.


BB,

You can buy a relatively cheap inverter which will plug into the cig lighter. It will convert 12 vdc to 220 ac.
They're about 50 British quids


TW

 

[rest have risen above me]

The first line says it all. It is not a battery but a power cell or battery pack.

Some specialist battery packs have built in electronics such as inverters which generate the AC power from the battery's DC output voltage to provide portable mains power remote from the utility supply grid or emergency mains back up power.

And who are you calling a leckie...?

 

[SecretSquirrel]

HA! HA!

A DC battery with an inverter - hardly an AC battery!

PieSandwich - how could you charge an AC battery?

 

[ZebrasKneecaps]

Thanks for your help guys.

Im getting the feeling i asked a really noddy question!!! DT_Xtremez_09:

 

[Talk Wrench]

Off Topic

Mid 90's on Harriers, and our new lecky mech was tasked with a battery change on one of the cabs.

707B simply stated 'A/C battery due bay maint. Replace A/C batt.'

An hour or so later, our slightly befuddled mech returns to TM's after depanelling most of the aircraft and said.

"I could only find the DC battery, I haven't got a clue where the AC one is and I've looked everywhere"


SLABBED.


TW

 

[rest have risen above me]

Thanks for your help guys.

Im getting the feeling i asked a really noddy question!!! DT_Xtremez_09:

Obviously didn't analyse the question intelligently.....lol

If you've no decent fairies where you are you could try the C4i guys one of them in the section is usually a wanabe avionics bod enough to have some idea of the workings of the equipment not just how to reboot windows.

 

[SecretSquirrel]

DC to DC!

DC to DC!

I'm guessing that the transfomer will convert mains voltage to 6V DC. Therefore the input to the speakers is 6V DC, not AC. This would mean the speakers could be run off the car battery but would need to be stepped down. You can pick up converters relatively cheap which will run off your car's cigarette lighter, but it's best to see a lecky and get one wired in.

Here's a cheap one that should do the trick.

http://cgi.ebay.co.uk/DC/DC-Car-Con...937100QQcmdZViewItem?IMSfp=TL0806171024a15020