18vdc convert to 12vdc

[Delboy247]

Hi there anyone here know an easy way to convert 18v dc to 12v dc found a few items on flee bay but just thought if anyone can give me any of there thoughts thanks.

 

[tazz]

Hes only looking for 1/2 amp so lm7812 will eat it, Heatsrink good idea Grant

 

[DPG]

Hes only looking for 1/2 amp so lm7812 will eat it, Heatsrink good idea Grant

Post #3 doesn't make sense then. Daz

 

[tazz]

well i have state 1amp max, so i presume its ok

 

[DPG]

Delboy, can you confirm current requirements? You're going to be burning your reg out if you're not careful. Daz

 

[Delboy247]

Hi I like the interest in this basically the Bluetooth adapter I want to hook up states that it needs 1a supply so what tazz as stated the lm7812 will be sufficient is this correct.

 

[DPG]

Apologies, the 'maximum 3' confused me. Do what Tazz says and all will be good. Daz

 

[Delboy247]

Thanks dpg say if I was to plug my iPhone in this would this damage I hate to blow four hundred notes I know the iPhone needs 0.5a to charge.

 

[Delboy247]

Input range: 24V DC
Output voltage: 12V DC
Output current: 3A (Max) / 36W
Case material: die-cast aluminium
Potting material: epoxy sealed
Brand new sealed
Dpg I see this on flee bay would this be any good ?

 

[DPG]

NO! iphone is 5V not 12V. Don't do this! Daz

 

[Delboy247]

Yeah your right I plan to use a USB plug which steps it down to 5v the iPhone needs 1.5a at 5 volts
This is the plan 18v 2.5a stepdown to 12v with lm7812 to a ciggi socket with a usb plugged in that will step it down to 5v tazz is saying with the lm7812 will give out a maximum of 1 amp which would be sufficient lets say if I plug in my iPhone will this be ok as it needs 0.5 amp charge.

 

[DPG]

I'm still confused - you say the iphone neeeds 1.5A at 5 volts. If so, the 1A reg is not sufficient. Daz

 

[Delboy247]

I'm still confused - you say the iphone neeeds 1.5A at 5 volts. If so, the 1A reg is not sufficient. Daz

Sorry my bad 0.5 fat fingers.

 

[DPG]

Seems a bit messy and open for error this. Changing from 24V to 12V then to 5V. Just buy a 24V to 5V adaptor maybe? Daz

 

[DPG]

This might be worth a look: Car charger for Apple iPhone 4, 4S 3GS 3G In Car Charger 12/24 Volt CE APPROVED | eBay

261067010716

 

[Delboy247]

This might be worth a look: Car charger for Apple iPhone 4, 4S 3GS 3G In Car Charger 12/24 Volt CE APPROVED | eBay

261067010716

Yeah I think this will work for the iPhone that's not my intention to be honest but good to know it was the Bluetooth adapter that I want to sort out its a belkin Bluetooth audio receiver if u don't mind looking at the spec and let me know your thoughts.