Dropping 12V to 5V using voltage regulator(s)

[BabyGeezer]

No, I meant a USB phone charger that plugs into the cigarette lighter hole in the dashboard of a car.
You just asked for a 12>5volt/1A regulator.
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ahh yes, those are common enough indeed - but i've never had one.

might be worth getting if it had a good enough rating, Thanks !

[Paul__B]

I would never buy one new but ... Garage sales!

[BabyGeezer]

I would never buy one new but ... Garage sales!

better yet, old car in a junkyard ?

[Smajdalf]

obviously they should be properly rated, my stock of resistors are just the 1/4W ones though

You may use several resistors in parallel to get more power dissipation. It won't be nice but it is usable to get it working ASAP.

[PerryBebbington]

Collect wall worts. Any electronic equipment being thrown away keep the wall wort. Ask friends and family to save them for you too. That way you will always have a suitable power supply for pretty much anything.

[BabyGeezer]

You may use several resistors in parallel to get more power dissipation. It won't be nice but it is usable to get it working ASAP.

i see - so, to calculate Ohm's Law - i'd then divide the effective current (for the wattage) by the number of resistors in parallel ? (not forgetting that resistors in parallel also drop the total resistance)

Collect wall worts. Any electronic equipment being thrown away keep the wall wort.
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yep, that's what i've been doing - 5V, 9V but just the one 12V.
and they are all under 1000mA! (i have 500mA, 600mA and 900mA !!)

i should repurpose an old USB cable - i have a phone charger (1000mA) that has a USB socket.

[PerryBebbington]

Yep, that's what i've been doing - 5V, 9V but just the one 12V.
and they are all under 1000mA! (i have 500mA, 600mA and 900mA !!)

I should re purpose an old USB cable - I have a phone charger (1000mA) that has a USB socket.

OK, good!

Well, one of the delights of electronics as a hobby is finding new uses for old things, or getting things to work in ways the manufacturer never intended.

[Paul__B]

i should repurpose an old USB cable - i have a phone charger (1000mA) that has a USB socket.

Which is a bit old.  Most are now rated at 2.1 A (to match the iPad).

Going price should not exceed $5.  Purchased locally (as eBay stuff is not trustworthy).

I have a 52l plastic storage bin full of power supplies (but not all are in that bin and not all are lightweight switchmode).  Trouble is, getting to it in the stack ...  

[BabyGeezer]

Which is a bit old.  Most are now rated at 2.1 A (to match the iPad).

i'm nowhere in the circle of iProducts - the phone charger is actually new, for a chinese brand and that is 1A only.

it's the USB cable that is old, still with a type A plug at the other end.

I have a 52l plastic storage bin full of power supplies (but not all are in that bin and not all are lightweight switchmode).  Trouble is, getting to it in the stack ... 

i haven't quite reached those hoarding levels yet
but i do find the older adaptors that i've "stocked" are quite useless when it comes to the crunch, including a cheapo one supposedly rated at 1000mA but doesn't seem to be able to provide it. (i have an INA219 module otw to start getting proper numbers on my "inventory")