Author Topic: LOL I AM THE BEGINNER ! using lipo battery to light doll house with LED  (Read 4468 times)

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Offline IanB

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Re: LOL I AM THE BEGINNER ! using lipo battery to light doll house with LED
« Reply #50 on: November 30, 2017, 02:01:01 am »
Rather than asking to buy resistors, buck modules, time switches and so on, how about a simpler option?

On the web site selling these, they have LEDs pre-wired with a series resistor for 5-12 V DC:

https://www.modeltrainsoftware.com/smd-chip-leds.html

This is nice, because two of these could be put in series off a 12 V battery. Not only that, but at 6 V per LED the current draw would be much reduced from the maximum. (If we say the resistor is sized for 20 mA at 12 V, then the current would be approximately 4 mA at 6 V.)

So now, we could consider running 12 pairs of 2 LEDs from a 12 V car battery for a total current draw of only 12 x 4 = 50 mA. Over 240 hours that is 12 Ah. That might even work running the 5-12 V LEDs individually off 6 V lantern batteries (which have a nominal capacity of 10 Ah for the alkaline version).

Therefore, proposed solution: Use the 5-12 V chip LEDs with pre-installed series resistor. Group up to 8 LEDs to run off a 6 V lantern battery. Use 3 or more lantern batteries according to the number of LEDs required.
« Last Edit: November 30, 2017, 02:03:03 am by IanB »
I'm not an EE--what am I doing here?
 

Online Ian.M

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Re: LOL I AM THE BEGINNER ! using lipo battery to light doll house with LED
« Reply #51 on: November 30, 2017, 03:01:55 am »
Yep. That would be good.  Brute force it with off-the-shelf parts all from the original supplier to avoid egg on face from failure to deliver to, or failure at, the exhibition.
« Last Edit: November 30, 2017, 03:03:38 am by Ian.M »
 

Offline Brumby

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Re: LOL I AM THE BEGINNER ! using lipo battery to light doll house with LED
« Reply #52 on: November 30, 2017, 04:09:29 am »
I must agree, too.  Getting the LEDs already set up with a resistor makes life so much easier to help out our OP.

If they can borrow a 12V car battery, using strings of 2 in series would save on purchasing lantern batteries.
 

Online paulca

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Re: LOL I AM THE BEGINNER ! using lipo battery to light doll house with LED
« Reply #53 on: November 30, 2017, 01:20:54 pm »

12V DC Programmable timer (like a VCR or kitchen oven timer)
https://www.amazon.co.uk/sourcingmap-Digital-Power-Programmable-Switch/dp/B008999RYY

3V Regulator to give you the voltage for the LED strips (or wire 4 strips in series).

https://www.thebatteryshop.co.uk/yuasa-12v-60ah-620a-silver-car-battery-ybx5075-hsb075-8590-p.asp
(60Ah car battery or borrow one)
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