Kids Ride on toy LED Project

Discussion in 'The Projects Forum' started by Txanm, May 1, 2012.

  1. Txanm

    Thread Starter New Member

    Apr 27, 2012
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    0
    Great forum here! I have started to get into wiring LED's for a few things, but I am a noob at the design and need some confirmation for my designs. After reading the forums for the past week I think I have the solution but want to make sure.

    I am wiring up my kids electric ride on jeeps with LED's so they can ride at night (on our property, not in a street area). The cars run off a 12V 12AH SLA that is usually 13.5V fully charged. I am guessing on this but the discharged battery will probably be around 8V.

    Question 1: I purchased some weather proof LED's for various areas of installation and I am comfortable with these lights since they are already wired with resistors in place.
    - Do I need to install any Voltage regulator in front of these strips?

    Question 2+: I also bought some G4 12-SMD 5050 LED's off Ebay. I chose these because they were flat & looked like they would be easiest to install in smaller spaces (headlight enclosures). Looking through the threads I am finding the best solution for controlling voltage to these lights is to install a LM317T with resistors. I think I am looking for a 4 volt drop to the LED's, but I am not certain this will be optimal. If I am missing a design thread pointing me there will help greatly.
    - Can I get some help on designing the voltage regulator & resistor sizing for this set-up?
    - Looking over the e-bay page above, what is the power for these, 1.2W?

    Thanks everyone on this site. I am glad I stumbled across it!
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,156
    3,063
    Hard to tell. The ad says working voltage is 12v. I'd be nervous about using them in your system, which might see 15v? when the charger is attached. If the lights never see anything but battery power, you might be OK. Oh, and your battery should never go below about 10v or so.
    Yes, the ad says it uses 1.2W at 12v. Again, I don't know what it means by "12V". Could be fine, but you need to find more detailed info.

    One thing you could do for both LED types is just use a 7812 regulator. It'll make sure the voltage never rises above 12v. Usually, because of dropout, it will operate below 12v. There is also low dropout version.
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,766
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