DC-DC converter - Variable Input - Constant Regulated 12VDC output?

Discussion in 'The Projects Forum' started by pscammp, Feb 22, 2016.

  1. pscammp

    Thread Starter New Member

    Feb 22, 2016
    Hello all,
    I'm new and hoping I can get some good advice for an up and coming project, I hope someone can help me out here ?

    I have a 12V 75Ah Leisure battery which is to be the main power pack for a project I am about to start. I know that once this thing is charged up it could produce way over 12V but as it runs down it could only produce 11.9V.

    One of my pieces of equipment which is an astrophotography camera needs a regulated DC supply of smack on 12VDC, it defiantly can not go above 13V. I have been looking at DC-DC converters but have found out that they either step up or step down but I have not been able to find one which will take a variable input voltage and still maintain a constant 12VDC output if the input voltage is higher or lower than the output voltage. I need to be able to cover a minimum of 30W @ 12VDC for the output.

    Is it possible to make or purchase a module (as small as reasonably possible) which will take a variable input voltage of, lets say ranging from 10-15VDC and output a constant regulated 12VDC @ min 30W (50W would be safer probably) ?????

    Can It Be Done ?

    Many Thanks for any useful advice

  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    Welcome to AAC!
    What you are looking for is a '12V buck boost regulator'. Google gives many hits.
    Last edited: Feb 22, 2016
  3. Evanguy


    Dec 21, 2014
    Ebay has them for around 1-3$us. Some come with heatsinks and lcd screens to view output voltage. they are about 5$us
  4. pscammp

    Thread Starter New Member

    Feb 22, 2016
    Cheers guy's, your diamonds !

    Just learned something new in that the x5 'Boost' DC-DC converters will be no good if the battery
    drops below 12V for a 12V output LOLOLOL

    'Automatic Buck and Boost' is where I need to be so I'll have to pop the Boost's on Ebay when I get
    them from china.....How annoying :)

    I shall be going for the one's which display the output voltage on the PCB and the x6 voltage displays
    I got can also go on Ebay too. This will save me having to painstakingly cutting out 6 holes in my tool
    box....Yum Yum

    I very much appreciate the help
    ronv likes this.
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
    Please post a link to the part you are considering.

  6. Hayukan Rise

    New Member

    Feb 23, 2016
    Hi. I'm new to the site and new to circuitry but... If your input varies but you want your output to be constant could you try doing an inductor to power transistor to a 12v zener diode? That should increase your lower input and then limit it to only 12v to your output. Just a thought.
  7. Bordodynov

    Active Member

    May 20, 2015
    TRACO POWER TEN 50-1212 ==> Input 9V-18V Output=12V Ioutput_max=4.167A, 1" x 2" x 0.4".
  8. pscammp

    Thread Starter New Member

    Feb 22, 2016
    Seems buck/boost converters are few and far between which will cover all my power needs AND have a built on display for the voltage output value, I see the following one from China although it's a bit pricey as I need 6 of them (not all need 6 Amp though, some only need 1 Amp):


    Maybe another option is to have one's without displays of which there seems to be many, hook up some wires from all their output sides, bang them onto a 6 way rotary switch and have a single Volt display unit hooked up to the switches common and I can select each one in turn to set/monitor their output ?????

    Just looked at the TRACO POWER TEN 50-1212 on the Farnell site and it says the minimum input voltage is 18V - No Good

    Cheers Paul
  9. Bordodynov

    Active Member

    May 20, 2015
    Cheers Paul. I used datasheet ==> Input 9V-18V. Read original. TEN_50-1212.png
  10. dante_clericuzzio


    Mar 28, 2016
    Hey i am interested in this but it's quite a price to pay for...is there any chip that can step up and output current more than 10 A?
  11. tcmtech

    Well-Known Member

    Nov 4, 2013
  12. Bordodynov

    Active Member

    May 20, 2015
    See (not low cost ~210 euro)