Announcement

Collapse
No announcement yet.

Need a very small 12Volt regulated PS 60 mA min

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Need a very small 12Volt regulated PS 60 mA min

    Hey does anyone have some good ideas on how to get a very small in size regulated 12V supply that will supply a minimum of 60 mA, or around 60 mA as this is the max the module needs?

    I need it for a small relay module, and the smaller the better for th power supply, as it needs to go in a very tight area.

    Would like a fairly hardy solution as it is going in a very turbulent environment (quite literally shaken during use but will be in a padded foam box)

    I was thinking something I could hack up is a cigarette lighter adaptor as it is small, though not sure if this is what is considered regulated. any input somone could give me on this route?

    I also know there is away to take a small circuit and build a 5v output, but I need a 12 v output is there something like this that is very small cheap and comes in a kit so I don’t have to track down parts?

  • #2
    I just wanted to clarify that that I am looking for a DC to DC converter, as I did not explicitly say DC to DC.

    The ones at the store are much to physically large for my needs and supply way to much power for my needs.

    Comment


    • #3
      Out of curiosity, care to explain your project a bit and what your goals are? I can't help you with the PSU, but I'm curious

      Comment


      • #4
        The fairly common one :

        http://www.national.com/pf/LM/LM78L12.html

        Its a 12V 100mA regulator, you can get them in surface mount as well.

        Comment


        • #5
          Originally posted by WoLLy
          Out of curiosity, care to explain your project a bit and what your goals are? I can't help you with the PSU, but I'm curious
          It’s a little bit of a unrelated topic to this forum, but…….this is for a amplifier running in a pelican waterproof box. It will be going in a 99 seadoo gsxl that I have modified to accept speakers, and am currently working on making stock momentary switches turn the amplifier on/off with a small relay module. The handlebar has a ipod control built, and the ipod is in a waterproof bow that is accecible in the front compartment that is the source for the amp

          This relay module needs a clean 12V source to operate properly (I was told) , and extra space is at a minimum!






          Comment


          • #6
            Originally posted by Chris31
            The fairly common one :

            http://www.national.com/pf/LM/LM78L12.html

            Its a 12V 100mA regulator, you can get them in surface mount as well.
            Thanks Chris31, can you tell me the specific part number I will need?
            Those things are confusing when reading and not sure what you are looking at!


            This will be a application that will have greater than 12 volt supply to feed the regulator, is there one that will work best for a automotive like environment?

            Will this have a problem if the line spikes to ~14.4 when charging the system?



            Is this just a mosfet based regulator, similar to the 5 volt ones I am accustomed to seeing schematics for?

            Will any of the other components be necessary that are on the 5 volt schematic?

            Comment


            • #7
              The LM78L12ACZ is probably the one you need, its a TO-92 package looking like this >>> http://www.national.com/packaging/folders/z03a.html

              The LM78L12ACM is the SMD version >>> http://www.national.com/packaging/folders/m08a.html

              Go for the TO-92 as they are very common type. The generic part number is 78L12, which mean 12V 100mA on TO-92 package.

              Comment


              • #8
                Yes that regulator is the same family as the one you described. It should be able to take something like 35V, you may still need protect it against a spike. Simple one uses a low value resistor + a cap just to absorve the spike before it reach the regulator IC.

                Bear in mind that you will need an input voltage of maybe 14V for it to output a 12V.

                You can look for a low voltage drop version of it.

                Comment


                • #9
                  So is this more like the one you are describing?

                  I just don’t want to leave anything to chance or assumption, as I don’t know the first thing about this stuff, or rather I know just enough to be dangerous.

                  I can solder almost anything under the sun, and this will be a easy task, I just don’t know anything about the hardware in question.

                  Can you point me to a schematic that you would recommend, if these are not sufficient?



                  Are there any places that would supply the parts in one kit so there is no room to mess up when ordering? And maybe even have a small PCB made up for it?

                  Thanks!

                  Comment


                  • #10
                    Does anyone know of a kit that would include the parts, and or a source for a small PCB for a small circuit like this?

                    Looked at ratshack and locally, but couldn’t find a lead.

                    Comment


                    • #11
                      Just use stripboard, it easier unless you really must use PCB.

                      The circuit above is a fairly standard one but you may wanna consult the datasheet for the recommended capacitor values.

                      Comment


                      • #12
                        You "probably" could get away with a 7812 from radioshack with such a small load. Normally you do need 1.5 over output, but IIRC, the drop is related to load. I've used them in car projects before and got decent regulation even when the alternator isnt' running. (Though I use Low drop out regulators now)

                        Maybe not ideal, but they are easy (usually) to get locally.

                        Are you driving a relay coil with this?

                        If space is at a premium you could use a zener diode. Regulation won't be as good, but might work, certainly compact. Again, usually available locally.
                        GE Cache Builder | [email protected] |Coolstuff :autospeed.com | bit-tech.net | Nitemax Ultra Pinouts

                        Comment


                        • #13
                          Hey shotgun I found this browsing around from a link from your other thread, do you or anyone feel this might work?

                          It says regulated, and I think it has all the components mentioned from limited viewing angles.


                          The only problem with it might be every cig adaptor that I have found, doesn’t seem to be a true 12v regulated source.

                          All seem to go past 12 volts when higher voltage is applied.



                          Detailed Description
                          Cigarette Lighter Plug Power Supply Board - Small circuit board was meant to fit inside a cigarette lighter plug and convert 12VDC to a regulated voltage for charging cell phone nicad batteries. Has IC, diodes, LED indicator, various resistors, capacitors, miniature fuse, etc. Sorry no other info, brand new - board only - no plug. Package of 2. G1676






                          http://www.goldmine-elec-products.co...p?number=G1676

                          Comment


                          • #14
                            Originally posted by rotarypower101
                            Hey shotgun I found this browsing around from a link from your other thread, do you or anyone feel this might work?

                            It says regulated, and I think it has all the components mentioned from limited viewing angles.


                            The only problem with it might be every cig adaptor that I have found, doesn’t seem to be a true 12v regulated source.

                            All seem to go past 12 volts when higher voltage is applied.



                            Detailed Description
                            Cigarette Lighter Plug Power Supply Board - Small circuit board was meant to fit inside a cigarette lighter plug and convert 12VDC to a regulated voltage for charging cell phone nicad batteries. Has IC, diodes, LED indicator, various resistors, capacitors, miniature fuse, etc. Sorry no other info, brand new - board only - no plug. Package of 2. G1676




                            http://www.goldmine-elec-products.co...p?number=G1676
                            Probably would work. Looks just like a 7812 with caps, a reverse proteciton diode, led and fuse.

                            Some regulators you need to load before they regulate. Meaning with nothing connected will basically show near the supply voltage. You can test this by connecting an appropriate resistor between the terminals (for ~12v a 480ohm resistor will limit the current to 25ma) , then measuring with a multimeter.

                            Though I'd still put a quenching diode on the relay coil if it doesn't have them built in.
                            GE Cache Builder | [email protected] |Coolstuff :autospeed.com | bit-tech.net | Nitemax Ultra Pinouts

                            Comment

                            Working...
                            X