Shop OBEX P1 Docs P2 Docs Learn Events
5 volt regulator — Parallax Forums

5 volt regulator

QAHQAH Posts: 13
edited 2007-10-01 18:25 in BASIC Stamp
First of all, I just want to say that I am new to the forum. I just bought a 5 volt regulator from Parallax. It is the same type that is on the Basic Stamp Homework Board. I have a 9-volt battery attached to it. When I take my multimeter and read the output voltage, it only brings·the current·down to 7 volts. Why won't it lower it to 5 volts. If you know why, please let me know.

Thanks [noparse]:)[/noparse]

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-10-01 14:33
    Hello,

    ·· Experimenting is good, but it is also important to understand how a component works before implementing it into a circuit. The datasheet will often provide crucial information. In this case, capacitance…the regulators require a certain amount of input/output capacitance to regulate properly. Please be sure to use the appropriate cap on both the input and output and it should work fine. I hope this helps. Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
  • Mike GreenMike Green Posts: 23,101
    edited 2007-10-01 14:34
    How do you have it hooked up? The input and output capacitors are necessary for proper operation. Look at the first page of the datasheet (downloadable from the Parallax webstore product page). It explains the minimum values necessary.
  • QAHQAH Posts: 13
    edited 2007-10-01 15:00
    Well I have a 9-volt battey, but it's putting out 8 volts due to its use.
  • RDL2004RDL2004 Posts: 2,554
    edited 2007-10-01 16:23
    A minimum load may also be necessary. A red LED in series with a 220 or 330 Ohm resistor should be enough.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Rick
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-10-01 17:04
    Rick,

    Minimum load requirements are typical of switching supplies, but the linear regulator is more dependant on having the correct capacitance on the output. Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
  • StampNut2StampNut2 Posts: 224
    edited 2007-10-01 17:24
    Hello RDL 2004, This circuit I built is a variable 0-9v supply x 3, but the principle is the same This was using a LM350T reg, You can omit the diodes [noparse][[/noparse] Protection of LM 350T and reverse protection at beginning of circuit ]and the 5k variable pot and change the resister R2 , But notice the caps at both front and rear as described earlier in this post, also resistor and led at right [noparse][[/noparse]load] also indicator. Hope this helps out.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Never give up when things go wrong.

    robosapienv2-4mem8.page.tl/

    Post Edited (StampNut2) : 10/1/2007 5:50:29 PM GMT
    LM350T Variable power supply.jpg
    446 x 334 - 38K
  • riverdanriverdan Posts: 21
    edited 2007-10-01 17:32
    here is maybe where you need to go for a better understanding of a power supply the caps will lower the volts.


    http://www.play-hookey.com/analog/experiments/plus_5_volt_ps.html
  • QAHQAH Posts: 13
    edited 2007-10-01 17:53
    I am sorry to say, but y'all are talking waaaaaaaaaay out of my league. Can someone give me a simple explnation, because I am horrible when it comes down to hardware.

    I love making software [noparse]:)[/noparse]
  • StampNut2StampNut2 Posts: 224
    edited 2007-10-01 17:59
    OK, You cannot get any simpler than this, Hope this helps out. www.tkk.fi/Misc/Electronics/circuits/psu_5v.html

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Never give up when things go wrong.

    robosapienv2-4mem8.page.tl/
  • pwillardpwillard Posts: 321
    edited 2007-10-01 18:25
    Lets back up a step. You can read a schematic, right? (or not, maybe that is where we need to start) If we are talking way out of your league, we might need to find you a pictorial example. There is a breadboard power supply assembly tutorial here: http://www.play-hookey.com/analog/experiments/plus_5_volt_ps.html

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

    There's nothing like a new idea and a warm soldering iron.
Sign In or Register to comment.