Recent content by mgh

  1. M

    PID - unstable after applying load

    Thanks for the responses, they are much appreciated. While we did not make any changes today, we had a good discussion on both your points. On Monday we will first try reducing our sample time (that is, sampling more often), and see how the control responds, then probably try to start over...
  2. M

    PID - unstable after applying load

    Hello All, A class I am in is working on setting up a PID control for a 90V motor to control RPM. We are using an Arduino Uno, but not using the PID library (professor wanted us to get experience writing the code ourselves). We manually tuned the constants with no load on the motor, and had...
  3. M

    help with adjustable power supply

    That was what was missing! I disconnected pot terminal #3 from everything, and jumped across the mid-point in the breadboard on the negative rail. So I now have pot #1 connected to supply negative, pot #2 to regulator adjustable, and a jumper on the negative rail to connect the 2 halves of the...
  4. M

    help with adjustable power supply

    Resistance -out to +out is 4.86K with power off. I have my negative supply on the bottom of the breadboard, and positive supply to upper rail on breadboard. My positive supply goes into reg., then out to the other rail on the top of the breadboard. Negative supply is connected to pot...
  5. M

    help with adjustable power supply

    That makes sense. Sorry, not sure what you mean when you say 'transformer common'. The 3rd pin on the pot? Or one of the pins on the voltage regulator? Thanks for the help.
  6. M

    help with adjustable power supply

    Hello All, Playing around with my first project. Trying to build this: http://www.instructables.com/id/How-to-Build-a-Bench-Top-Power-Supply/ My breadboard is a mess, but I attached a picture any way. I am using a 12V wall-wart, and I can use the pot to adjust the output, but, only...
  7. M

    vendor review - Futurlec

    Oh my, and I had hoped to work on a project while I had some time off for Christmas! I am glad to hear others have had good experiences with them.
  8. M

    vendor review - Futurlec

    Hello All, I don't know if this is appropriate here in this forum, if not accept my apologies. I have yet to try my first electronics hobby project. I ordered miscellaneous parts from an outfit called Futurlec on Nov 27th, and have yet to receive anything from them. I got no order...
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