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  1. MP1

    0-30 Vdc Stabilized Power Supply

    Yes, here is a diagram. Two ways to do it. Both are the same. MP potentiometer.pdf
  2. MP1

    help

    If I translated this correctly, you are talking about the unit having very very low current output? If this is the case, I see that you have 60 volts before your voltage goes into the 1.8K resistor. Using Ohm's law, 60/1800 leaves you only 0.033 Amps of current into the 12 volt regulator. The...
  3. MP1

    0-30 Vdc Stabilized Power Supply

    In reply to the question asked by Derfly, you can connect the potentiometers in series. More importantly, for the fine adjustment, you will want to use a 10 turn or a 15 turn or even possibly a 20 turn pot to give you the accuracy you want to achieve. This should be on the smaller value pot as...
  4. MP1

    EEG Amplifier

    The following link might be an excellent building block to get you started. It is a low voltage (0-1V) voltage to current converter with single supply rail. See Fig. 1 for the schematic. http://www.elecdesign.com/Articles/Index.cfm?ArticleID=2985 Happy soldering! MP
  5. MP1

    0-30 Vdc Stabilized Power Supply

    If the link does not work, just go to www.allelectronics.com and use the search box. Enter pm-200 for the search. MP
  6. MP1

    0-30 Vdc Stabilized Power Supply

    Firefly, they are just trying to say the supply voltage must be a fixed voltage. The other input is the measured voltage and this is what will be displayed. In other words, you would want to add a 9 volt regulator right after the rectifier bridge to supply this unit and the measured variable...
  7. MP1

    EEG Amplifier

    I know nothing about EEG, but in instrumentation it is common to convert the voltage to current and read the current or even convert it back to a voltage in order to keep the noise level to a minimum. Hope it helps you a little. Another thought is that fiber optics are pretty much immune to...
  8. MP1

    Piezoelectric Transducers

    Device is made of a crystalline substance which creates charges of electricity by the application of pressure and vice versa. ;) MP
  9. MP1

    0-30 Vdc Stabilized Power Supply

    Billy: The regulator might get hot with this amount of difference, so you should add a heat sink. Also, in regards to the capacitors, when you add a capacitor to the input side of the regulator, isn't there already one there for the other part of the power supply? When you put two capacitors in...
  10. MP1

    Quick question - Solid state Relay

    Yes, this is solid state. It is just not a relay. I think it is a good circuit to achieve the same goal. Many times someone will refer to the term relay as a switching method instead of an actual device. This is a vey good circuit and I for one will add it to my library. I have been thinking of...
  11. MP1

    Quick question - Solid state Relay

    EMF from the motor is what usually causes a problem in solid state relays when used in this application. You should have no problem if you find a relay that is rated at twice the volt/amp rating of your motor and use diodes to protect it from the EMF. You need these diodes anyway. EMF will cause...
  12. MP1

    Basic electronics

    I do not have a problem explaining how electronics work or attaching a document to help explain. We all have questions at some time. After all, this IS an electronics site. That is what is so great about this community. ;D I have attached an excellent short tutorial on comparators. Hope this...
  13. MP1

    Variable current indicator

    I do not mean to over simplify this, but perhaps this will also help others: You cannot have current until the electrons are flowing through your circuit. The current adjustment is a limiting tool. Use the ohm's law calculation to figure out how you will use it. For example, if your power supply...
  14. MP1

    3-Axis Stepper Controller

    You can make a clock circuit or basically a pulse generator with a 555 timer so that it sends pulses to the step input of the chip. You can check this with the DIR in either position as this will determine the direction of the motor. This is actually a good pre-test to insure you are not...
  15. MP1

    Convert 0-30V 3A PSU to 5A or more

    Why not a 12V zener and a resistor? Keep the parts cheap and the count down this way. MP
  16. MP1

    LM317 Variable power supply

    Hmmmm.....not really sure where this belongs. I have uploaded a voltage calculator for LM317. See the download area as soon as it is available. It is a nice calculator for figuring R1 and R2 for a particular output voltage when using the LM317. Makes less work. ;D MP
  17. MP1

    ATX power supply

    The pdf file has some good information such as how to build the dummy load to test a power supply so that you know it is the supply and not a peripheral. Beyond that, I do not give TJ Beyers much credit (not exactly a friend of mine ;) ). $10 in parts plus a lot of your time when you can buy a...
  18. MP1

    Component dimensions chart

    Billy, the design rules are really not that strict ;D. You have all the latitude you need as long as it does not fail the DRC check. In Eagle, I normally use the resistors from the "Discrete" library. The "Resistor" libraries are for special products such as SIL, DIL and Power resistor types. In...
  19. MP1

    Simple PC thermometer

    I just noticed your post. I have not built this circuit, but it sounds like the message you are getting is related to the computer you are using. What operating system? Do you have administrative rights on the system? Perhaps you are asking the computer to act on an instruction that goes against...
  20. MP1

    LM317 Variable power supply

    Actually, my data sheet lists 3.5 mA as minimum typical load current for the LM317. ;) In referencing a typical 2X16 display data sheet: It is true that the logic current on most LCD displays only draw 1 mA typical, but the lighting draws considerably more. This can be in the 100 mA to 200 mA...
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