Search results

Search Forums New Posts
  1. BobK

    where would I buy a 300 amp 1.5 volt transformer

    Don't encourage him! Bob
  2. BobK

    PICaxe Vs PIC

    No, I am basing it on the PIC12F1840 datasheet. It does have pullups. It is possible they are not supported by the PICAXE software, but they are there. Bob
  3. BobK

    Digital Pot setup

    Your design is way too compilicated. I can eliminate 2 of the 7 parts. The pullups are not needed as their are internal pullups you can enable :) Justin, The first step would be to get the PICAXE development system, which I believe is free. Perhaps CDRIVE could tell you how and point...
  4. BobK

    12VDC / 1.2A ... from a vehicle battery

    It is okay as long as the battery is 12V. Of course it would only draw power when in use. Bob
  5. BobK

    Digital Pot setup

    In 1979 my group at Digital Equipment Corporation got one of the first VAX-11 780s. It only cost about $1M and had an entire 1Mbyte of that new-fangled semiconductor memory! I worked on the COBOL compiler. Bob
  6. BobK

    12VDC / 1.2A ... from a vehicle battery

    If the vehicle has a 12V battery, you can run the device directly from it. If it is a car (not a motorcyle or truck) it almost certainly has a 12V battery. The easiest way to do this is from the lighter socket which you can get a plug for at Radio Shack. Just get the polarity (+ and -) right...
  7. BobK

    Digital Pot setup

    That chip has a DAC with 32 steps, so it would be very easy to put out an analog voltage in 5 steps to a single ouput pin. That is the way I would do it. Bob
  8. BobK

    homemade chronograph for archery

    Cool. I guess we can now quantify "as fast as an arrow." Bob
  9. BobK

    homemade chronograph for archery

    Just curious, what is the function of "chronograph for archery?" Bob
  10. BobK

    Cutest Component

    Well, I don't swing your way, so my choice would be Ms Inductor, sounds like seductor. Bob
  11. BobK

    Digital Pot setup

    Sorry, I got carried away. The point is that once you are using a microctroller, the digital POT becomes an unnecessary part of the equation. There are multiple ways to create a 0 to 5V signal from a microcontroller. And you said your motor controller could be controlled by such a voltage...
  12. BobK

    Extend Dell LCD Screen?

    Sorry, I didn't notice that that was a laptop you were talking about. I thought you were just trying to extend a monitor cable. Bob
  13. BobK

    32 I/O Data Acquisition board architecture required

    Do you really think you have given us enough information? Do you think these things might matter: The number of samples you need to take per second on any input. The total number of samples for all inputs per second. What you do with the samples after they are acquired. For Analog, what...
  14. BobK

    Digital Pot setup

    On second thought, you don't even need the digital POT with the PICAXE. If it has PWM output, you can produce the 0-5V signal just by filtering a PWM with varying duty-cycle through a simple RC filter. And newer PICs even have a 32 level D/A, which would do this ever more easily. Don't know...
  15. BobK

    Digital Pot setup

    I have not used PICAXE, though I use PICs programmed either in C or assembly. I think the idea of using a PICAXE is very good though. Less hardware actually than messing around with an oscillator and counters, and much more flexible in the long run. Basically, all you would need is the...
  16. BobK

    Current meter is burning out microcontrollers

    You measure current using the Ohms setting right? :) Bob
  17. BobK

    using potentiometer in circuit

    First of all, you MUST measure the current draw from a stiff 1.5V supply before calculating the resistor. Do you have any test equipment? Second, If you use a resistor to drop the voltage from 2.8V to 1.5V you will have to calculate the power in the resistor and choose an approriate rated...
  18. BobK

    Current meter is burning out microcontrollers

    Have you tried running these devices off the 4.5V battery without the multimeter? Bob
  19. BobK

    how can i find led specs

    If you are talking about 3mm or 5mm round leaded LEDs, what CocaCola said. I would add the the voltage drop depends ,more on the color than the power. Red will have the lowest, 1.8 to 2.5V. Blues and whites will be more like 3.3 to 3.6V. All of the higher power LEDs I have ever seen are...
  20. BobK

    GPS recommendation. help!!! than you!!!

    CNET.com is a good site for consumer electronic reviews and recommendations. Bob
Top