527,808 active members*
2,469 visitors online*
Register for free
Login
Results 1 to 7 of 7
  1. #1
    Registered
    Join Date
    Nov 2015
    Posts
    341

    PWM to analog 0-5VDC converter

    I am trying to find a way to connect a CNC controller that has a 1kHz 5V PWM output to a spindle drive that accepts 0-5VDC (input) analog signal.


    There are several PWM-To-Analog converters on the market similar to this - Link (attached image).


    Unfortunately, they all convert 5V PWM signal to 0-10VDC. That means at 100% PWM cycle duty they output 10V. My spindle drive accepts up to 5VDC.


    Do you know any converters that may work in my case, or can you suggest any walk-around to this problem?
    Any advice would be greatly appreciated!




  2. #2
    Registered
    Join Date
    Nov 2012
    Posts
    931

    Re: PWM to analog 0-5VDC converter

    The easiest way is to add a voltage divider between the converter board and your spindle drive. Something like 1K potentiometer should work fine for testing, then you can replace it with two fixed resistors if everything works.

  3. #3
    Registered
    Join Date
    Apr 2005
    Posts
    182

    Cool Re: PWM to analog 0-5VDC converter

    The easiest way is to make an integrator, i.e resistor-capacitor network:
    Code:
    PWM >---/\/\/\/\----------> 0-5VDC
                        |
                       ___
                       ___
                        |
                       GND
    Resistor: 1k, capacitor 1uF
    Make no mistake between my personality and my attitude.
    My personality is who I am. My attitude depends on who you are.

  4. #4
    Registered
    Join Date
    Nov 2012
    Posts
    931

    Re: PWM to analog 0-5VDC converter

    Quote Originally Posted by ZASto View Post
    The easiest way is to make an integrator, i.e resistor-capacitor network:

    Sometimes you can get away with an RC integrator, but usually you need to add a buffer and a filter for best results. The converter already has all that, the OP just needs to divide its output by 2.

  5. #5
    Registered
    Join Date
    Nov 2015
    Posts
    341

    Re: PWM to analog 0-5VDC converter

    CitizenOfDreams and ZASto thank you much for your replys!

    I ordered one of the convertors (the one on the picture). It arrived today and I tested it with an old 10K potentiometer. It worked beautifully.
    Such a simple yet briliant solution. Thank you Citizen!

    You mentioned "two fixed resistors". Can you suggest how to select and where to buy the appropriate resistors? I apologize for the basic questions. You could probably tell I am very inexperienced in this. Usually I just buy prebuilt electronic boards for my machines. I never had to do it on a individual component level.

    What are the advantages of using resistors instead of potentiometer?

  6. #6
    Registered
    Join Date
    Nov 2012
    Posts
    931

    Re: PWM to analog 0-5VDC converter

    You are welcome, I'm glad it worked for you.

    How to select the resistors: you adjust the potentiometer to get the correct voltage, then disconnect the potentiometer and measure it with an ohmmeter.

    There is one trick though. If you are using a single potentiometer, the adjustment will be too coarse and the adjustment range will be too wide. Also, if you turn the potentiometer too far, you may even damage your spindle drive (unlikely, but possible). To prevent that, you can use two fixed resistors and a potentiometer between them.

    Let's say you have a 4.7k fixed resistor, a 0.5k potentiometer and another 4.7k fixed resistor. Then the potentiometer will adjust the maximum output voltage from 4.7 to 5.3V - smoothly and safely.

    As for buying the resistors, check if there is a local electronics store where you live. If you don't have one, ordering online is the next option. There are dealers like Digikey or Mouser, and there are Chinese sellers on eBay/Aliexpress.

  7. #7
    Registered
    Join Date
    Nov 2015
    Posts
    341

    Re: PWM to analog 0-5VDC converter

    Great! I'll do just that. Thanks again!

Similar Threads

  1. step/direction to +/- 10v (analog)converter
    By krummigudna in forum Mach Software (ArtSoft software)
    Replies: 12
    Last Post: 10-14-2009, 03:41 PM
  2. 12vdc from 5vdc
    By TravisR100 in forum General CNC Machine Related Electronics
    Replies: 4
    Last Post: 04-03-2009, 08:32 PM
  3. where to get common 5vdc for g320?
    By Runner4404spd in forum Gecko Drives
    Replies: 13
    Last Post: 02-13-2007, 01:41 AM
  4. Step/Dir to Analog converter?
    By DennisCNC in forum Servo Motors / Drives
    Replies: 3
    Last Post: 12-19-2005, 12:05 PM
  5. Where to get +5vdc for my Gecko????
    By Apples in forum Gecko Drives
    Replies: 10
    Last Post: 09-05-2005, 12:45 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •