Dynomotion

Group: DynoMotion Message: 9798 From: tapiolarikka Date: 7/17/2014
Subject: Kanalog ADC?
Hi Tom,

I run my spindle with Siemens Micromaster VFD that has analog out for drive current monitoring.
Manual says that this output is 0-20mA, but has no mentioning of the voltage.
Do you know if this can be safely connected to Kanalog ADC to monitor the spindle/cutter load?

Rgds,

Tapio
Group: DynoMotion Message: 9801 From: Tom Kerekes Date: 7/17/2014
Subject: Re: Kanalog ADC?
Hi Tapio,

You should be able to feed the current into a resistor to convert the current to a voltage.  Use Ohms law:

V = I x R

For example 20ma into a 250ohm resistor would be 5V.  Or 20ma into a 500ohm should be 10V.  There may be some limit on how much voltage the output can provide.  For example into a 5K Ohm would be unlikely to put out 100V.

HTH
Regards
TK

Group: DynoMotion Message: 9803 From: Tapio Larikka Date: 7/18/2014
Subject: Re: Kanalog ADC?

Hi Tom,
 
As last question before I go connecting:
 
What is the voltage limit for kanalog ADC's?
Thanks,
Tapio
 
----- Original Message -----
Sent: Friday, July 18, 2014 1:01 AM
Subject: Re: [DynoMotion] Kanalog ADC?

 

Hi Tapio,

You should be able to feed the current into a resistor to convert the current to a voltage.  Use Ohms law:

V = I x R

For example 20ma into a 250ohm resistor would be 5V.  Or 20ma into a 500ohm should be 10V.  There may be some limit on how much voltage the output can provide.  For example into a 5K Ohm would be unlikely to put out 100V.

HTH
Regards
TK

Group: DynoMotion Message: 9804 From: Tom Kerekes Date: 7/18/2014
Subject: Re: Kanalog ADC?
Hi Tapio,

The nominal range is +/-10V.  You can go to +/-12V without causing damage.

Regards
TK