Voltage Switching - Page 2

 

On Tue, 14 Aug 2007 20:12:04 -0700, robert.mcd@gmail.com wrote:


Single-ended or differental?  Are you able to access the device
circuit and power supplies?  Or must you connect to it, without
modifying the device?  When it provides 24V, what impedance and
current compliance does it have?  When it outputs 0V, is this at a
high impedance (effectively open, if single-ended?)  What supplies do
you have for your own circuit?  What are you then driving with your
output?

Jon

 

Since inquiring minds want to know, I will try to get more detailed.
The device I am trying to interface with is a PLC.  On this PLC, I am
using two DO's, that at the off state, output 24VDC, max 2A. When  a
DO is switched on, the output drops to 0V by connecting to an earth
ground in the PLC.  I am inputting to an actuator controller that
requires the off state to be 0V and the on state to be 24VDC with max .
25A.  So the signals are backwards.  When the PLC is at 24V, the
controller needs 0V (at rest); then I flip a switch to create a move,
and the PLC is at 0V but the controller required 24V(move signal).  I
hope this did not confuse everyone.

 

robert.mcd@gmail.com wrote:

I think you need something like this solid state relay.  and
you will have to mount it on a heat sink surface for it to
carry 25 amps.

http://www.newark.com/jsp/displayProduct.jsp?sku=80K9298&CMP=KNC-G10000673&HBX_OU=50&HBX_PK=CRYDOM+D1D40

Connect the control input between the +24 volt supply and
the PLC DO.  Connect the output between the +24 volt supply
and the load.

 



Sorry, that was .25A or 1/4A.   Word wrap ;)

 

robert.mcd@gmail.com wrote:

Well, that's a horse of a different color.

Try:
http://www.crydom.com//userResources/productFamilies/66/crydom_io_odc.pdf
plugged into this:
http://rocky.digikey.com/WebLib/Crydom/Web%20Photos/MS-4.jpg
These are the mini I/O modules and screw terminal plug board
on this catalog page:
http://dkc3.digikey.com/PDF/T072/P1879.pdf