Convert 4-20ma control signal to a 135 Ohm slide wire

[jack marcotte]

Does anyone know what the wiring scheme with resistors is to convert a 4-20 ma signal to a 135 ohm slide wire control to control a 135 Ohm actuator. I know a converter can be bought but I would like to avoid that and simply wire with the needed resistors. Does anyone have this wiring schematic already done. I know someone has done it but it is not sold by the manufacters because it is a cheap solution. A few dollars in resistors.

Thanks

Jack

[dapper]

Good Luck!!!!

[flange]

check the lit on your particular controller, some can be easily configured to do this internally.

[standardgreg]

depending on actuator brand, honeywell and johnson make signal adapters

[amigo]

To make it accurate, you will need many steps hence many resistor combinations and stepper.
May want to save yourself the headache and look at:
http://www.act-solutions.com/pdfs/drn4/drn4_spec.pdf

[Control Man]

Checkout a NEPTRONIC Ki-135 Transducer

Converts 0-10VDC , 2-10VDC , 0-5VDC and 4-20MA to 0 - 135 Ohms

It is a bit BULKY in size( 3.5" H X 2.2" W x 3.5" D ) but does a nice quick job , uses a 11 pin relay socket

[fat eddy]

It's called a DRN, from honeywell

[joey791]

Theres a manual from Honeywell that tells you how to convert using resistors, I have a copy somewheres, what are you trying to do?

If this is on a modutrol you can buy a module for less than 100 dollars from Honeywell that will convert slidewire to 4 to 20, also Kele sells different items that do this too

[jack marcotte]

OK, thanks for the comments I do have a solution and I will send it (The Schematic) when I get done with the job. Just wondered if anyone had a better solution. Mine costs less than 5 bucks in resistors.

[fat eddy]

is it a 232 and two 66 ohm resistors ?

[jack marcotte]

Additional comments: a 135 Ohm slide wire controller requardless of make or model should be able to be controlled with a 4-20 ma control signal and two properly sized resistors. Keep in mind the ma signal varies the resistors don't have to vary. Somebody should be able to figure this one out.

You may need to use the standard 300 Ohm pot that is on a lot of these slide wire controllers to adjust and fine tune the controller action of the dampers.

I'll let you know how I did it after I get done with the job. I'm working on the old M955 Honeywell Actuators.

[fat eddy]

i have never trie dto figured it out the DRN is about 80 bucks, and will control a lot better JMHO