One wire current sensing


Active Member
EL34 said:
Cr Magnetics does not sell the CR3110 current sensor on their site, they just give links to distributors.
You may want to give them a call and ask if they still sell direct. They used to sell direct on-line. Their "Buy Now" button goes to a page called placeholder.asp which gives me a hint that this is a work in progress?
I sent them an email and just got a reply, it has a 14 piece minimum.

To follow is our quote on the C R Magnetics parts that you requested. The normal availability is factory stock. All prices quoted are expressed as your net price.

A. 14 EACH CR3100-3000 $11.03 EA.

Note: There is a 14 piece minimum order on this part.

Thank you for the opportunity to quote your C R Magnetics parts needs. If I can assist you further, please call.
Jay Armstrong
PE Products Company, Inc.
621 Moorefield Park Dr. Suite G
Richmond, VA 23236
804-560-0655, 800-849-5655
For your electrical heating, sensing and
control applications, see us on the WEB
Email to: [email protected]
Was that reply from C R Magnetics or PE Products Company, Inc.? I was suggesting you call C R Magnetics.
I emailed CR magnetics right from thier web site.
The reply above and below came back so CR magnetics is refferring emails from their site to PE.

PE represents a bunch of companies as it says at the bottom of the email below.

I just got another email from the guy that wants to handle my account, I would be in his territory. He is from PE also.

Maybe I should just become a distributor and add them to my company shopping cart. Getting a product should not be this difficult. :D

Thank you for your interest in CR Magnetics.  I see where our Jay Armstrong has quoted C R Magnetics to you today as below:

A.  14 EACH        CR3100-3000                                                                $11.03 EA.
Note:  There is a 14 piece minimum order on this part.

I'm responsible for your account.  I'm in Duncan tonight 2/21/07, and heading to Swannanoa NC tomorrow afternoon.  If you feel that we should meet about CRM or one of the other products listed below, please let me know tomorrow morning and I will do my best to stop by your place tomorrow afternoon around 4:00 PM.  Please call me on my cell 804-402-5655

Our business is industrial heating, sensing & controls, and we offer value when it comes to process improvement and cost savings.

I'm an your area every 6 to 8 weeks.  If you feel that I might be of assistance to you at a later date, please let me know, and I'll arrange my schedule to meet yours. 

All of your contacts in our office would be Fawn Capps [email protected], Jay Armstrong [email protected] or Holly Eggleston [email protected].  If yours is a control, drive, oven or chamber need, please contact our Applications Engineer, Ben Hill [email protected]

I look forward to meeting you, and we look forward to your order!

Wilton Ford
PE Products Company, Inc.
621 Moorefield Park Dr. Suite G
Richmond, VA 23236
Local: 804-560-0655, Toll Free:800-849-5655
Fax:804-560-3296, Cell: 804-402-5655
E-mail: [email protected]
For your Electrical Heating, Sensing and
Control needs see us on the Web.

We represent the following Companies: [Items in red are usually in our Richmond inventory]

Tempco Electric (process heater, cast-in-aluminum, immersion, band & cartridge heaters),

Warren Electric (immersion, flanged, screw plug, UL & CSA rated),

PyroShield (High temperature & flame resistant insulation),

Yaskawa Electric America  (AC drives and motion control products)

Eurotherm Controls (PID Controls, Programmers & SCR),

Continental Industries (Solid state relays),

Mercury Displacement Industries (mercury relays),

Red Lion (digital & analog timers & counters, HMIs, panel meters & controls),

Gefran (Melt pressure transducers, linear transducers & PID controls),

Pyromation  (Thermocouples & RTDs),

Mikron or Exergen (Non-contact sensors, thermal imaging, black body calibration sources),

Control Air  (Precision pneumatic & Electro pneumatic controls),

Action Instruments  & Wilkerson Instruments (Signal condition & wireless transmitters),

CR Magnetics (Current transformers, current transducers, current sensing relays),

Meech (Static elimination),

TPS (Ovens, furnaces, autoclaves sterilizers, dryers & environmental chambers),

CassoSolar  (IR Heaters, Heating Systems and Production Lines),

Patt Technologies (Advanced Rotary III polymer filtration),

Solvere (Innovative automation & network Solutions),

Repairs (Free evaluation: instruments, power supplies, SCRs, recorders, printed circuit boards, thermocouples, RTDs, transducers)

Instrument Calibration & Certifications also available
BTW, I am not building the project mentioned at the top of this thread.

I want to sense current running in some of my shop machines

The sensor circuit I build will turn on an X-10 powerflash unit which will then start a X10 macro which will then turn on dust collection systems, lights, etc.
Ok, mystery solved, what a mess.

I emailed Cr magnetics about buying these sensors.
I receive the emails above thinking I am deal with Cr magnetics.

But NO, Cr forwarded my email to PE products without telling me they were doing so.

PE does not stock the part and has a 14 item minimum.

Now PE tells me to phone the factory and see if they will sell me the parts.

WTF, that's what I was trying to do in the first place. :D

I'll keep at this until I reach someone that knows what they are doing. :p
Thanks Mitch,
I ended up emailing Cr Magnetics again.

They said they had forwarded my email to PE but did not know that PE did not stock them and had a 14 unit minimum.

They then offered to sell me two of them, which is what I was trying to do the first time I emailed them. <_<

They are on the way. :D
I know this isn't one wire but I wanted to say that the current sensors work really well. They can be used with one wire also.

I added a new project to my X10 project pages.

I finished the current sensing device that senses when I turn on any one of several dust belching machines I have in my shop.
The current sensor then triggers a X10 powerflash unit.
The powerflash then triggers a X10 SR227
This turns on my dust collection shop vac system.

See project #3 on the page below.