SCT with Mono Audio Jack(2 wires only)

mohammedbenhadine · 2020-08-17T15:28:49.846Z

Hi there,
I’ve a set of SCT013 sensors but with 2 wires only (a mono audio jack) and i want to use them with my emonTx V3.4.
After a check to the schematic i figure out that 3 wires are used to connect the currenttransformer holder to the board , additionally i see that the compatible currenttransformers , in pictures with the emonTx , are all with a Stereo Audio Jack.
Is there a way to adapt my SCT to emonTx?

2020-08-173376×5984 2.37 MB

Robert.Wall · 2020-08-17T15:49:31.495Z

Welcome, @mohammedbenhadine

No, there is nothing that you need to do. Just insert your mono jack plug into the socket on the emonTx - the ring (the right-hand audio) connection is not used. The c.t. secondary wires connect only to the tip and sleeve of the plug, when it is a stereo one.

mohammedbenhadine · 2020-08-17T15:52:25.690Z

Aah okey , so there’s no ground that should be connected ?

Robert.Wall · 2020-08-17T16:29:40.048Z

Correct - or more precisely, no screen. If you do feel a need to connect the cable screen, it should be to the plug tip, because that is at +1.65 V d.c with respect to ground, but an a.c. ground. The actual signal input is the plug sleeve (as you can see if you look at the circuit diagram).