enter image description here

Is there a way to detect if the load is conected on the circuit above? (The other load should be connected to the F Pad, sorry for the mistake).

  • \$\begingroup\$ Put a resistor in series with the output, check if there is a voltage across it. \$\endgroup\$ – dim Mar 1 '18 at 12:52
  • 1
    \$\begingroup\$ Are you sure that both LOAD terminals should be connected to the N terminal ... ? \$\endgroup\$ – brhans Mar 1 '18 at 12:58
  • \$\begingroup\$ You are right, one is connected to the F pad \$\endgroup\$ – Tulio Souza Mar 1 '18 at 13:05


simulate this circuit – Schematic created using CircuitLab

Figure 1. Current indicator.

Something like this may work depending on your load current. The diode bridge will drop about 1.4 V at a reasonable current and this should be enough to light an infrared LED as found in an opto-coupler. I've shown two arranged back to back so that a pulse could be detected on each half-cycle.

I have not tried it.

enter image description here

Figure 2. A current transformer and indicator lamp.

Devices such as that in Figure 2 are a safer means of accomplishing the task. In this case the visible LED can be replaced by an opto-isolator LED but get a back-to-back type or put a reverse diode in parallel so that there is a current path on both half-cycles.

The othe


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.