Harald Posted July 4 Share Posted July 4 Dear Forum, I would like to use my Shelly to query the status of a light switch. The switch output is connected in parallel to the light to be switched. If the switch is set to OFF, the SW input of the Shelly recognizes this as ON. Is this a HW error? Kind regards Harald Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 4 Members Share Posted July 4 (edited) No, it’s a feature, not a bug! The intention of the developers was to arrange that a SW input is activated by live potential AND by neutral potential. Thus, the neutral potential via the lamp (in off state) activates the SW. Switchithe lamp on, live potential across the manual switch activates the input either. Remedy is achieved by (a) an intermediate relay, whose NO contact may activate the SW input, or (b) by a resistor dropped in the wire from manual switch to SW terminal: If desired, I gladly help with a twofold isolated wire with resistor, ready for installation. Edited July 4 by thgoebel 1 Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Harald Posted July 4 Author Share Posted July 4 Thank you very much for your explanation. Have you tested the solution with the resistor? If the SW input evaluates potentials and practically no current flows at this input, a series resistor will not help from my point of view. Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 4 Members Share Posted July 4 Yes, indeed, this is tested. Aim of the resistor is, to prohibit an activation of the SW input with live potential. Thus, only N-potential shall activate the input. Switching the lamp on leads live potential at SW and deactivates the input. This behaviour inverts the switching logic. Hence, the input has to be configured as „Reverse Input“ to correct the inverse logic. Some details to the method of preventing live potential to activate the input: Activation is done by a very small current (approximately 37μA) which is flowing from terminal SW to L if the manual switch is operated. This current is driven by 3V DC. The resistor inhibits this current flow, but allows enough current with the potential of 230V AC which is present between SW and N whilst the manual switch is in off position. You may find further details by searching for „Bukowski Draht“ in the web… Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Harald Posted July 4 Author Share Posted July 4 Thank you, very interesting. Does Shelly actually provide an official specification for the SW input? Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 4 Members Share Posted July 4 (edited) No. The insight was derived by some kind of reverse engineering. Most likely the details are classified as corporate intelligence... 😀 Edited July 4 by thgoebel Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Reinhard Posted July 5 Share Posted July 5 I think I have a similar issue but cannot identify the problem. I want to fade in/out an LED stripe controlled by an OPTONICA LED V1-F (because Shelly RGBW2 does only support 3000ms fade) I am using this circuit. Shelly is configured with auto-off after 0.5sec to generate a pulse for the controller. I am facing the problem that when I simulate the PIR by connecting L and Lout stripe manually it works fine but when I use the PIR the Shelly does not switch. Anybody has an idea why? Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 5 Members Share Posted July 5 Most likely the PIR has either an electronic switch or a internal circuit which leads neutral potential at its output. Moreover, some PIR devices need a minimum load. You may experience with the above mentioned resistor. In the case this will show no effort, you should add (for test purposes only) a incandescent bulb at the output of the PIR. If this is successful, you may replace the test bulb with a so called „Grundlastelement“. This is offered (amongst others) by ELTAKO. Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Reinhard Posted July 5 Share Posted July 5 Like this? Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 5 Members Share Posted July 5 Not really. Like this: Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Reinhard Posted July 5 Share Posted July 5 Only effect is that the LED stripe is now always off. before it was always on. Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
Members thgoebel Posted July 6 Members Share Posted July 6 With the resistor, the SW input is activated with neutral potential only. Thus, “reverse input“ has to be configured to correct the switching logic. And: The Shelly Mini 1 has to be Gen3, cause the (out-of-stock) Shelly Mini 1 Gen2 has an error in printed circuit board. Does the test bulb light up if PIR is engaged? Quote Translate Revert translation? English (American) Finnish French German Italian Portuguese (European) Spanish Link to comment Share on other sites More sharing options...
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