lopburi3 13810 Posted December 30, 2022 Share Posted December 30, 2022 Quick check of Lazada only shows on at night off at dawn type switch and most circuit box type are motion only. Have bath where would prefer not to run wire and looking for way to use on/off wall box fan control to sense light on and off to turn fan on during time light is on. Seems easy but all sensors appear to only operate on with dark. Any ideas/source/laugh. Quote Link to post Share on other sites More sharing options...
degrub 233 Posted December 30, 2022 Share Posted December 30, 2022 If i remember my relay logic correctly, you just need an interposing relay with a normally closed contact to feed the power to the fan motor. The light detector module output provides the current to the relay coil. Match the current type (AC/DC) and voltage level provided by the light detector module. If the light detector output is too low, use another relay to switch a DC or AC power source that is fed to the interposing relay. 1 Quote Link to post Share on other sites More sharing options...
lopburi3 13810 Posted December 30, 2022 Author Share Posted December 30, 2022 6 minutes ago, degrub said: If i remember my relay logic correctly, you just need an interposing relay with a normally closed contact to feed the power to the fan motor. The light detector module output provides the current to the relay coil. Match the current type (AC/DC) and voltage level provided by the light detector module. If the light detector output is too low, use another relay to switch a DC or AC power source that is fed to the interposing relay. That sounds right sensor power on (dark) will open contacts external relay cutting power fan. Not pretty but should work. Thanks. Quote Link to post Share on other sites More sharing options...
Crossy 46048 Posted December 30, 2022 Share Posted December 30, 2022 Alternatively, assuming you can get the dark switch apart, many of them have a change-over relay anyway, you should just be able to move the output wire to the normally closed contact. Quote Link to post Share on other sites More sharing options...
lopburi3 13810 Posted December 30, 2022 Author Share Posted December 30, 2022 3 minutes ago, Crossy said: Alternatively, assuming you can get the dark switch apart, many of them have a change-over relay anyway, you should just be able to move the output wire to the normally closed contact. Was thinking that - and had hope one might actually have an external wire to do so - but they all seem to be sealed box units and likely beyond my current eyesight/solder abilities. 🧑🦯 1 Quote Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.