sourcingmap Stainless Steel Float Switch for Water Pump Tank Swimming Pool Garden Pond Liquid Water Level Sensor M10 116mm Length

Fonctionne très bien, bonne qualité, bon prix

オーバーフロー水槽とドッキングに使用しました！オーバーフロー水槽でない水槽とドッキングなんでもしもの為に、水位上限でポンプがOFFする様にしました！サイホンの原理でオーバーした水は濾過層に戻り再び水位が下がればポンプがONします！これで安心して部屋で寝れます！

They work. As they repeatedly warn you, they do not handle large loads - I used mine as a pulldown to an arduino pin and they are fine for that. They'd be fine for switching a 20mA LED, piezo buzzer or triggering a transistor, too. More than that and you're probably pushing your luck with the little magnetic reed switch inside. They claim you can drive a *small* relay with one - I wouldn't, personally. If you need that, a ULN2003 can drive the relay and this can drive the ULN2003; problem solved. Mine was NC with the float down. That's of no consequence when using them to trigger arduino inputs, since you decide what on and off mean in software. For some other applications you might need to install them upside down to get them to turn on when water is present and off otherwise.

農業用タンクで使用していましたが一月で壊れました。

Not reliable: 400mA through contacts keeps it from opening when bulb lifts. Smaller sense current of 10mA through contacts is reliable. Added blocking diode + capacitor snubber across contacts and solenoid valve to prevent arcing to no avail. Resistance is still under 1 ohm when closed, so, again, as sensing with low current they work just fine. Don't use this to drive a heavy duty coil relay or solenoid directly. Only as an input to a solid state relay or micro controller. Otherwise, the switch won't open. I suspect it's a 300mA reed switch and they are saying it can be used for up to half an amp. But after 2 hours at 0.4A, it reliable does NOT open when float lifts. Purchased two of these and both have same issue. I now only use them to sense with small current to drive SSR and haven't had an issue.