2Sets Magnetic Reed Switch Normally Open Closed NC NO Door Alarm Window Security/Magnetic Door Switch/Magnetic Contact Switch/Reed Switch for GPS,Alarm or Other Device,DC 5V 12V 24V Light

Used this on a garage door to determine its state. Was easy to install. It works reliably. The price was right. What else is there?

I purchased this for a Class C Motorhome that had cranky RV steps and were operating in the opposite fashion (ie... in when they needed to be out and vice versa). Electric is not my strong suit, but with a quick you tube video - the switch was installed and the steps were working.

The media could not be loaded. I found that in my bedroom I often forgot to close the window, because I leave the curtains normally closed. Leaving the window open for an extended time, like overnight, is a good way to increase your electricity bill and decrease comfort. So I wanted a warning light that turns on when the window is open and is beside the curtain so that it can be seen. I found these NO and NC switches and also project boxes on amazon, and flashing LED's, battery holders, mini switches, etc, at a hobby place elsewhere online.My handyman put it all together, and put a second warning light on my kitchen window (which has blinds). The pics show the latter one. If the window is closed, the LED is off. If the window is open, even a little bit, the LED flashes, as you can see in the video. The flashing gets more attention and cuts down on battery use too. Apparently, I can leave the window open for a year before the two lithium AA batteries run out. So I do not really need the on/off mini switch. :)Note that when the window is closed, the switches are *offset*. If they were right next to each other, the LED would be on if you opened the window a tiny bit, go off again if you opened it a bit more, and then go on again if you opened it further.

Be aware of using with anything other than very low current. I recommend against powering lights or motors directly without a relay. I initially installed a set to directly switch on LED strips inside a trailer, as others have discussed. (I haven't calculated the current draw but the total length of LED strip is about 20'). As a direct switch, it failed, presumably the magnetic contact fused closed. I repeated a second time to rule out a defective switch and that failed as well. On the final go around I installed a relay to provide power to the LEDs, with the magnetic switch closing the relay coil on the NO terminal, which has a very low current draw. In this configuration the lighting circuit works great and the switch performs as expected. 4 stars for not adequately describing the current limitations in the product specifications. I suspect that's the reason for a lot of negative reviews. The switch works fine, just don't overload it.

I had high hopes for the SpzcdZa Magnetic Reed Switch, but unfortunately, it has been a letdown. I recently installed this switch for a project, and I’ve encountered several issues that make it difficult to recommend.First off, the build quality is subpar. The switch feels flimsy and not very durable, which is concerning given its intended use. It doesn’t seem to have a strong enough magnetic pull, causing inconsistent operation and frequent malfunctions. I’ve had to constantly readjust and troubleshoot to get it to work properly, which has been incredibly frustrating.The installation process was more complicated than anticipated. The instructions were vague and not particularly helpful, leading to a lot of trial and error. Even after getting it set up, the performance was unreliable. The switch fails to consistently detect the magnet, which compromises its functionality for security or automation purposes.Additionally, the adhesive or mounting options provided are inadequate. The switch doesn’t stay in place as needed, resulting in more adjustments and potential damage to surfaces.Overall, the SpzcdZa Magnetic Reed Switch has been a disappointment. Its poor build quality, unreliable performance, and challenging installation make it difficult to justify its use. I would recommend looking for a more reliable and better-designed alternative for your projects.

I have a step down (buck converter) from 12v to 5v feeding this into a relay (keezer – NC for fan when door is closed (controlled and power by a temp relay) and NO when the door is opened for LEDs. When chest freezer door is opened, the fan (if running) stops and LED strip inside turns on.Don’t use these to power an actual device; use a relay for that and this to control the relay.

I installed LED strip lights on the inside frame of a kitchen cabinet. These switches are rated to carry 200 MA and the strings of LED would exceed that so I installed 12 V relays to control the lights. By using the switches with relays I was able to wire them such that opening either door of the two door cabinets would turn on the lights. I installed the switches with double side mounting tape with the switch on the door frame and the magnet on the door. Simple, easy and reliable. Some reviewers complained that the switches failed after a short time. I suspect they had overloaded them with too much current. Mine have been working for months.

These switches do not come with the extra cover to protect the wire connections normally found on similar style switches. Also, the screw terminals are very flimsy and cheaply made. Depending on how much slack you have in the wire it could be tricky to wire up. I used these to set off a siren when the door was opened, the existing wire was cut short by the contractor that did the renovation. It was a little tricky to get it connected so it will last and won’t fall off in a week.