Hello,
I want to made a latching reed switch, but many time I tried the result not consistence. I do not have the tutorial.
Please share how to made latching reed switch.
regards
If a suggestion is permitted, find a magnet that will close a reed switch with a coil around it. Position the magneto to just before the point the switch closes.
When the coil is energized the switch will close (if you have enough turns and amps in the coil). The switch should remain closed after the current is removed. If it does not stay latched then you need to reposition the magnet and try again.
To unlatch the switch, send a reverse current through the coil for a short period, 0.1 second should be enough. If a reverse current pulse does not cause the switch to "unlatch" you should increase the amps and turns and try again, repositioning the magnet if necessary.
Hello,
Actually the device is no need a coil, just the magnet polarity to make the latch or unlatch. The small permanent magnet is sticked to reed switch and to operate just give the other magnet to make latch or unlatch.
So, does the stuck-on magnet keep the reed contacts closed when the other magnet is removed?
Are you having difficulty keeping them closed or making them open?
Lets say, the reed in vertically position and then a permanent magnet move passing from top to bottom the contact state is latching ON. Vice versa if a permanent magnet move passing from bottom to top the contact state is keep OFF. The example application used for level control, the switch condition still run even though have power failure.
I'm interested in this as well, as I'm trying to make something similar (the few I've found commercially available are pricey). I agree that a coil isn't needed. The concept of a bistable reed switch is that when it is closed (say via N magnetic field), it stays closed until it encounters a S magnetic field, after which is stays open until it again encounters a N magnetic field.
@hilologic - I think part of the issue in what you have in your image is that the magnet is immediately on the switch, so I assume that it probably stays in whatever position the magnetic field gives it naturally.