NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
RES: Recharging Compas Magnet
From: Jos� Otavio O. de Almeida
Date: 2004 Jun 20, 15:55 -0300
From: Jos� Otavio O. de Almeida
Date: 2004 Jun 20, 15:55 -0300
You can recover the compass by applying a strong manetic field on it. You can do that by winding a coil around the compass, and applying DC (continuous current) on it. The coil plane should be perpendicular to the plane of rotation of the compass. The compass "needle" should be left free to rotate, so that when you apply dc to the coil, it will align itself to the magnetic field generated. Try, say about 50 turns of AWG 24 or 28 wire, and apply 12v DC from a car battery. The contact should be brief, less then a second, as the current will be very high, almost a short circuit. If you leave it connected it will generate a lot of heat and burn.Just scratch the contact a few times, that shoud do it. Jos? Almeida. -----Mensagem original----- De: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]Em nome de Zvi Doron Enviada em: domingo, 20 de junho de 2004 04:47 Para: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Assunto: Recharging Compas Magnet Hello, I have a small emergency field compass that was kept unused in a pocket on my mountain bike for the last 10 years. I took it out recently and discovered it had become very sluggish. I suspect that the magnet under the compass card has lost much of its power and canot overcome the friction between the compass card and the needle it floats on. I cannot open it to get to the needle and clean its tip. Is there a way to recharge the magnet? I tried placing the compass overnight on magnetized objects like my phone handset or a large screwdriver but I suspect I need a stronger source of magnetic field. A 220V wire leading to an operating house appliance perhaps? Any advice would be much appreciated.