If the battery holder is of the tube type with a spring in the bottom and a flat piece of metal on the top then you can cut a circle the size of the battery from a piece of tape. Make a hole so the + pole on the battery can make contact. Then stick it on the + connector of the battery holder. Best regards, Hekan >From: mazzoni michele >Reply-To: pic microcontroller discussion list >To: PICLIST@MITVMA.MIT.EDU >Subject: Polarity inversion protection >Date: Mon, 8 Nov 1999 05:26:07 -0800 > >Hello List, > >I have realized an alarm for my bycicle using a 12C508. It is powered by >two AA >size alkaline battery. > >I would like to know if there is a simple (and economic!!) solution which >I can use to protect my circuit against polarity inversion during battery >change. >(I know it's a remote possibility, but it exists) > >I thought to use a serie diode, but the voltage drop bring the PIC power >voltage >near the power supply limit of the MCU. > >Thanks. > > >Best regards, >Michele > >_______________________________________________________ >Are you a Techie? Get Your Free Tech Email Address Now! >Many to choose from! Visit http://www.TechEmail.com ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com