Chris: Is the battery a rechargeable? Have you tried disconnecting the 91K reisstor and measuring the resulting voltage increase? Doesn't make sense to me.
Ralph Cameron EMC Consulting and Suppression of Consumer Electronics (After sale) ----- Original Message ----- From: "Maxwell, Chris" <[email protected]> To: "'EMC-PSTC Internet Forum'" <[email protected]> Sent: Monday, September 25, 2000 11:30 AM Subject: Battery Safety > > All, > > We have inherited a design from a company which we purchased. The product > is a handheld and can be operated from a pair of Alkaline batteries. Inside > the unit, there is a 91 KOhm resistor across the + and - terminals of the > batteries. Since the people who designed the instrument are long gone, some > of my collegues have asked me if this resistor could be a safety feature. > > I can't think of any way this resistor would help the safety of the > instrument. I did read through the safety test report; and I found no > reference to this resistor being required. All it does is provide a > constant drain on the battery (reducing battery life). It has been > suggested to me that some designers put resistors across batteries to reduce > the electrical noise in a product. To me a capacitor would be better for > this because it wouldn't drain the battery while it was filtering. Even so, > isn't a battery the ultimate capacitor? I'm just drawing a blank why anyone > would do this. I'd love to recommend that we pull this resistor out because > it's a pain to solder and it affects battery life. However, I don't want to > sacrifice the safety of the product. > > Anybody want to take a guess at this one? > > Thanks. > > Chris Maxwell, Design Engineer > GN Nettest Optical Division > 6 Rhoads Drive, Building 4 > Utica, NY 13502 > PH: 315-797-4449 > FAX: 315-797-8024 > EMAIL: [email protected] > > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > > > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
