On Mon, Feb 14, 2011 at 3:51 PM, Phil Kett <[email protected]> wrote:
> > > On 14/02/2011 21:23, Tony Firshman wrote: > >> Plastic wrote, on 14/Feb/11 20:50 | Feb14: >> >>> On Mon, Feb 14, 2011 at 2:09 PM, Tony Firshman<[email protected]> >>> wrote: >>> >>> >>>> >>>> On 14 Feb 2011, at 20:01, Plastic<[email protected]> wrote: >>>> <snip> >>>> >>>>> >>>>>>>> Is the CR2032 man enough though? >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> The CR2032 is 3V 235ma, and on this card would need to be replaced >>>>>>> >>>>>> every >>>> >>>>> three years or so, which would be a simple "pop a new one in" >>>>>>> >>>>>> operation... >>>> >>>>> The 40LF220 had a lower current capacity but was designed for a long >>>>>>> shelf >>>>>>> life of ten years, hence the bulk. So yes, the CR2032 truly fits this >>>>>>> application. >>>>>>> >>>>>>> The format is standard for battery backed clocks on PCs, but was >>>>>>> quite >>>>>>> >>>>>> new >>>> >>>>> in the late 80s. >>>>>>> >>>>>>> I will look at current costs for getting a batch of 100 of these >>>>>>> tiny, >>>>>>> single layer PCBs made. >>>>>>> >>>>>>> Couldn't the card have a battery socket so that only the battery need >>>>>>> >>>>>> be >>>> >>>>> replaced? >>>>>> >>>>>> ( ... and why are you not yet living Texas time - it is 2am (8-)# ) >>>>>> >>>>> >>>>> >>>>> That is exactly what I was describing ;) A simple adaptor card to a >>>>> >>>> CR2032 >>>> >>>>> socket, and a CR2032 battery. >>>>> >>>> Ah sorry. >>>> 3 years though seems a mite short. I wonder if there is a more beefier >>>> battery that is thin enough - or maybe a chargeable one? >>>> >>>> >>> There is, but it has 50% higher capacity and costs $12 instead of $0.99 >>> at >>> the supermarket. I said three years as a minimum. It's quite possible >>> that >>> it would last 5-6-7 years - I'm just being very conservative. Also, the >>> CR2032socket in bulk is under $1, but the socket for the CR2045 is $7.80 >>> in >>> bulk. >>> >>> I think people will happily pay $15-20 for a 3-5 year battery change at >>> 99p >>> than pay $25-$30 for an extra couple of years. Also, changing the CR2032 >>> batteries is so easy... 15 seconds, including removing and re-inserting >>> the >>> card. >>> >>> Yes - in that case the 2032 makes sense. >> It is a pity the PC has stadardised now on the low capacity >> non-rechargeable. In the old days they used a Minerva like NiCad pack that >> lasted for yonks. >> >> > These NiCad packs are not good in old computers - I've seen far too many > amigas destroyed by acid from leaky rechargeables! > > GC and SGC are scarce enough these days as it is - imagine how bad it would > be if they'd had a rechargeable battery on them.... Okay, I have looked at the parts, PCB design and got a couple of quotes for PCB manufacture. As a rough guide, it looks like the retail price from a trader would be around $20 (€14.83, £12.50) to $25 (€18.54, £15.60) if I made 100. Lead free, gold contacts, includes quality CR2032 battery. Requires soldering four pins to install (or ship your card off for a nominal fee if you're not confident to do this). You may need to change the battery out once every 5 years or so. You can buy CR2032 batteries at your local supermarket. What is the interest in this part? Dave _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
