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???
04/25/10 04:31
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#175355 - Some years ago I built a charger ...
Responding to: ???'s previous message
I've got numerous batteries for my NiCd battery-powered wire-wrap tool, at least one of which, still quite functional, was purchased in 1979. The charger for it is a pretty simple one, though I've never taken it apart to verify that.

For most of my NiCd "problems", including cordless tools in the shop, and I have plenty of 'em, ranging from a drill to a string-trimmer, to a chainsaw, as well as cordless phones, etc, I have a charger that uses a simple CMOS schmidt-trigger oscillator driving a cascaded pair of 4017's, one stage of which fires a MOSFET from a 160-volt supply for a VERY short period of time. That clears out those cilia, and makes it easy to charge them normally afterward.

One Chinese-manufactured cordless phone, a fairly pricey one, has a charger that simply never has worked properly and always required an external charger to "do it right." I've had two such phones, as one was stolen in a burglary, and both were similarly defective, so I rather imagine it's a design flaw.

That HV-pulse charger is not the whole charger, but it does condition the batteries such that their normal charger, with the exception of that Uniden phone, can do its job. My latest Ryobi charger, one that came with a backpack airless paint sprayer, seems to have the ability to recondition seemingly bad batteries, which ability the earlier generation of chargers lacked.

RE


List of 8 messages in thread
TopicAuthorDate
life xtension or restore NICADs            01/01/70 00:00      
   Flashing            01/01/70 00:00      
      I guess this is it            01/01/70 00:00      
         That's one.            01/01/70 00:00      
            I dunno who he is            01/01/70 00:00      
               Stylish            01/01/70 00:00      
   Be kind to your NiCds!            01/01/70 00:00      
   Some years ago I built a charger ...            01/01/70 00:00      

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