HP 97 VERY hot charger

[Katie Wasserman]

(10-16-2014 03:30 AM)brouhaha Wrote:  

(10-16-2014 02:10 AM)Katie Wasserman Wrote:  the charger is not current limited so it's getting really hot becasue it's looking at almost a dead short

Actually the charger IS current limited. UL will not list it otherwise. However, it is current limited by the design of the transformer, not by additional components.

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You're right from a safety standpoint, of course, but I was trying to explain why it got so hot. I meant that the circuit design does not limit the charging current, so it can/will overcharge nicad cells in a pack if some of the other ones have shorted out. Having 4 good cells in the pack is what prevents the transformer from getting too hot normally.