Maplin IR temperature indicator fault

[Harry Bloomfield]

For those of you who may have purchased one of these (the orange and gray cased one which Maplin are selling for £30), I have found there is a problem when using several different types of AA cells. The unit can seem to work intermitantly, when the trigger is pressed.

This is due to the +ve post on the cell not quite making full contact with the positive terminal of the unit. Basically - the terminal has part of the case plastic on either side of it forming a bit of a shoulder (to prevent reverse polarity insertion of the cells) and if the +ve post of the AA cell doesn't protrude from the cell enough, the unit become appears to be intermitant in operation.

AA Pro-cells are one example which cause the problem along with the cells actually included with the unit at purchase. I actually took one back to Maplin, thinking the units PCB had become intermitant. Maplins tried some new cells with the same result and replaced it with a new item.

[Clint Sharp]

In message , Harry Bloomfield writes

Duracell, known problem with them and poorly designed battery compartments, the 'pip' on the top makes intermittent or no contact because it's either too wide or not tall enough (sometimes both with some really bad battery compartments).

Other makes also suffer but I can't remember which ones I have had problems with off the top of my head.