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  #11  
Old 18th August 2019, 09:06 PM
JulioF JulioF is offline
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1.25 A is 1250 mA, not 12500 mA. The Jessops secondary seems to have several taps at different voltages.

You need a replacement adapter that gives 9 V at 0.85 A (850 mA) or higher current; should not be hard to find one. Be careful with the connector tyoe and polarity. Check it in the Jessops model, polarity is usually written in the plate.

Last edited by JulioF; 18th August 2019 at 09:11 PM.
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  #12  
Old 18th August 2019, 09:23 PM
Mike O'Pray Mike O'Pray is offline
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Thanks Julio for pointing out my typing error. Yes it is 1250mA. In fact in an earlier post I explained that I had solved the problem. The new adaptor delivers 1000mA at 9v so is fine.

I am now trying to ask questions that will expand my electrical knowledge.

The Jessops operated on 1250mA at all voltages from my understanding of the information on the label and that appears to be unusual for modern adaptors. Most I came across operate at only 650mA at 9v but driving old fashioned lightboxes is not the usual task that is asked of adaptors these days

Mike
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  #13  
Old 18th August 2019, 09:34 PM
JohnX JohnX is offline
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The battery's are a variable with regard to their current output.
They're all different, alkaline are different to acid are different to rechargeable, they vary also by manufacturer, by quality and by the performance curve of delivery.
The rating is detailed on the battery itself, basically, the higher the mah rating the longer the battery will last.
This is irrelevant to rechargeable battery's unless you want to minimize the frequency you have to recharge, there are some rechargeable cells with big ratings that will out run alkalines even at 1.2v, so its not a simple b/w issue.
The failed adapter gives 1250ma at 12v, its probably higher at the lower voltages but they have detailed worse case scenario of 12v.
Clearly this adapter has some clear water between it and the 800ma requirements of the lightbox, which is the better place to be tbh.
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  #14  
Old 19th August 2019, 12:51 PM
Mike O'Pray Mike O'Pray is offline
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Thanks John for the explanation. It sounds as if these days the rechargeables have moved on so much that the best of them will outperform the alkalines. I still have a few old Nicads and while they worked, their lives were very limited

Mike
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