HPS140i charger voltage

Instruments HPS140 Handheld Pocket Oscilloscope
1

Hi,

I have just purchased a new HPS140 from Maplin Electronics(UK) and placed it on charge using the supplied USB charger lead.

After an hour of charging there was a noticeable smell of ‘hot electronics’ from the top of the HPS140 but its case was not noticeably hot. I decided to measure the off load output voltage of the supplied USB charging lead. The output voltage was 9.91V. 10% high… Not very good for a charger specified as 9V.

I then charged the HPS10 using a high quality regulated 9V mains plug pack and the ‘hot electronics’ smell from the HPS140 was much reduced. It may just be the smell of the charge regulator getting hot on a new PCB ?

Please will you advise me of the acceptable and safe input voltage range for the HPS140 charge socket and is the supplied USB charge lead supposed to produce almost 10V ?

Fraser

2

10V is not a problem, altough the electronics will run a little hotter.

3

My charger voltage is also 9.9volts but I don’t have the hot smell, however my charging light doesn’t extinguish - should it?

4

No, it never turns off. Charge current is limited so that it can safely charge continuously.

5

Ok, many thanks!