View Single Post
Old 11th Feb 2020, 6:08 pm   #11
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,191
Default Re: Was there something odd about Japanese primary cells?

To answer some of the points...

There is no diode in series with the battery. It is connected straight across the output of the rectifier. No current limiting resistor or anything like that either. I guess the current is limited by the (low-ish) difference in voltage between the battery and the output of the mains PSU and the internal resistanve of the battery.

In some cases the smoothing capacitor is connected after the on/off switch. Meaning that if the unit is plugged into the mains and not turned on, the battery will get unsmoothed DC across it. But of course with the unit on the battery gets a much steadier voltage.

As for removing the battery, yes, it was common (and still is) to tell you to remove 'flat' batteries. And I never leave batteries in something I am not going to use for a time. It was more the case of using a unit (say a tape recorder) on batteries as a portable, coming home and plugging it in to listen in the evening. Most people would not think they had to remove the battery to do that. And there are no instructions/warnings on the unit to do it.

I guess (now I know the circuit) I'll just remove the battery if I am using it on the mains.
TonyDuell is online now