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| Thread ID: 119232 | 2011-07-12 06:22:00 | Adding battery backup to a DC power supply. | pine-o-cleen (2955) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1216300 | 2011-07-12 06:22:00 | Is this a relatively simple process? I've just received a numitron (low voltage nixie tube) clock that runs on 5v dc, and of course as soon as it loses power, it loses the time. I've got it running on a USB output at the moment. So I was thinking a 5v power supply with a battery backup addition. How would I go about this? |
pine-o-cleen (2955) | ||
| 1216301 | 2011-07-12 12:50:00 | If the display is not voltage critical and can run on just over 4 volts, a five volt battery connected via silicon diode could possibly do it. The diode would be reverse biased when the power was on (because the dc supply is bound to be more than 5 volts) but as soon as the power failed the diode would be forward bised and run the clock until normal power was restored. Normal silicon diodes bias on at 0.6 volts or so but you can get special types that have a lower threshold. Prospective current drain would determine the size of the battery, and it might be easier to just backup the clock electronics but not the display, or just reset it after the occasional outage! Cheers Billy 8-{) |
Billy T (70) | ||
| 1216302 | 2011-07-13 06:42:00 | Hmm, so not so simple for me. I guess resetting it after power outage would be easier. |
pine-o-cleen (2955) | ||
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