3 ms·
> That means that the lower limit of the supply voltage is about 5V but the upper limit is much less than 40V. That's because the input capacitor is rated at 25
by stephen_g 3y ago
> That means that the lower limit of the supply voltage is about 5V but the upper limit is much less than 40V. That's because the input capacitor is rated at 25V, so I would not suggest running it on more than 20V.
Depends on the type of capacitor but I probably wouldn’t push that past 14-16V, often for ceramics we’ll derate by 50% (specify a capacitor with at least double the voltage rating it will see) since capacitance can drop as voltage increases, depending on the temperature also. Electrolytics (which this looks like) should be fine for 60% or a little more, but 80% as the article suggests is pushing it!
- exmadscientist 3y agoPeople treat electrolytics more gently than their manufacturers intend. Voltage up to and even a bit beyond their rating doesn't bother them; you only need to leave margin for surges/spikes. If not for those, they are usually happy at 100% of rated voltage indefinitely. What kills them is heat. No matter what the source is, internal heating must be managed if they're going to live. (They might still live a very long time, if they're high-end ones.) That means designing carefully around ripple currents. Ceramics in parallel can work magic here.