Timeline for Pumping a few amperes for 100 µsec
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
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| Aug 18 at 2:29 | comment | added | MicroservicesOnDDD | @Kubahasn'tforgottenMonica -- The Joule-Thief uses an inductor (coupled inductor = Power inductor + sense winding), Both the Buck or the Boost (or the inverting) JT are current sources. You must use the inverting topology to charge the cap initially, else the inrush current defaults to being a voltage source. | |
| Aug 13 at 10:48 | comment | added | Kuba hasn't forgotten Monica | @Ktc A solution just using a Cap would be probably much more easy to manage. Charging a capacitor from a voltage source always loses 50% of the energy in the series resistance of the circuit. To charge a capacitor efficiently, you need a current source, and that current source must be efficient. Hence the need for an inductor. It is impossible to efficiently charge capacitors without using inductors. | |
| Aug 12 at 16:36 | comment | added | MicroservicesOnDDD | For people who end up here, there are other Joule-Thief type circuits that would also work. What follows highlights just one of them. Here is a Buck Joule-Thief that could also be used instead of the standard one. Also... After the Joule-Thief (Buck or Boost, any), you can add some filtering and/or an LDO to efficiently produce the desired power output waveform. | |
| Apr 13, 2012 at 13:01 | comment | added | clabacchio | @Ktc the problem is that you (presumably) have a fixed load, so the way to give it a big current is to cause a big voltage; that is the work of the Joule thief. The other chance, as Steven says, is that store the charge in a capacitor and then switch it. But depending on the LED you are using, the voltage may not be sufficient | |
| Apr 13, 2012 at 11:06 | comment | added | Jason S | maybe, but I don't see how you would ever regulate current using just capacitors. | |
| Apr 13, 2012 at 9:26 | comment | added | Ktc | Interesting.. A solution just using a Cap would be probably much more easy to manage. | |
| Apr 13, 2012 at 7:45 | history | answered | clabacchio | CC BY-SA 3.0 |