Timeline for Powering a self-drive piezo buzzer with capacitors?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 14, 2016 at 19:51 | comment | added | Spehro 'speff' Pefhany | 45 10,000uF caps might be a bit pricey too. | |
| Jun 14, 2016 at 18:42 | vote | accept | cg14 | ||
| Jun 14, 2016 at 18:36 | comment | added | cg14 | Understood (I more or less included it in case some one else wanted to see what you gave in more detail.) Instead of using something that falls into the super capacitor range, I am assuming I could potentially use a capacitor array instead? Super capacitors tend to run a little expensive. | |
| Jun 14, 2016 at 18:33 | comment | added | Spehro 'speff' Pefhany | I'm not going to slog through your math, but yes a large capacitor in the 0.1-1F range that does not have too much internal resistance to supply the required current. | |
| Jun 14, 2016 at 18:32 | comment | added | cg14 | Additionally, assuming this is correct just a relatively large capacitor is needed in order to make this configuration work? | |
| Jun 14, 2016 at 18:30 | comment | added | cg14 | I actually had just worked the math and I got something similar: i = 10mA, v = 5v; P = i*v = .05 W; E = P * (time_on) = P * 20s = 1 J; E = 1/2 * C * V^2; C = 0.1 F. Vf = Vi(e^-t/(tau)); R = -20s /ln (Vf/Vi)/ C = 493 ohm. Is this the correct way to approach deriving Tau ? | |
| Jun 14, 2016 at 18:10 | history | answered | Spehro 'speff' Pefhany | CC BY-SA 3.0 |