Timeline for How To Hold Power ON For Some Time Without Using A Microcontroller or 555?
Current License: CC BY-SA 3.0
6 events
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| Aug 13, 2015 at 3:19 | comment | added | KyranF | @Jimbo here's a tiny little P-channel FET, which would be fine for the output (high current) MOSFET I just added to the schematic, its got a 1V threshold, as soon as you go above 1.5V at the gate it can do 5+ Amps digikey.ca/product-detail/en/SI1401EDH-T1-GE3/… | |
| Aug 13, 2015 at 3:11 | history | edited | KyranF | CC BY-SA 3.0 |
added output part to circuit
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| Aug 13, 2015 at 3:05 | comment | added | KyranF | Hey @Jimbo, 1-2V Vgs is not difficult, there are many shapes and sizes of logic-level MOSFETs. There is a huge difference in Drain-Source current from 2V to 3V, as in, 2V Vgs_th max will pass at least 250uA, 3V will pass many amps. Depends on the FET of course, but that's normal - A very small window of voltage after the threshold. And how did you intend to power the system then, if you weren't already going to need a 3V battery? You said you will need to provide ~3V to the load, so I thought why not power the system with 3V too. I havent shown in, but you'll need another FET. Let me add that | |
| Aug 13, 2015 at 0:47 | comment | added | Jimbo | My first thought is, I'd love to know where to find a MOSFET with 1V Vgs_th!! That would pass more than mA current, I mean... (There's a limit as to how many components I can string together and still stay in the housing I have planned. And that's assuming I can even find a 3V battery that will source it!!) | |
| Aug 11, 2015 at 6:36 | history | edited | KyranF | CC BY-SA 3.0 |
added 161 characters in body
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| Aug 11, 2015 at 6:29 | history | answered | KyranF | CC BY-SA 3.0 |