Timeline for How do I reset NE555 output to LOW when powered on?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Oct 3, 2017 at 0:08 | comment | added | Bimal Poudel | Yes, without the diode, it seems it turns on "again" when pressing the button, as if it is not obeying the push event for turn-off. | |
| Oct 2, 2017 at 10:48 | comment | added | next-hack | Yes, in fact the time constant is very fast (assuming a "0"-Ohm load), but I also like stressing my circuits by quickly turn on/off and see if any erratic behaviors occur. The diode will help in preventing them (provided that the circuit will have an equivalent load resistance much smaller than 100 Ohm, otherwise adding the diode might not bring significant advantages). | |
| Oct 2, 2017 at 10:44 | history | edited | next-hack | CC BY-SA 3.0 |
edited as per Brian Drummond suggestions.
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| Oct 2, 2017 at 10:43 | comment | added | user16324 | It may not be a problem ... I am just one of those very useful idiots when it comes to testing, lol! But the trick is worth knowing. | |
| Oct 2, 2017 at 10:41 | comment | added | next-hack | yes, you're correct, I will edit the schematics, thank you | |
| Oct 2, 2017 at 10:37 | comment | added | user16324 | And if you switch it off and back on, charge stored on C1 holds RESETn high. If that's a problem, a normally reverse biassed diode from C1 to V+ discharges C1 when the power fails. | |
| Oct 2, 2017 at 9:20 | history | edited | next-hack | CC BY-SA 3.0 |
added 223 characters in body
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| Oct 2, 2017 at 8:51 | history | answered | next-hack | CC BY-SA 3.0 |