Discussion in 'The Projects Forum' started by ht systems, Aug 21, 2011.
can i use an ac voltage as an input to 555 circuit ?
thank you , i guess i have to try it
The powersupply of the 555 MUST be DC.
What input do you mean?
The trigger input may NOT go negative and above the DC voltage of the powersupply.
Well, no - it can't use AC directly as an input, as AC implies that the signal goes above and below the 0v reference; the negative voltage would burn up the 555 timer.
It might use rippled DC input, as long as the rippled DC did not exceed the limits of the timers' power supply rails.
Rippled DC can resemble AC (as a sine wave), but isn't centered around the 0v reference.
Good point, wookie. I missed that. Or did I assume ht knew that? It's so hard to guess the intellectual level of a person when you've only seen him make one sentence.
Always assume the worst. And ask for a schematic.
Could use clipping diodes to VCC & GND with current limiting, also capacitive couple input.
Sometimes I feel like I am the only person who can see this thread.