I need to delay the switch ON of my converters by a 60secs /90sec/120sec after recpt of a shutdown data thru a 5VDC /100uA input .
The time delay enables hiccup mode of the converters so that the holding charges in the ckt capacitance are neutralized .
I want a very small /economical design.
Designers kindly help...
I wouldn't use 555, instead consider (also 8-pin-DIP) PICAXE-08.
Delay can be set by programming this IC (command WAIT 60 => 60s delay), there is no problem in triggering it on power-on, and input can read transitions from 0-to-1 and from 1-to-0 ..
Cost - $1.
And the most important thing is that there is no dependence on any external components such as capacitors ..