Hi everyone. I sure hope I'm not posting a question that has already been answered a billion times but here goes.
My plans are to build an on/off timer that has a variable "on" time as well as a variable "off" time. On times would be selected from ¼ sec, ½ sec, 1 sec, 2sec and 4 seconds (I think this can be accomplished using a voltage divider network and a rotary selector switch). Off time intervals would be selected from 1 sec, 2sec, 4sec, 6sec, 8sec and 10 seconds (same voltage divider network). When the timer is on it will supply +4.5VDC and when the timer is off it will of course supply zero. I am sure this can be done with a PIC, but I'd rather not go that route. I think this can be accomplished using one or two 555 timers, but I just can't wrap my head around it. I have experience building circuits off of a schematic, but when it comes to the design aspects, I am rather limited.
As for input power I have a 120VAC power supply supplying +24VDC (3A max) that I would like to use and then step the voltage down to the desired pulsing output voltage before entering the timer circuit.
I am really hoping someone can point me in the right direction here. If it sounds like I am asking someone to just plop a schematic I do apologize. Not asking for a hand out, just need to be pointed in the right direction. Thanks!
My plans are to build an on/off timer that has a variable "on" time as well as a variable "off" time. On times would be selected from ¼ sec, ½ sec, 1 sec, 2sec and 4 seconds (I think this can be accomplished using a voltage divider network and a rotary selector switch). Off time intervals would be selected from 1 sec, 2sec, 4sec, 6sec, 8sec and 10 seconds (same voltage divider network). When the timer is on it will supply +4.5VDC and when the timer is off it will of course supply zero. I am sure this can be done with a PIC, but I'd rather not go that route. I think this can be accomplished using one or two 555 timers, but I just can't wrap my head around it. I have experience building circuits off of a schematic, but when it comes to the design aspects, I am rather limited.
As for input power I have a 120VAC power supply supplying +24VDC (3A max) that I would like to use and then step the voltage down to the desired pulsing output voltage before entering the timer circuit.
I am really hoping someone can point me in the right direction here. If it sounds like I am asking someone to just plop a schematic I do apologize. Not asking for a hand out, just need to be pointed in the right direction. Thanks!
