555 and relay

[swilsonNC]

Ok thanks I will give this one a try and see if it works like I am expecting. I am assuming I can change R2 and C4 to my needs. Thanks

 

[swilsonNC]

Ok, I see that one repeats even if V2 is removed. I want V2 removal to stop the timers completely and leave V1 as is. Then 10 or 30 seconds or 2 minutes later (examples of just any time) power is applied at V2 and it starts the timer again. If timer goes to past 3 seconds then out2 triggers relay. If V2 loses voltage at 3 seconds (before out2 has time to trigger) then the timers stop the cycle again. Rinse and repeat. Only repeating I want it to do is if I make it go again by pushing a button. I will play with this circuit and see if I can figure it out but if you come up with something different let me know. BTW all of these circuits are great designs but just not what I need.

Hmm I guess its a 5 sec delay then a 1 sec one shot that will be started over when v2 gets voltage again. Interuptable if v2 loses voltage before the one shot.

 

[alec_t]

I'm still not sure what timing you want. At one point you said "I should be able to trigger it over and over by keeping the voltage on V2", so that's what I designed the circuit to do; but now you're saying "Only repeating I want it to do is if I make it go again by pushing a button.".
You also said you wanted timer1 to run for 5 secs before out2 triggers the relay but now you're saying "If timer goes to past 3 seconds then out2 triggers relay."
Can you draw and post a time-line of your requirements?

 

[swilsonNC]

Ok let me see if this will work. Forgive me please since I am semi new at designing circuits and this timeline probably sucks but here you go.

View attachment 63315

If voltage is dropped while Timer1 is counting before it gets to 5 seconds nothing else happens. Once Timer2 starts its output of 1 second to the relay it needs to complete that 1 sec no matter what to keep from hammering the relay since you will lose voltage at V2 when the relay on the output of the timers energizes.

So V1 always has voltage
V2 only has voltage if ECM sees a "condition" and will keep voltage until system is reset.
Once V2 loses voltage timer1 needs to stop and not output any further. If timer2 gets its trigger (low from timer1) then it goes a complete 1 sec at 14V no matter if trigger is there or not.
Timers need to sit and wait for V2 voltage at any time which starts the timers and resets the system via the relay at output.

 

[alec_t]

That's much clearer. Try the attached Mk3 version. It now includes a pull-up transistor to prevent timer 2 being triggered when V2 is low. In this sim timer1 period is ~ 5.2 secs. Fingers crossed.....

 

[swilsonNC]

Ok will try that one later. Will have to run to the shack and get a PNP transistor as I don't have one here currently.

I actually soldered an earlier prototype the other day, I think the one I had in post #9. Other than adding a cap on CV1 it seems to work pretty good hooked up on the truck. If this one works better I will for sure solder it up too. Love playing with this stuff just wish I knew more about the designing part right now. Thanks