delay-on-break schematic

[star882]

Does anyone have a schematic for a simple delay-on-break circuit? All the ones I could think of are complicated.
EDIT: it has to run from 5v since that's all that's available from the standby supply. And I'd prefer for it to use common CMOS logic chips.

[wdrzal]

did you consider using a 555 8 DIP IC,or did you want simpler than another IC ? a 556 is a dual timmer version having 14 DIP configuration & a 558 IC is a quad timmer also 14 DIP.As I'm sure you know these are used for timming circuits.

[star882]

How do I use a 555 as a delay-on-break?

[godmod]

star, could you describe what a delay-on-break circuit does? i know a few things in electronics, but some translations are hard.
is this used if you want that eg. the compressor runs for say 1minute after you shut down the pc?

[star882]

Delay-on-break means that when the compressor is turned off, it will wait before allowing a restart. It prevents short cycling.

[wdrzal]

any delay suggest a timer of some sort,here a site that gives basic info for a design.

http://www.uoguelph.ca/~antoon/gadgets/555/555.html


ps: all electronic thermostats use (timed delay on break/before restart) for same reason as you want,to prevent short cycling, hunt up a few designs and reverse engineer to your time requirements as they will be set.;)

a 556 dual timer was used on a solid state siren control for a volunteer fire company,(replaced a mechanical control) but there it was used for (rise time)(fall time)(run time) for 10 hp siren, use basic electronics ,resistance and capacitance to set times.

[SexyMF]

Since the 555's use the RC combination for timings they are not suitable for large delays alone. Large values of R or C are subject to drift which will significantly alter the delay.

To stop short cycling I expect you are wanting at least 5 minutes delay.

This is really were using a uP is better than hardwired CMOS/TTL circuitry. Large delays are no problem inplemented in software.

Though you can use the 555 in conjuction with decade counters like the 4017 to multiply up the output. Cascade several stages of the counters and your good to go.

[star882]

I'll use a 4060 that is reset when the compressor runs (and stop when counted to a certain number) and then require it to count to a number before restarting. If I design it right, the same 4060 might even provide the signal to flash the front panel LED to indicate that it's starting.

[wdrzal]

I used them from 50 milliseconds to 10 minutes, but with desingn modifacations can be used for hours days or weeks for different applications .for many years & I still use these timmers..BTW I was designing fail safe siren controls for fire companies long before pagers and software driven electronics or even 911 centers were the norm. software gives the advantage of programmability, but also the fault of conflicting code or bad code.;)

by adding something like a potter b relay and a magnetic contact the loads you can switch only depend on how large a contact you can find.:D

you'll find as many ways do make a delay as you can find electronic engineers, it depends on cost, programmability(if needed) cycle times & class of components used. And to a large degree what is available and what the designer is used to working with. While I try to stay current much of my basics were studied over 25 years ago. So a design I build may be much different than a new graduate from MIT.

I would struggle with complex code & conflicts as a person just learning to build electronic boards may not even know how to code. But then that may be their expertiese so a software driven design makes sense in that case..

[wdrzal]

Tony Van Roon home page site many great tutorials(electronic design):

http://www.uoguelph.ca/~antoon/

555 IC timing chip:


http://www.uoguelph.ca/~antoon/gadgets/555/555.html

[Xeon th MG Pony]

555s are teh roxurs!

[expansionvalve]

I wish I had the patience and know how to build these circuits, but as I don't I will just go to supplier and buy short cycle timer for din rail, commercial style boxes ftw :)

[wdrzal]

555s are teh roxurs!

Could someone give me the definition of this ????? :shrug: :shrug:

[Xeon th MG Pony]

it is gamer speak as in 555s are the best tiny timer chip in existance for the hobbyist they rock n roll the timer world :)

As you can see I love them, much like the 714 Op Amp for making comperator circuits Can't get the 714s any more so it is the LM310 series and they are great little chips too.

[wdrzal]

how or why wold a gammer use a 555, not a gammer I,cant figure out the need?

[Xeon th MG Pony]

how or why wold a gammer use a 555, not a gammer I,cant figure out the need?


Gamers wouldn't but Old electrical builders do, I use to use them heavily as fail safe circuits and timer delays, then I started to use LM3914-N's as a cascading delay start circuits, simple and effective for sequancing opperations.