I am looking for a 555 timer / latch circuit

[555 timer fan]

I am looking for a multistage 555 timer / latch circuit that turns on multiple 120v ac outlets in an individually adjustable timed sequence. As each outlet turns on the previous ones stay on and then at the end circuit locks the outlets on.

 

[carbonzit]

Sounds like you just need individual delay timers for each outlet, independently adjustable.

Are you going to start all these at the same time? You could just use separate delay timers, all triggered from the same switch or signal. No need to make a "multistage" timer. (In other words, each timer would have an adjustable delay time, all starting from T=0 when the switch is thrown. To make them sequential, simply arrange the delay times from shorter to longer.)

Not sure what you mean by "at the end circuit locks the outlets on"; with the scheme I just described, the outlets will stay on once the delays elapse.

 

[555 timer fan]

Need schamatic

Thank you carbonzit for the idea. I do need a circuit diagram. Would the circuit use 555's?

 

[carbonzit]

Well, first let's make sure we know what you actually want. Will what I described above work for you?

How are you going to start the timers: a manual switch? a signal from a microprocessor or something else?

How much current (in amps) will each outlet be required to handle? Is this 120 or 240 volts?

You need to get the details of how it's going to work before you can create a circuit.

 

[Reloadron]

There are a few ways to go about what you want to do. However, per carbonzit there are a few additional questions. You mention wanting to switch 120 VAC but don't mention the current? That is important. You also mention:

latch circuit that turns on multiple 120v ac outlets in an individually adjustable timed sequence.

From this I assume that each step in the sequence must have an adjustable time delay? If that is not necessary and the timing can be the same then the circuit is less complex, however, if each stage has a specific time before the next then it gets a little more complex.

What exactly, in detail are you wanting to do?

<EDIT> I forgot to ask what you wanted for timing periods? 1/2 second, 1 second, 5 seconds, what sort of times were you looking at? </EDIT>

Ron

 

[555 timer fan]

Q and A's

Hello Reloadron and Carbonzit

I want to thank carbonzit for the idea of the independently adjustable timers
I was thinking of using independently adjustable timer relays, all of them triggered at the
same time (T=0), but I have not investigated this yet. I am going to let the two of you
who know what they are doing come up with the design. Now to answer both of yours questions


First & Second Answers:

I admit I had forgotten about the current ratings, all of them are at 120v ac.

Outlet #1 (Cable modem, 0.3 amps) comes on immediately at power up.
Outlet #2 (Vonage Adapter, 0.8 amps, Home Phone service) turns on 50 seconds after power up.
Outlet #3 (Router, 0.11 amps) turns on 110 seconds after power up.
Optional Outlet #4 (A possible 4th device not yet thought of) turns on 130 seconds after power up.

So I think it would be easier just to round the current loads to 1 amp each.
Then when delays are done all outlets stay on!


Third Answer:

I have yet to think of a triggering procedure.


Unasked Question: Sounds pretty simple, why do you need this?

Unasked Answer:

Well if it was just me I wouldn't bother, but I have found that if I lose power and then when the power is restored I have to power up the cable modem, the Vonage adapter and the router in the above order and timing. If they are powered up out of order then the Vonage adapter will not communicate with the cable modem (no home phone). The router cannot talk with the Vonage adapter (no internet on computers). When it happens when I am at work, I have gotten a call from my wife has asking what she should do. I told her to unplug the modem's power plug and when I got home I found she unscrewed the coax cable to the modem instead.
God knows I love her but I do not want her, or the kids (ugh), anywhere near these devices again.

I want to take this time to say thank you to the both of you for any help.

555 timer fan

 

[carbonzit]

I kind of suspected you had in mind something like this. I still think that separate timers all started at the same time is the easiest way to implement this. Set each timer for the appropriate time, and they'll fall right into line. Much simpler than cascading the timers (timer 1 triggers timer 2 triggers ...).

Your power requirements are quite modest and should be easily handled by the right devices (like relays).

 

[Reloadron]

You can go with a pretty much off the shelf solution if you want using "on delay" timers similar to these or you can roll your own. The off the shelf run about $50 each but much cheaper versions are out there. When power is applied each turns on after a preset delay. No muss no fuss turn key solution.

If you choose to roll your own you can just build a series of 555 timers where each provides a delay on. There are a few ways to go about doing it but for a delay on each stage would be a two stage where the first one shot triggers a second. Attached is an image of a two stage delay on timer using 555s or actually a 556. Since you want the outputs to remain ON you would need to drive a latch circuit of sorts then drive a SSR circuit.

Another method attached is a sequential method where each timer triggers the next and the time for each is set by the R1 * C1 network for each timer. This circuit shows the latches. You only need 4 stages as I read things.

Finally another viable solution might be just to use a UPS back up. Your demand is low and a good UPS would afford hours of uninterrupted power. Actually that would be my choice. For extended power outages an external SLA battery could be added. Personally I have my modem and a few wireless and wired routers configured this way as well as the several computers on the network. During a power outage nothing needs reset.

<Edit> Before I forget totally, there is another 555 variation I have seen in this forum where a single 555 is used as a one shot with an added RC timing network. It could function much like the two stage 555 circuit I posted but using a single 555 design. </EDIT>

Ron

 

[555 timer fan]

Thank yous

Thank you Carbonzit and Reloadron for all your help with this. I have an ES750 APC UPS but it is heavily taxed with 2 CRT monitors and 2 system units everything else is run through the surge suppressor side. Using a second UPS was to be my first choice but money being tight I thought I would go with a simple electronic circuit or something (relays) to control the outlets (modems and router). Maybe if (or when) money isn't as tight I might invest in a second UPS with each computer/monitor being on its own with putting the modems and router on the battery backup side.

 

[MrDEB]

I am thinking perhaps a 555 (an output clock every 25 seconds)triggering a 4017. Outputs connected to opticouplers/SCR's to hold ON the opticoupliers. Triacs to control the 120v
Easy way would be a microcontroller.
The SCR's would be controlling DC current so they would stay ON after triggering.