Temporized..

[MaXiZ]

Is there a cricuit that when i "click" on a switch it give an impulse
for certain number of second that i can set on that circuit?
I hope to get explained correctly.. I'm italian.. sorry!

[peranders]

If you are going to do it yourself, just check LM555.

http://www.national.com/ds/LM/LM555.pdf

Look at page 7, figure 1.

[MaXiZ]

????
I need this:
dc Source=>circuit=>12v lamp (for example)
......................||
.....................\ /
..................Trigger

With a single click trigger (like the reset of pc) that give an impulse to the circuit it (the circuit) should give current to the lamp for a certain number of second that i can set always on that circuit...

[kelticwizard]

I think you might be able to use a 555 chip configured as a "one-shot". I think that might work.

Two questions:

A) How much power will the device you are powering need? In other words, is it a low power thing, like half a watt, or a high power thing, like 5 watts, 10 watts, or 100 watts? I am trying to figure out if you can use a chip alone or need a more complex circuit.

B) When you hit the trigger, did you plan on the power being on for one second, five seconds, five minutes, or an hour or more? It is important to know so we can plan the component values for the circuit. If you plan to make it adjustable, please give me a range of times. For example, do you want to be able to adjust it to work from between 5 seconds adjustable up to 120 seconds, or what?

Again, this is important so we can select component values.

[MaXiZ]

the power needed is about 50W..
Maybe that the 555 act on a relay..?
And a question.. the triger where should be connected (over at the 555)?
I need the circuit run for 1 minute as max time...

[kelticwizard]

http://www.national.com/ds/LM/LM555.pdf


Well, judging by the values in Page 7, Fig 3, for sixty seconds of ON you need either 1 megaohm, (1 million ohm) resistor and a 75 microfarad capacitor, (uF), or a 10 megaohm, (10 million ohms) resistor and a 7.5 microfarad, (uF) capacitor.

The resistor can be made adjustable. So if you use a 75 uF capacitor, you can hook use a 1 M ohm potentiometer, plus a 100 K ohm fixed resistor in series with the potentiometer. Such a setup will give you a resistance adjustable from 100 K ohm up to 1.1M ohm, and an ON interval equivalent adjustable from about 6 seconds to a little over 60 seconds.

Is that what you are looking for?

The trigger should be connected between pin 2 and ground, I believe. It should be as you say, just a momentary switch-NOT one that you when pressed will switch completely to ground until you press it again.

Hooking up to a relay sounds like the way to go. However, I do not have much experience with them, so your choice is probably as good as mine. there are also SCR's and SPDT, but again I haven't used them.

It seems to me that you should Email a moderator to change the title of this thread. There is a lot of expertise on this forum, including a lot of people with more experience in this sort of circuit than I.

Might I sugest that you Email a moderator-perhaps Peranders-and get him to change the title of this thread to "High Power Interval Timer-Design Help Please", or something similar?

I think there is a lot of people on this forum who would help you, but "Temporized" is a title that sounds too vague, and they probably never read the thread.

Try a title change-the Moderator will be glad to do it for you, and I think you will get more help from the other members of the forum who have more experience designing this type of circuit.

[kelticwizard]

While you are at it, can you please tell us:
A) Exactly what it is you plan to power, (is it really a lamp, or something else?)

B) Is it AC or DC power that we are dealing with

C) For the sake of finding a relay, what is the maximum voltage and maximum current we are dealing with here?

Whew! Just checked Mouser, www.mouser.com High power relays look like they cost a fair amount, like $20 or more.

[MaXiZ]

It's dc, the relay should be 12v and 1-2A as maximum..
I need to power a car pump... well.. i don't know the right word to define it.. The pump that wash the front glass of the car..
Well.. I don't know what's the word.. I'm Italian..

[Carondimonio]

Hi MaXiZ,

there are programmable relays on the market which can do exactly what you need and much more:

programmable relays

Cheers,

Bruno

[davesaudio]

I think a minute is way too much , you may empty your jug.

A 555 operating a relay is fine for this.

You need to ensure your relay energizing current does not exceed the 555s limits.
-otherwise another transistor/mosfet required.

Bet you can find a circuit like this using google
555 one shot timer relay etc