New and need help with the name of a part I am in search of..

[chrisk]

Im looking for a controller or module that when a switch is activated it will only send out a signal or voltage for a few seconds and will not continue sending signal or voltage till the switch is released or reset.

Does that make sence?

I was looking at this but still need to have something not keep sending voltage with the switch on.
https://www.amazon.com/gp/product/B...ue&ref_=ox_sc_act_title_1&smid=A30QSGOJR8LMXA


Thanks for the help.
Chris

 

[chemelec]

Depends on What the signal needs to be?
Just a single Capacitor will send a Very Short Signal as power is applied to it.

In conjunction with triggering a 555 timer, it can send a signal of few micro-seconds to 10 seconds or more.

 

[chrisk]

It needs to be 12v DC in and 12v DC out.

 

[chemelec]

If the 555 is operating at 12 Volts, than your output will be close to 12 Volts.
Or the 555 could drive a Mosfet to give Higher Current and maintain 12 Volts out.

 

[spec]

Hello Chrisk,

I was looking at those modules just the other day, but do not have the circuit. As far as I can tell you put say 12V power on them then after a delay they switch over. If that is true and the relay is a change over type it should do your job well. What load are you switching into. We need to know what current will be switched. Tell us as much as you can about your application. Pictures, circuits, specifications are good as was your link.

 

[chrisk]

Lets say I have a spark plug hooked up to a push button. Forget the coil and stuff to make the spark.

Push and hold the button and it sparks for only 2 seconds and no more if the button is held down longer.

Release the button and press it again. Spark for 2 seconds only.

 

[KeepItSimpleStupid]

What's supposed to happen when you rapidly push and release the button?

 

[chrisk]

That won't happen and it will also have a delay.

I just need to know what to use to supply voltage for only a few seconds when the button / switch is held down.

 

[jamie_s]

a spark plug wont spark for two seconds as you need a dwell period to charge the coil, then drop power to the coil to induce the spark. you then have to repeatedly charge and discharge the coil to keep it sparking for the two second period,
how many sparks do you need?
be easiest using a PIC micro

 

[chrisk]

The spark plug thing was just a example.
I have a high volt coil that can only run a few seconds.
Image from http://g01.a.alicdn.com/kf/HTB1laOx...ator-super-arc-pulse-ignition-coil-module.jpg.

If I supply the coil with switched 12v it will output the spark. If the switch it held for longer then a few seconds the coil will burn out.

That's where I need something to control the switched output. And I don't know what to use.

Thanks
Chris

 

[spec]

Hi Chris,

I did a diagram of an approach for you, before the above posts came in.

It is based on my interpretation of what you initially said and also my assumptions about the timer module function. Please don't treat it as a final design because there are a few things to confirm before we can reach that stage. Instead treat it as notional and for discussion. The diagram shows the Timer Module in the REMOTE LOCATION, of course there is no reason why it could not be in the LOCAL LOCATION.

From the picture on the link you posted, you can see that the relay can handle 10A, but it could be that the igniter takes more current than 10A, especially when starting up so that is one area to watch.

One final point: would you be able/prepared to build a simple circuit from scratch? If so we, could do pretty much anything within reason.

The arrangement shown in the attachment works like this:

(1) With the switch open '12V PULSE' will be at 0V.

(2) When the switch is pressed '12V PULSE' will immediately jump to +12V.

(3) After a time, that you can set with a variable potentiometer on the Timer Module, '12V PULSE' will return to 0V.

(4) Whenever the switch is open '12V PULSE' will always go to 0V, regardless of the state of the Timer Module.

 

[Les Jones]

You will also need a second timer to prevent the the button from applying power to the high voltage generator if it is pressed again just after the 2 seconds have timed out. You will need to work out how long this delay needs to be from the duty cucle rating of the high voltage power supply. (I am using the term high voltage power supply in place of you use of the term "coil" as DC applied to a coil will only generate one pulse when the current through the coil is removed. If your "coil" behaves in the way you describe then it must also contain some electronics.)

Les.

 

[spec]

The spark plug thing was just a example.
I have a high volt coil that can only run a few seconds.
Image from http://g01.a.alicdn.com/kf/HTB1laOx...ator-super-arc-pulse-ignition-coil-module.jpg.

If I supply the coil with switched 12v it will output the spark. If the switch it held for longer then a few seconds the coil will burn out.

That's where I need something to control the switched output. And I don't know what to use.

Thanks
Chris

I didn't have that info when doing the diagram and I see now that it will not meet your requirement.

You will also need a second timer to prevent the the button from applying power to the high voltage generator if it is pressed again just after the 2 seconds have timed out. You will need to work out how long this delay needs to be from the duty cucle rating of the high voltage power supply. (I am using the term high voltage power supply in place of you use of the term "coil" as DC applied to a coil will only generate one pulse when the current through the coil is removed. If your "coil" behaves in the way you describe then it must also contain some electronics.)

Les.

Good point Les. These things are always more complicated than seems at first: switch closed and regardless of anything it has no further effect until the pulse has returned to zero and the igniter had had time to cool off.

It would be nice to use the ready built modules as they would save a lot of work. They are dirt cheap on Ebay, so two modules may not be out of the question. Off the top of my head, I suspect that two would do the job, but not sure at the moment.

The exact function of the modules or better still a circuit diagram would be the thing to have. Can any of the other ETO members help?

Chuck

 

[spec]

Timer module relay data sheet for reference:

http://www.anovay.com/Relay/209020000.html

Not identical timer module but same function I would think:

I am pretty sure that the timer modulke works as I first thought- have some info gatherd from the net about setting the timing value and the use of the timer

 

[chemelec]

The Capacitor and 555 Circuit I previously described to you, will do what you want.

 

[spec]

Depends on What the signal needs to be?
Just a single Capacitor will send a Very Short Signal as power is applied to it.

In conjunction with triggering a 555 timer, it can send a signal of few micro-seconds to 10 seconds or more.

Hi Chem,

Yeah, you could do a nice job given a free hand and a couple of 555s but, from a practical point of view, it would probably be easier to use an off-the-shelf timer modules, especially as they are so cheap. Amoung other things, I'm thinking about using two timers. Once we have finished investigating that approach and if it proves to be impossible/untidy we can have a look at a custom job. Do you have an actual schematic?

 

[chemelec]

I could do up a schematic later today.
6 am, Just waking up now.

 

[KeepItSimpleStupid]

I think you want a non-retrigerable delay on make, but you may in fact want something else.
You need to inhibit, the activation again.

e.g.
Push - you get 2 seconds all the time. release, the 2 seconds still happens.
Push also creates another 4 second timer, this timer disconnects the push button, so you get 2 seconds on and 2 seconds off.

 

[chrisk]

Im trying to make a shocking rat trap. When the rat triggers the switch the hi voltage is a applied for 2 seconds. If the rat dies in place the weight of the rat will still have the switch activated and I dont want the voltage to continue to be applied untill the switch is released.

 

[chemelec]

This Circuit will work for what you want.
If you want a Shorter On Time, a 47K instead of the 82K will give about 1.1 Seconds.

Almost Any Mosfet will be OK.
An IRF640 would be good.