Electronics guys: need a... timer relay?

[Cameramonkey]

I found one at one point, but cant find it now. And the guy who recommended it now cant recall it either.

12-24VDC. I need a device that when I apply 12 or 24v (24v preferred) it activates and passes the current through to the solenoid (external target device). Regardless of whether the power is cut, the device cuts power to the solenoid after a programmed interval has passed and waits. When power is cut from the device, it resets. Lather rinse repeat. Max power delivery is under 5 seconds. Realistically, only 1 second.

This is a mechanical doorbell solenoid that will die (melt) if power isnt removed in a reasonable amount of time. The device that activates it has demonstrated that it cant be trusted to cut power as programmed. Twice. (burning out both the device as well as the source) I figured a $20 relay is cheaper than constantly replacing $100 worth of equipment.

Or if you know of a 12/24V WIRED (traditional, old school) SOLID STATE electronic two door doorbell for $20 or less, I can go that route. Unfortunately every single solid state electronic doorbell I can find is wireless. That wont fly.

suggestions?

 

[Mrcole]

Here is something simple for <$10:

https://www.amazon.com/dp/B01JA28DHA?psc=1

There are other options on Amazon, just search for "power off delay relay"

Another option:
https://www.amazon.com/Miniature-cy...-1-spons&keywords=power+off+delay+relay&psc=1

One other thing you could do is build/find an economizer. The economizer will turn on the relay at full voltage, then hold it closed with the minimum voltage/power required (saving power, producing little heat, etc). Self-economized relays can be kind of pricey so the top options are probably better for your needs. Hope this helps.

Here is a quick read on an economizer circuit:
https://diysecurityguy.wordpress.com/2015/06/01/design-ac-power-monitor/

 

[1911ly]

Just google Time Delay relay. WW Grainger. Allied, Newark or even Digikey can hook you up. They have different voltages/current and time delay range of adjustments. Easy peasy. And simple. Most have an adjustment pot on the top. You can also get them in latching style too.

 

[Razer]

Here you go.

https://www.amazon.com/Elk-ELK960-E...&qid=1498359894&sr=8-5&keywords=12v+relay+elk

This will work perfectly and I've used close to 100 of them with no issues. I use them as one shot siren timers, so power is applied and the siren and alarm will go of anywhere from one second to 60 minutes. Once power is killed the timer resets and will be ready for the next use.

 

[RobbyMaQ]

almost like a flip flop circuit. except it flips, then flops once. until set to go again

 

[Cameramonkey]

awesome. Thanks guys.

 

[Indycar:v1.1]

It's called a one shot time delay

 

[actaeon277]

I haven't used this model, so I can NOT testify to it's ruggedness. But, I have used things from this company "Velleman", and they've been good so far.

You'd have to call Jameco to be sure, but I think this is 2 different versions of the same board. One pre-assembled, one that you have to solder.


If you can solder, and I mean really solder, not just heat blobs of solder and drop them on the board, then the one you have to assemble is cheaper.
Although, it is pretty cheap. But I'd practice my skills on some components first. Remember, solid state devices are sensitive to heat, so they require someone that knows what they're doing.


Need to solder
MK188: Velleman : 1 Second to 60 Hour Pulse-Pause Timer Kit : Electronic Kits & Projects
$19


Pre-assembled.
VM188: Velleman : 1 Second to 60 Hour Pulse-Pause Timer : Electronic Kits & Projects
$32


You'd have to set the jumper for single shot.
Then, I'd have to experiment, but you're either going to wire the NO and common, or the NC and common.

Not sure of your level of experience,, so
http://www.jameco.com/Jameco/Products/ProdDS/2187323UserManual.pdf
example 2
the x in the circle would be your load (doorbell)



Not sure if you can order as a "guest" or if you have to set up an account.
I can always buy for you, and ship it to you.




Or not.
This is just something I found that "should work" and be in your price range.
Most of the stuff I work with at work is industrial rated, and cost in the hundreds. I'm thinking that might be a bit out of your range.

 

[Indycar:v1.1]

Look for a One Shot timer! At least that's what AB calls them