Timer relay question! Help needed please.

[yazen]

Hi All,

Hope you guys are doing well.

I have a question on how to energize a timer relay ( this is the timer http://ca.digikey.com/1/1/53823-relay-timer-dpdt-analog-120-240v-h3cr-a-ac100-240-dc100-125.html)

I know how to wire a timer relay, but this is the senario:

I need to have a push botton (normally closed) pressed to reset a circuit in my car, the way i wanna set it up is, to hook up the timer relay with the door switch, so when i open the door, the door switch would power up the timer, and the timer will reset the switch in few minutes. The only issue which i am having at the moment is that, i have connected the timer (-) to the door switch and (+) directly from the battery, so when i open the door it would energize the timer and when i shut the door the timer would loose power! and i am unable to achieve what iam looking for. Need an advice on how to connect the timer to the door switch and would get powered as soon as i open the door and would stay powered when i close the door so it would reset a switch after few minutes?

Thanks,
Yazen

 

[TBennettcc]

Judging by the datasheet here, it looks like the reset input should be a NO, and then momentarily close to reset.

Page 7, under 'I/O Functions':

Reset: Interrupts time-measurement and resets time-measurement value. No time-measurement is made and control output is OFF while the reset input is ON.

You might want to take a look at pages 16-18 for some common usage examples.

Post back with any questions.

 

[yazen]

TBennettcc, thank you for the reply.

The link to the time relay is wrong, sorry. Pictures of the relay which i have are attached here. So, if i connect 2&7 to energize the relay, and connect 8 to the door switch, it would be shorted with 6 but as soon as i shut the door the door switch will turn off and the relay will be useless here! what is the correct way of connecting it so that when i shut the door the relay pins 8 and 6 remain shorted?

Thanks,
Yazen

 

[TBennettcc]

I need to know EXACTLY what you want. Details, details, details. It's pretty darn vague in your first post. From what I can understand, you want the circuit to turn on when you open the door. Does it start counting when the door is open? Or do you want the light to stay on the whole time, and the circuit only starts counting after the door is closed?

You say you need to have a NC push-to-reset button. Are you referring to the switch in the door to control the light? Or some other switch? What is this button resetting? When is it doing the resetting? When it is open, or when it is closed? When is the light on (switch open or switch closed)? What kind of time are you looking at for this light to be on? When does the time start? Do you want only one door on the timer, or do you want all doors on the timer?

You say you want to power up the timer from the door switch. Well, if the light needs to stay on after the door is closed, then this obviously won't work. You'll have to decide on another way to power the timer. Maybe we can figure something out after we get more details...

I'm guessing you're probably not going to be able to do what you want with this timer. Do you have any other documentation for this thing other than the schematic on the back? A manual you could scan and post? (A schematic of your car's lighting system would be awesome, too. Have a Hayne's manual, by any chance?)

'A' and 'B' appear to be a manual override switch. When 'A' is selected, the timer functions as normal for pins 3 and 4. When 'B' is selected, you can use a switch/button on the timer to manually control the connection (either pin 1 to pin 3, OR pin 1 to pin 4). The switch has no bearing on the connection of pins 5 and 6 to pin 8.

There has to be some kind of trigger functionality, unless this timer just starts when power is applied, and counts from there.

It appears that contacts 1, 3, and 4 form a single-pole, double-throw switch. You might connect your light to either pins 3 or 4, depending on which pin is connected to pin 1 when the timer is on.

Remember, the more information you provide, the better we can help you.

 

[yazen]

Hello TBennettcc,

Thanks for your reply.

Okay i will answer all the question but lemme give a background on what iam exactly trying to do here.

I made this device, (http://triumphspitfire.rickbaines.com/the-worlds-best-diy-immobiliser/) the way it works, you swipe the magnet on top of the reed switch, the circuit will complete and it would be on, to shut it off, a reset switch (NO) should be pressed once to deactivate the circuit. I am trying to have the reset switch automatic, by connecting it with the door switch, so when i open the driver's door it would energize the time relay and the relay is set to trigger the reset switch after 3 minutes and goes off.

The resetting is done after three minutes from opening the driver's door. The time count should start as soon as the door open.

I want the driver's door to be connected/able to reset the switch only and none of the other doors.

The time relay did not come with any documentations

Thanks again, TBennettcc

Yazen

 

[TBennettcc]

Okay. From the article, the reset switch is NC, not NO. When the reed switch is energized, it pulls power from the 12VDC in, through the relay coil, over the reed switch, and out through ground. There is a wire connected from between the coil and the reed switch, to one NO contact of the relay. After the reed switch completes the circuit, even momentarily, the relay coil has an alternate path to ground through the NC switch. As soon as this NC switch is opened, it breaks the circuit of the relay coil, de-energizing it. The relay resets, and the LED lights.

Before I go any further, can you verify for me that the timer starts as soon as power is applied to the timer unit, and counts from there? Say, set the timer for 10 seconds (Slide the 'X1 / X10' switch to the 'X10' side, Slide the 'S / M' switch to the 'S' side, and rotate the needle to 1.0) and let me know what happens. If this is the case, we'll need to have the power disconnected from the timer until such time the time is to start.

 

[yazen]

Hello TBennettcc:

Thanks for your replay.


Yes, the timer starts as soon as power applied to it and counts from there three minutes.

What happens at the moment is: As soon as i open the driver's door, the door switch would power the time relay but as soon as i shut the door, the power would disconnect and thats it, what i am trying to find out how to keep the time relay energized even after i shut the door and it would reset the other circuit for me after three minutes and then the time relay should shut off.

The time relay i had previously didnt work so i bought another one, picture attached.

Thanks again TBennettcc for all your help and support.

Yazen

 

[TBennettcc]

I'm not sure if you are insisting on using those timers, or you just think they will work. Unfortunately, from my perspective, they will not work. You need a constantly powered circuit with a trigger input, not a circuit that gets entirely de-energized. That appears to be what that timer does. To reset that timer, you must de-energize it, then re-energize it again. When power is cut to the timer, the timer shuts off and resets, as well as anything that the timer was powering.

I am trying to design a circuit for you using a 555 timer. It's going to take me a little bit, as I am not entirely familiar with 555 timers, or designing circuits, or how some of the components come together. However, I have had a bit of experience in computer programming. That's really all circuit design is, programming with electricity. (That's part of the reason I joined this forum; to gain electronics experience, and try to put that knowledge and experience to use by helping other people solve their problems. I'm reading an online course here, that so far has been amazing. I highly recommend it.)

If anyone else sees a solution to this before I do, feel free to jump in.

 

[TBennettcc]

Well, so far, I have been unable to come up with a solution to this problem. However, I think I have been able to boil the problem down, if anybody else would like to give it a crack. (I've been trying to use 3 555 timers, but I'm sure somebody can up with a better solution. I'm sure a microcontroller could do the job just fine, but I don't know enough about them to recommend a solution.)

The initial states are as follows:
Door trigger is at 0VDC with door closed, 12VDC with door open.
Normally-closed momentary switch (replace with a transistor?)
We are able to have a constant +12VDC power in from the car battery.

Functional requirements:

There will be a +12VDC pulse when the door opens (duration can vary). As soon as the door opens, we need the timer to start. Timer should be approximately 3 minutes, regardless if the door is opened or closed any more. Timer should be able to be cancelled by some external means. Once the timer expires, we need a (transistor?) to break a circuit for approximately 10 seconds (duration is not important; just need enough time for a relay to de-energize). This transistor needs to be on ALL the time, EXCEPT for when it is being temporarily de-energized by the circuit.

I think that's all the details.

Can this even be done with analog circuitry?

Thanks for your time.

 

[yazen]

Hello TBennettcc,

I would like to thank you for trying to help me and for re phrasing the issue.

One point i would like to add here! the car ignition doesnt need to be turn off or on for the circuit to work! it doesnt matter, so if the ignition is turn off and i open the door, the timer should start counting! and even if the ignition is on and i open the door the timer should start counting.

Thanks once again,
Yazen

 

[TBennettcc]

If the ignition is on, and you open the door, and the timer is not reset, it will kill the car at the end of the timed sequence. The car will not be able to be started again until the reed switch is reset. Something to think about.

 

[yazen]

Yes, this is exactly what iam trying to achieve. If someone on a gun point stops me and wants to run a way with the car, i want the car to turn off after three minutes. But if i open the door while the car is on for any reason, there is enough time (three minutes) for me to reset the reed switch.

Thanks again,
Yazen

 

[TBennettcc]

I see where you're going with that. However, you would need to reset the timer itself, as by the time you need the reed switch, the car would already be off. The reed switch is only a momentary component to enable the relay coil to energize, and is kept energized only by the NC switch.

My electronics experience is elementary at best. Wish I could've figured it out. I know I've seen a few posts on here so far that when I've looked at the solutions, my reactions have been nothing but "...what a flippin' genius!"

Resqueline or Steve, if you've got some time and wouldn't mind taking a look at the functional requirements I posted about 4 posts back, I'd sure appreciate it. Unfortunately, I think I'm in over my head here.

 

[yazen]

Hello TBennettcc:


I 've been searching online for the type of circuit that i need to use here and i THINK i found what i am looking for but since iam just a beginner i need an expert to give me opinion/ advice and suggestion if this is the correct type of circuit which i need to use in my project before i go ahead and purchase the items.

Its found on this link: http://www.bowdenshobbycircuits.info/page9.htm

Tittle of circuit is: Relay Toggle Circuit Using a 555 Timer

Please advice

Thanks and kind regards,
Yazen

 

[yazen]

Gents,

Just found more circuits and wondering if any of them would do the job, here are the links:

http://www.kpsec.freeuk.com/projects/timer.htm
http://www.555-timer-circuits.com/driving-a-relay.html
http://www.technologystudent.com/elec1/5554.htm


Your comments are highly appreciate it.

Thanks,
Yazen

 

[TBennettcc]

Take a look here:

https://www.electronicspoint.com/need-some-help-creating-timer-circuit-t237058.html

Let me know what you think. How comfortable would you be with trying a microcontroller?

 

[yazen]

Thank you, TBennettcc:

I gave up the idea of making the device

Thank you once again,
Yazen

 

[(*steve*)]

Here's another idea for you yazen.

You set up a 555 timer which has an on period of a couple of seconds and an off time of (say) 30 seconds. You use this to short the points (if you have them!) for a couple of seconds at a time.

If someone takes your car then it will run fine for a while then stall. This will repeat over and over again. Anyone trying to get away with your car will probably give up and assume it's very unreliable.