Make on break time delay circuit

[geochurchi]

Hi All, we are looking to build a TD relay make on break, the situation is we have a model train museum where kids interact with the accessories, all push buttons, the accessory requires that circuit remain live for probably 45 seconds +- , no kid is going to hold a button that long, we want a TD relay that would activate with the push button and remain lives for a adjustable period of time ie 45 seconds or whatever it takes for the accessory to complete a cycle, here is the kicker, the relay can’t reset until the cycle is complete, even if someone pushes the button.
Thanks
Geo

 

[danadak]

Use Arduino Nano board and a SSR to handle the power, mBlock creates the code
to burn into Nano board. This should work.

AC SSR-

Or use (for power relay, in place of SSR) -

1 Channel Relay Module Interface Board Shield for Arduino 5V Low Level Trigger One PIC AVR DSP ARM MCU DC AC 220V: Amazon.com: Industrial & Scientific

1 Channel Relay Module Interface Board Shield for Arduino 5V Low Level Trigger One PIC AVR DSP ARM MCU DC AC 220V: Amazon.com: Industrial & Scientific

www.amazon.com

Project file attached.


Regards, Dana.

 

[danadak]

Something like this (ignore Sharp Part Number, just used as example for SSR) -

Regards, Dana.

 

[geochurchi]

Hi, Thanks for the reply but this is over my head, we can operate on either 12 VAC or VDC , can you explain the circuit? and part numbers we could use, I’ll turn it over to someone more familiar with Electronics then me.
Thank

 

[rjenkinsgb]

You could just use a "Timer relay" module such as available on ebay for trivial costs.
Examples:

12V Timer Relay for sale | eBay

Find great deals on eBay for 12V Timer Relay. Shop with confidence.

www.ebay.co.uk

If the module itself does not lock out the trigger button, just use a small auxiliary relay operated by the timer, that breaks the circuit to the start button.

 

[schmitt trigger]

What you described is called a non-retriggerable monostable.

 

[geochurchi]

Hi, that’s what I am trying to do is lock out the button, can you describe or draw the circuit, would that require a second TD relay?
Thanks

 

[eTech]

Hi All, we are looking to build a TD relay make on break, the situation is we have a model train museum where kids interact with the accessories, all push buttons, the accessory requires that circuit remain live for probably 45 seconds +- , no kid is going to hold a button that long, we want a TD relay that would activate with the push button and remain lives for a adjustable period of time ie 45 seconds or whatever it takes for the accessory to complete a cycle, here is the kicker, the relay can’t reset until the cycle is complete, even if someone pushes the button.
Thanks
Geo

Hi

Here is a non-retriggerable 0-75 second adjustable Timer.
If the button is pressed, time will run. If the button is pressed again before time has expired, the button will be ignored.
It can be powered with a 12v Wall wart.
See below

 

[danadak]

Hi, Thanks for the reply but this is over my head, we can operate on either 12 VAC or VDC , can you explain the circuit? and part numbers we could use, I’ll turn it over to someone more familiar with Electronics then me.
Thank

The board is Arduino Nano
The SSR or relay you pick according to your load requirements, and must have a 5V control input to
turn relay on/off.
The software, if you want to modify it, is mBlock. The project is attached in prior post.
You need a pot, say 5K or 1`0K, for creating the variable delay time requirement.
You need a pullup resistor for button, use 4.7K 1/2W
If you want to limit range of delay capability from 0 - 1023 secs to say 0 - 255 secs, then
connect a 15K R in series with pot to Vdd (for pot 5K) or a 30K R in case you chosse 10K
pot. 1/2 W
If you have 12V you need 5V to run Arduino Nano board. A 5V 3 terminal regulator needed.

Note delay times are quite accurate and do not change appreciably with temperature.

Thats it.

If you do not want to use Nano board you can use ATTINY85 in its place. Programming it
a tad more involved than the Nano board which programs directly from USB and mBlock.
You would still use mBlock but would need an Arduino board to do the programming of
the part.

Regards, Dana.

 

[Pommie]

This may not be as simple as you expect. If a model has to be powered for a certain amount of time then any error will accumulate over time and the exhibit will be out of sync. Is there some way to place a microswitch in a "rest" position so it always stops in the same place? You would then just need a latching relay that is latched by the push button and unlatched by the microswitch.

Mike.

 

[geochurchi]

It certainly isn’t as easy as expected, one of the other guys was thinking of trying to mount a micro switch.
The thought was that the TD relay would be set long enough for the accessory to run a complete cycle, at which time it would return and stop as designed.

 

[danadak]

If exhibit has audio video might be able to use photocell to detect end of exhibit,
eg. video screen turning off or motion stopped or sound stopped. Easy for micro
and appropriate sensor to do this. Could even detect no people at exhibit, eg. walk
offs....and power exhibit off, a green measure.


Regards, Dana.

 

[geochurchi]

No audio/ video .
Thanks

 

[Pommie]

A light break circuit could also be used to power off the exhibit. Are most exhibits running trains? A section of track could also be used as a trigger to power off the exhibit but it starts getting complicated.

Mike.

 

[crutschow]

all push buttons, the accessory requires that circuit remain live for probably 45 seconds +-

What's the time tolerance?
What if it goes over the allotted time?

It the timing is not critical, I would use etech's 555 circuit.
[Actually R2, R3, and C3 can be eliminated, as long as the button push is shorter than the timer period (which it should be) to simplify the circuit.]

 

[AnalogKid]

15 posts, very little design information.

What is the system voltage to power the button and timer circuit/device?
What are the voltage and current characteristics of the electrical signal being controlled?
What is the minimum time allowed for the timer circuit/device to reset itself so the next button press gets the full 45 seconds?
What is your skill set for assembling and debugging a small circuit on perf-board? Is using pre-assembled module(s) preferred? Strongly preferred? Despised?

ak

 

[Dr_Doggy]

I agree with Pommie, a stop button would be more accurate, and then it could be controlled with a simple flip-flop circuit , and maybe triggered with a magnetic sensor and a magnet on the train

 

[eTech]

It certainly isn’t as easy as expected, one of the other guys was thinking of trying to mount a micro switch.
The thought was that the TD relay would be set long enough for the accessory to run a complete cycle, at which time it would return and stop as designed.

What stops the accessory now?
Is there a track occupancy sensor available?
Based on what I can deduce by the previous posts (which isn't much) probably just need a latch.
Latch on by spectator button press, latch off by accessory return..

 

[geochurchi]

This is a description from 1 member, we need to keep it simple.

 

[eTech]

This is a description from 1 member, we need to keep it simple.

View attachment 133258View attachment 133262

Ok....I'm confused. Who's Bob?

So are you talking about a (hot air) Balloon ride or a model train reversing loop?