I’d like a random start delay. But also want a simple solution. If a particular simple solution is unpredictable, whoa, I’ve hit the jackpot

A simple circuit or module that gives an unpredictable result is preferred. You guys sometimes are so focused on the perfect answer, you miss that sometimes the imperfect answer is the perfect answer.

You've changed the requirements mid-task. Should have seen that one coming.

 

I’ve mentioned the preference (not requirement) of an unpredictable start delay in posts #8, 13, 15 & 18... I can’t be responsible if you can’t read. I’ve reviewed my posts and can’t see how you came to your conclusion in post #20.

Sorry if my post has been misinterpreted. Thanks to most of you. @sghioto, you’ve been ignored. Personally, I feel that you’ve earned it.
Note: Not sure who I meant. It wasn’t @sghioto

 

You've changed the requirements mid-task. Should have seen that one coming.

Sorry, I see it as adding more specific requirements based on the feedback I’ve received. I initially did not specify the requirement of the delay specificity as the only requirement was a delay between the trigger and the motor action. The repeatability and the delay was irrelevant and thus not specified.

If the action is repeatable, then OK. But not necessary. If the action is random, then OK. But not required and thus not specified

AFAIK, I haven’t changed the requirenents. Others may have perceived requirements that were unstated, but I can’t feel responsible for that.

 

Creating a design to meet a set of requirements was the way it had been done at all of the companies I worked at. And it was important to have those requirements defined.
For an entertainment box such as this project, there are some novel methods of providing a start with a random delay, and a simple method of providing a start after a seemingly random number of button pushes, if that could be accepted. But that would require a small amount of electronics to implement, and it is not clear to me if that is acceptable.

 

I like your use of acceptable. The requirement was “providing a start with a delay”. I didn’t feel like I added “random” to the requirement. What I meant to say is that a random delay was acceptable. I just couldn’t think of the word “acceptable” and misused the word preferable. I became concerned when it was suggested that/when I apparently changed the requirements.

 

A system that started the motor after some quantity of button pushes would be fairly simple, using only one logic IC and a transistor and probably 3 cheap diodes. And a noisy button would make it really random. The total unknown is if the TS is able to wire a 16 pin DIP IC.

 

A system that started the motor after some quantity of button pushes would be fairly simple, using only one logic IC and a transistor and probably 3 cheap diodes. And a noisy button would make it really random. The total unknown is if the TS is able to wire a 16 pin DIP IC.

In the most abstract interpretation of “providing a start with a delay”, your proposed solution might apply. But isn’t appropriate for a Useless Box. Again, you’ve replied to a thread without reading it all.

The TS (me) has several threads on AAC including Completed Projects, which use several 16 pin DIPs among others (8 pin DIPs, Atmega328, ATTiny, OpAmps). Including one simple project for a pseudo-random number generator for gaming using a noisy button. And another implementing the hardware for a run-time system to control animatronics based on a personally developed proprietary language and compiler.

I’ve gotten my answer and thanks to everyone.

 

Again, you’ve replied to a thread without reading it all.

That's just amazing, that you think he would do that!

 

What are you building? If we know we can help and direct.

When Max Headroom said the delay would be unpredictable - I think - and this isn't to say this is what he was saying, but I think he meant that the delay can vary by a few milliseconds to several milliseconds. Maybe even tens of milliseconds. But it's sounding like you want to flip the switch and have the delay occur with a minimum of 1 second and a maximum of 8 seconds. And I'm just pulling numbers out of the air.

So, what are you building?

 

What are you building? If we know we can help and direct.

When Max Headroom said the delay would be unpredictable - I think - and this isn't to say this is what he was saying, but I think he meant that the delay can vary by a few milliseconds to several milliseconds. Maybe even tens of milliseconds. But it's sounding like you want to flip the switch and have the delay occur with a minimum of 1 second and a maximum of 8 seconds. And I'm just pulling numbers out of the air.

So, what are you building?

As stated in post #3 #5, I am retrofitting a poorly designed “Useless Box”. A Useless Box is a toy that is effectively “useless”. It has a toggle switch that you turn on. The box lid opens, a “hand” comes out and turns the switch off.

On the one I purchased, the motor activates too fast and the effect is lost. I want a delay (~300ms?) after the toggle is flipped before the motor activates.

My original idea was to add a cap... or use an adjustable relay module. Given the responses, that is what I’ll try.

I think a lot of confusion resulted from people not realizing what an Useless Box was. Maybe not.

 

Thank you. However, in post #3 it wasn't you who said it was a useless box project it was nsaspook who said that. I got the impression that was what you were after but to me it was never made clear. Maybe it's just me who's slow around here; so that's why I asked.

The "Useless Box" projects I've seen on YouTube "Probably" use a micro to control the response. True randomness is something the µC can do easily. Where Max was suggesting an unpredictability it's my presumption that he means the timing won't be consistent. But probably not so inconsistent as to present the 1 second to 7 second variability I randomly picked. IF that's your hope - 1 to 7 sec. delay - then that's not going to be easily achieved by using relays and caps. That's where a µC comes in. And I don't know programming, so - I can't help.

 

Thank you. However, in post #3 it wasn't you who said it was a useless box project it was nsaspook who said that. I got the impression that was what you were after but to me it was never made clear. Maybe it's just me who's slow around here; so that's why I asked.

The "Useless Box" projects I've seen on YouTube "Probably" use a micro to control the response. True randomness is something the µC can do easily. Where Max was suggesting an unpredictability it's my presumption that he means the timing won't be consistent. But probably not so inconsistent as to present the 1 second to 7 second variability I randomly picked. IF that's your hope - 1 to 7 sec. delay - then that's not going to be easily achieved by using relays and caps. That's where a µC comes in. And I don't know programming, so - I can't help.

Oops, post #5

And it’s a poorly designed toy. No micro.

 

If you're looking to delay a relay for a moment there's an easy way to do that. Use a relay and the C & NC contact points. When you switch the switch on, the capacitor will pull the relay in instantaneously for a few moments. Relay coil resistance and capacitance size matter. The relay will pull in and open the NC contact delaying the motor until the cap charges and the relay falls out, closing the NC contacts.

I have a 12V relay (RE030012) with a coil resistance of approximately 270Ω. With this cap I get about 200mS delay. That is to say the relay turns on for about 200mS then falls out. This is actual bench testing, not theory. If the relay is wired in parallel with the motor, when the power is switched on the motor AND relay will activate. However, as soon as the relay activates the motor will drop out. Once the cap charges sufficiently the relay will drop out and provide pathway to common ground. You might experiment with different capacitor sizes to get different time periods. But you will always get the same result. No 1 to 7 second variability.

 

Oops, post #5

OK, yeah, I recall reading that. It just didn't register. I think you said it was a poorly designed useless box that you wanted to retrofit. If I would have paid closer attention I would have gotten that point.

 

OK, yeah, I recall reading that. It just didn't register. I think you said it was a poorly designed useless box that you wanted to retrofit. If I would have paid closer attention I would have gotten that point.

Apparently, it didn’t register with a lot of folk.

And I took a lot of grief because of that.

 

"ROUND" is a "shape"!

LOVE it.