Motor Running On Timer Then Shutting Off

[FuzzyEllis]

Hi guys,

I hate coming onto forums and asking for help straight away, but I am a total noob so I have to start here I think

I've been looking into making a timer circuit which will run a motor for a set period of time (2-20mins say, on a simple variable dial set-up - doesn't need to be precise times) and then shut off. I'm planning a simple model boat which I can launch and leave to keep going for a predetermined length of time. I want to stay away from radio gear, hence the timer option.

Having searched on here all the threads I could find seemed to be much less basic, i.e. run a motor then shut off then run again, etc.

I know there are a huge number of variables, such as motor type, size, etc. but I don't know any specifics at the moment as I'm very much in the planning stage, so thought I'd see if someone could provide some information which will give me the background. Can anyone tell me if there's a standard circuit set-up for this and how the various motor variables affect the design of the timer?

Thanks in advance for any help

 

[4pyros]

Soulds like a one shot timer.
It can be made with a 555 timer chip set up as a variable monostable timer.
This should be all you need.
Start here;
https://en.wikipedia.org/wiki/555_timer_IC#Monostable

 

[FuzzyEllis]

Cool, thanks 4pyros, I'll check it out

 

[alec_t]

The 555 alone won't be good for a 20-min period. You might use one to clock a counter IC.