Electronics 2000

Hello, I'm a newbie to the forum, so many thanks for letting me join! I'm hoping that some kind people on here can help me with a little project I'd like to do (if it's possible!) I did electronics in college/uni an number of years ago, but it's been a long time since I've actually designed/made anything which is why I'm looking for some help. I'm looking to make project that controls a mini peristaltic pump. The pump i.e. motor is 12vDC and rated at 170mA and can pump approx. 83ml per minute. I'd like to make some sort of control circuitry that can run the pump for X number of minutes and then turn it off, where X could either be fixed or variable time. Ideally I would like it to run off rechargeable battery' the type used for intruder alarm backup (12v) but if this is not possible it wouldn't be a problem. I've been looking at 555 timers as an option but would appreciate any help/advice as to whether they would be suitable or not. Any help would be much appreciated.


Kind regards

Craig

Have a search for a 12v cyclic timer

Hi Craig,
There are several options available to you, 3 spring to mind off of the top of my head.

1. A simple R/C circuit, this could be made variable by using a variable resistor. In theory it's the simplest however it could take some tweaking depending on the chosen components, interactions with other components etc. http://www.electronics-tutorials.ws/wav ... table.html

2. Use a 555 timer in one shot mode, this link should help http://clarkson-uk.com/555-timer/operation/frames2.html

3. Use a small micro-controller. It can seem like overkill to use a micro-controller for such a simple function, however by the time you add up the component value of other solutions a micro-controller often comes out on top price wise. Especially if you may want to add extra features in the future. Of course this does assume that you have already mastered the learning curve for programming a micro.

Nick