HELP BE WITH EASY ELECTRICAL QUESTION
HELP BE WITH EASY ELECTRICAL QUESTION
(OP)
I am a mechanical engineer and want to design an automated Bartender. This is just for fun. I need to know how I can control fluid in a pipe. The pipe will be set up verically and be blocked off by a valve or something. Then I need to do a control of somesort to tell the valve to move at a rate to allow a certain amount of fluid to pass and then close again. I checked on Mcmaster Carr and other and found information on solenoid valve etc. My problem is I dont even know where to start. Is this difficult? I need to keep this off the shelf and as cheap as possible





RE: HELP BE WITH EASY ELECTRICAL QUESTION
The difficulty of this task depends on a few things. First, how accurate and/or stringent your control requirements are. For example, how accurate and how precise (defined differently) must the flow velocity control be, and/or the shut off velocity. Also, if you are comfortable with mathematical manipulation, such as Laplace transforms and S-domain analysis (or using Z-transforms if you use a digital device for the controller), and can derive a behavioral function to describe the function of the solenoid valve mathematically, then this should be able to handle this. If your control requirements are not that stringent, you could do some rough approximations and avoid the math. Try searching on control system theory/feedback control. It's really an art unto itself. If your requirements are really stringent and none of the stuff I mentioned is familiar, you either have a lot of studying to do, or you can find yourself a good EE buddy.
RE: HELP BE WITH EASY ELECTRICAL QUESTION
RE: HELP BE WITH EASY ELECTRICAL QUESTION
If you start getting a large number of bottles it may be cheaper to have multiple pump heads and a single drive motor. One arrangement would be to have the bottles on a carousel with the drive motor on a slide at the pour station. I would guess this would start to get cheaper over 8 bottles.
One bit of experience on the drive coupling is to make one of the "teeth" higher than the other to help it engage.
Barry1961
RE: HELP BE WITH EASY ELECTRICAL QUESTION
<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032
RE: HELP BE WITH EASY ELECTRICAL QUESTION
RE: HELP BE WITH EASY ELECTRICAL QUESTION
For hard liquer mostly. (beer would be more difficult to do)
The bottles were placed upside down into a rotary carrage the bartender would turn the carrage to the selected Gin or Vodka (my favorites)or what ever, push a button and a premeasured amount would flow into the glass. I suspect that a solenoid opened for a preset time period then automatically closed.
I havn't seen one in years, not all bars had them.
They did'nt take to the designer bottles too well and the customers felt they were getting short pours.
The bartender did'nt have the freedom of giving the better customer the extra splash when he wanted. It takes all the creativity out of bartending. Puts money in the owners pocket, shorts the buyer.
Does'nt mean you've got a bad idea, keep going, maybe you'll do it better.
Good Luck
pennpoint
RE: HELP BE WITH EASY ELECTRICAL QUESTION
Have fun. My friends all thought it was cool at first, but after a few rounds nobody cared any more.
"Venditori de oleum-vipera non vigere excordis populi"
RE: HELP BE WITH EASY ELECTRICAL QUESTION
Remember that engineering is about designing reliable, functional devices in a sound and economical way and hitting the design target. Not shooting way above it.
By the way, my son-in-law built me exactly one of these "dispensers" for my birthday. There are four bottles (gin, vodka, whisky, soda) and four wind-shield 12 V pumps feeding four separate tubings that end in a common nozzle (nbucska warned about cross-contamination) so that the liquids do not mix until they land in the glass.
It is built into an attache case and even has a brass plaque saying "Port-A-Bar. The Original" on it. Very neat and a big success. It is push-button operated, my next project is to install a PIC to do the metering (time controlled) and also have a code lock to prevent unautorised use. My wife says that it could prevent myself from using it overly; unable to key in the code = no more drinks.
RE: HELP BE WITH EASY ELECTRICAL QUESTION
RE: HELP BE WITH EASY ELECTRICAL QUESTION