Film-Tech Forum ARCHIVE: How does my Pepsi machine work?

This is topic How does my Pepsi machine work? in forum Film-Yak at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=8;t=006183

Posted by Mike Blakesley (Member # 26) on 06-07-2010, 10:47 PM:

We have this Pepsi machine where the cup sits at a slight angle on the tray, and flow stops automaticallly when the soda runs off the top edge of the cup and contacts the metal bar.

How the hell does this work? Even if the bar is still wet from a previous pour, it works right away with the next pour. Is it the temperature of the liquid?

We've had this machine for about 6 years and none of the Pepsi guys have ever been able to tell me how it works, so I'm turning to the most intelligent group of folks on the web...how does it work???

Posted by Randy Stankey (Member # 64) on 06-07-2010, 11:24 PM:

Conductivity between an electrode at the top of the spout and the chute or some kind of inductive sensor are my guesses.

Posted by Jeremy Weigel (Member # 4208) on 06-08-2010, 03:00 AM:

We have the same machines. If you grab the metal bar in one hand and depress it without having the stream touch you and then touch the stream with your other index finger you can make it stop like magic. Do this all the time to freak employees out.

Maybe its similar to how a touch lamp works...

Posted by Monte L Fullmer (Member # 2797) on 06-08-2010, 09:42 AM:

Graphite or carbon in the plastic tang lever that senses the moisture as a ground to close a circuit to the head unit via the use of a microchip.

I was shown this about a dozen years ago from the Pepsi installers.

Posted by Richard Hamilton (Member # 321) on 06-08-2010, 10:13 AM:

Magic ??

Posted by Dave Macaulay (Member # 813) on 06-24-2010, 09:51 PM:

It doesn't matter how wet the bar is, the inside of the new cup is dry. A low voltage is imposed between the drink nozzle and the bar. When the drink gets to the top of the cup and touches the bar, there's a small current flowing through the Pepsi - from the nozzle (through the flow into the cup), through the drink in the cup, to the bar. That current is sensed to close the solenoid valve controlling the drink flow.
Metal cups will not fill at all, the valve shuts off as soon as the stream of Pepsi touches the cup bottom.

Posted by Mike Blakesley (Member # 26) on 06-25-2010, 10:46 AM:

Thanks, Dave -- that makes the most sense so far. Although I think I'll continue to use Richard's explanation for employees and the other curious folks!

Posted by Jeremy Weigel (Member # 4208) on 06-25-2010, 11:40 AM:

quote: Dave Macaulay
Metal cups will not fill at all, the valve shuts off as soon as the stream of Pepsi touches the cup bottom.

Actually had an employee bring a metal lined coffee cup to use on his break a couple of days ago. I stood there watching with amusement as he got frustrated that his cup wouldn't fill except in small bursts. He finally came over and told that something was wrong with ALL the towers. With a smirk on my face I went over grabbed a paper cup and filled it up. Told him it seems to work fine to me. He then put his cup back on only to have it not fill. He stood there bewildered. I finally explained to him what was happening and used the paper cup to fill his metal cup. I got some amusement and he got a lessen on how the drink towers work. [Big Grin]

Posted by Randy Stankey (Member # 64) on 06-25-2010, 11:54 AM:

Next time, get a piece of paper or something (a piece of a drinking straw?) and place it between the cup and the metal conductor so that the cup will fill. Don't let him see it. Palm it or something.

Then you will have performed the same trick using HIS cup!

You could potentially screw with the kid's mind for months! [evil]

Posted by Jeremy Weigel (Member # 4208) on 06-25-2010, 12:27 PM:

Oh trust me, that thought did cross my mind.

Posted by Randy Stankey (Member # 64) on 06-25-2010, 01:42 PM:

That joke would rank right up there with sending the newbie out to the hardware store to buy a can of Technicolor. [evil]

Posted by Phil Hill (Member # 371) on 06-25-2010, 01:50 PM:

...or sending out the FNG electronic repair kid out to get some fallopian tubes.

Posted by Mike Blakesley (Member # 26) on 06-25-2010, 06:13 PM:

quote: Jeremy Weigel
If you grab the metal bar in one hand and depress it without having the stream touch you and then touch the stream with your other index finger you can make it stop like magic.

Well -- I tried this on our machine and it did not work -- the stream just kept on flowin'. So I'm beginning to think it really IS magic.