# Inside a Drink Vending Machine

By Numa

Topic: Machines

[Open the interactive Jig](https://ask.jig.com/j/tMrl1VIpucvN)

## Guide

### 1. Inside a cold drink machine

This glass\-front machine stands 1\.8 metres tall and holds hundreds of cold bottles on five trays\. We have lifted away its left wall and the panel under the glass so you can follow one bottle from its tray to your hand\.

Drag empty space to turn the machine and look inside\.

### 2. Keeping everything cold

Under the trays sits a refrigerator that slides out in one piece\. The compressor squeezes the refrigerant and pushes it hot through the condenser, where a fan blows the heat away\. At the back it boils in the evaporator and soaks up heat, and a second fan blows that cold air up through the floor grille to the drinks\.

The factory setting is 37 °F, about 3 °C\.

### 3. Paying in

Behind the narrow service door, the coin mechanism checks each coin's size and metal, then drops it into a tube it can pay change from later\. The note validator scans a banknote and stacks it in a locked box\. Both tell the controller board how much credit you have over one shared data cable\.

That cable standard is called MDB, short for Multi\-Drop Bus\.

### 4. Make your choice

Each tray has a letter and each column a number\. Tap B and then 4 on the keypad, or use the button\. The controller checks your credit, the price and that column B4 still has a bottle before anything moves\.

### 5. The picker cup sets off

This machine does not drop its drinks\. It sends a small cup to fetch them instead\. One belt slides the upright column sideways along its top and bottom rails, while a second belt lifts the cup up the column until it stops in front of B4\.

### 6. The gate lets one go

A plunger on the cup pushes the gate at the front of B4\. The front flap drops out of the way while a rear flap rises to hold back the rest of the line, and a kicker nudges the first bottle into the cup\. Then a spring\-loaded pusher slides the remaining bottles forward\.

### 7. Delivered, with change

The cup carries the bottle down to the delivery port, where a motor slides a door open and the bottle slides through\. A light beam in the port sees it arrive, and only then does the coin mechanism pay your change from its tubes\. The cup stays by the port, ready for the next customer\.