# Vibrating Christmas Tree Instructable from our London Engineering Team

### Introduction

Christmas time in Northern European countries is a time of rest, feasting for the cold months ahead, and spending time with family. For our readers with children, you’ll know all too well that keeping them busy and engaged is important. Also being engineers, Christmas is a great break to hack together some fun projects.

This is a simple project that some of us have done with our own Children and can be assembled in the few hours after Christmas lunch when all the adults in the family mysteriously fall asleep!

#### Step 1: Materials

Here you can find a list of the materials needed to create your own vibrating Christmas tree.

The kind of motor needed to shake a tree!

• Christmas tree. Pretty obvious, we know. Ours was a metre high and weighed about 1kg. (Check that no elves are living in it or you may give them a headache).
• PMD vibration motor.  A larger motor is a great choice to make your tree shake. For example, a 324-401 (12v) would be a great choice. We happened to have a spare 334-800 (24v) sample, so used that.
• Power supply. Unfortunately, motors still require electricity to work. We are working on that, but we cannot promise we can deliver our 2018 range of motors defiant the laws of physics. Make sure that the power supply matches the voltage range of the motor on the motor datasheet. An in-expensive power-brick from an old laptop or old phone charger can often work well.
• A pair of wires. You will need them to connect everything.
• Cable-tie. Use this to secure the motor to the tree trunk!
• Rope. You better tie the tree, otherwise, it will probably be jumping around your desk
• Tinsel and snowflakes. It makes everything looks more festive.

#### Step 2: Design your circuit

Here is just an example. The voltage source in our case was a bench power supply, but you could use a battery or an old appliance charging plug (but check the voltages required first!)

An example circuit for driving the vibration motor

#### Step 3:  Mount the motor into the tree

Can you spot the vibration motor?

Make sure the motor is securely attached to the trunk of your tree. A cable-tie is great for this. The higher you mount it, the bigger the displacement at the top will be!

#### Step 4: Secure the tree on your bench

Two or three points will be enough to keep your tree vibrating in the same position. If the vibration intensity is too high, use a lower voltage power supply. E.g. use a 5v USB charger for a 12v motor. Just double-check the current draw from the motor is less than the 500mA or 1000mA typical.

### And Finally…

The sales engineering team here in London would like to say a big thank you to all of our customers for a very successful 2017. Your business has enabled us to once again re-invest our year’s profits into more engineering infrastructure, capability and significantly, a brand new value-add manufacturing lab as part of our Hong Kong office. Once the refit is complete, we’ll be in touch with you all, to present our new services and capabilities.

Festive greetings from the PMD London Engineering Team!

Meanwhile, we wish you a Merry Christmas and successful 2018 together!