Friday’s Tips & Tricks: The Slide Dimmer and Dimmer Bits



Today, we will explore two awesome Bits at once: the dimmer and the slide dimmer. They look quite different but their functionality is similar. As their name implies, these bits control the strength of the output (i.e. how bright you want a light to be). To see what they do, let’s begin by building a very simple circuit: power + dimmer + bargraph.


See what happens when you turn the knob. Replace the dimmer with a slide dimmer and see how the two compare.


As you see above, the dimmer and the slide dimmer are very useful Bits when you want to control the strength of the electricity in the circuit. With these Bits, you can control how quickly a vibration motor vibrates, how loud a buzzer sounds, how bright an LED shines, and much more. With both dimmers, the circuit is totally off when the knob is located or rotated all the way to the left. When you slide or turn the knob all the way to the right, the circuit is totally on –  an LED will shine its brightest and a buzzer will sound its loudest.


While playing around with dimmers and slide dimmers, we wondered how far we should turn/ or slide the knob to generate a specific amount of power, so we performed a simple experiment. We put a power, a dimmer and a bargraph in series and turned the knob on the dimmer very slowly, from the left end position to the right. We stopped and checked its position every time a new led on the bargraph lit up.







We did the same experiment with the slide dimmer.







As shown above, they are not exact, but they are roughly linear. This means that if you set the knob half way, you generally allow half of the power to go through the circuit.


1. Bigger Knob

The original knobs on both the dimmer and the slide dimmer are so tiny that it is sometimes hard to pinch and control them. We thought it a good idea to attach something to the knob to make it bigger.

Cardboard is a good material to use to make the dimmer knob into a larger dial. It is easy to find, easy to handle, cheap and strong. One thing you should remember is that the knob on the dimmer is actually a D-shape, so make a hole on the cardboard accordingly. If it were all round, the dial would spin alone, not turning its axle (the original knob)


Be creative and try other materials like popsicle sticks or wire.


2. Understanding Distance 

The slide dimmer can be used to sense the distance between objects. For example, you can have a boy run faster when a zombie gets closer to him. The zombie is attached to the slide knob and the boy’s feet are on a DC motor. When you slide the knob to a higher power position, the DC motor turns faster and consequently, the boy runs faster.




3. Embedding a Dimmer Bit 

The design aesthetic of your invention can be very important to your overall project. Hiding your circuit within a fancy box is a nice way to design your project. However, you usually need the knobs on your dimmer to be seen and accessible from the exterior in order to activate it easily. This means you need to have a hole in your box.
According to our dear Vernier Calipers, the diameter of the dimmer knob is about ¼ of an inch. It is exactly the same diameter as the purple littleBits screwdriver you find in any littleBits kit. You can use it to mark the location and size of the knob.

Cutting out the hole with an x-acto knife is one good way, but you can also make a hole using a pencil. Pencils are a little bigger than the knob and make a great boring tool.






We made a mood light with a dimmer. The circuit sits in a small box and has a dimmer knob that extrudes from the surface through a small hole made with a pencil. Now your mood light looks good and is fully controllable.




Have a look how we made a project fancier by embedding the dimmer in a cardboard box.

Bristle Bot


The littleSpace Command Capsule project is a great example of how much fun you can have with the slide dimmer. Launching a rocket is a very delicate and complex process, so we need to be careful controlling its power. This is where slide dimmer comes in handy.

littleSpace Command Capsule

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