Collaborate Disseminate
Potentiometers, or variable resistors, are a standard component that we take for granted. If it says “10k log” on a volume pot, than we fit and forget. But if like [Ben Holmes] you are modelling electronic music circuitry, some greater knowledge is required. To that end he’s created a rig …read more
Continue reading Characterising A Potentiometer With A Stepper Motor
Whether with projects featured here or out in the real world, we have a tendency to focus most upon the end product. The car, solar panel, or even robot. But there’s a lot more going on behind the scenes that needs to be taken care of as well, whether it’s fuel infrastructure to keep the car running, a semiconductor manufacturer to create silicon wafers, or a control system for the robot. This project is one of the latter: a human interface device for a robot arm that is completely DIY.
While robots are often automated, some still need human input. …read more
Here’s a rec-room ready hack: an automatic drink dispenser.
[truebassB]’s dispenser operates around a 555 timer, adjusted by a potentiometer. Push a button and a cup pours in a few seconds, or hold the other button to dispense as much as you want.
The dispenser is made from MDF and particle board glued together, with some LEDs and paper prints to spruce it up. Just don’t forget a small spill sink for any miscalculated pours. You needn’t fret over the internals either, as the parts are easily acquired: a pair of momentary switches, a 12V micro air pump, a brass …read more
Deep in the bowels of the Digikey and Mouser databases, you’ll find the coolest component ever. Motorized linear potentiometers are a rare, exotic, and just plain neat input device most commonly found on gigantic audio mixing boards and other equipment that costs as much as a car. They’re slider potentiometers with a trick up their sleeve: there’s a motor inside that can set the slider to any position.
The mechanical keyboard community has been pushing the boundaries of input devices for the last few years, and it looks like they just discovered motorized linear pots. [Jack] created a motorized sliding …read more
Continue reading Wherein The Mechanical Keyboard Community Discovers Motorized Linear Potentiometers
If you’re looking for a high entertainment value per byte of code, [Nardax] has you covered with his wearable spellcasting controller. With not much effort, he has built a very fun looking device, proving what we’ve always known: a little interaction can go a long way.
[Nardax] originally intended his glorified elbow-mount potentiometer to be a fireworks controller. Ironically, he’s now using it to throw virtual fireballs instead. Depending on the angle at which he holds his elbow before releasing it, he can cast different spells in the game World of Warcraft. We’re not at all sure that it helps …read more
Continue reading Hackaday Prize Entry: [Nardax] Shoots Fireballs
Problem: build a combined anemometer and wind vane where the pivots for both sensors are coaxial. Solution: turn an old universal motor into a step-wise potentiometer for the wind vane, and then pull a few tricks to get the whole thing assembled.
We have to admit that when we first saw [Ajoy Raman]’s Instructables post, we figured that he used a universal motor to generate a voltage from the anemometer. But [Ajoy]’s solution to the coaxial shafts problem is far more interesting than that. A discarded universal motor donated its rotor and bearings. The windings were stripped off the assembly …read more
Continue reading Old Motor Donates Rotor for Coaxial Wind Vane and Anemometer
If you have a traditional regulated power supply that you want to make adjustable, you’ll have somewhere in the circuit a feedback line driven by a potential divider across the output. That divider will probably incorporate a variable resistor, which you’ll adjust to select your desired voltage.
The problem with using a standard pot to adjust something like a power supply is that a large voltage range is spread across a relatively small angle. The tiniest movement of the shaft results in too large a voltage change for real fine-tuning, so clearly a better means of adjustment is called for. …read more
The Wheatstone bridge is a way of measuring resistance with great accuracy and despite having been invented over 150 years ago, it still finds plenty of use today. Even searching for it on Hackaday brings up its use in a number of hacks. It’s a fundamental experimental device, and you should know about it.
Here’s an easy way to understand how the Wheatstone bridge works. In the schematic are two voltage dividers (pairs of resistors in series): R1 with R2 and R3 with R4. If you do the math, you’ll notice that the voltages across R1 and …read more
Adjusting the volume dial on a sound system, sensing your finger position on a touch screen, and knowing when someone’s in the car are just a few examples of where you encounter variable resistors in everyday life. The ability to change resistance means the ability to interact, and that’s why variable resistance devices are found in so many things.
The principles are the same, but there are so many ways to split a volt. Let’s take a look at what goes into rotary pots, reostats, membrane potentiometers, resistive touchscreens, force sensitive resistors, as well as flex and stretch sensors.
Continue reading Resistance in Motion: What You Should Know About Variable Resistors
