humidifier

3 Articles

3D-Printed RC Drift Car Comes With Smoke Effects

July 25, 2024 by 7 Comments

Drift cars are cool, but they’re also expensive. If you don’t have money for endless tires, fuel, and engine rebuilds, you might like to get involved at the RC scale instead. [Max Imagination] has just the build to get you started.

The design uses 3D printing for the majority of the chassis. Rigidity is front of mind, as is creating the right  steering and suspension geometry for smooth, controllable drifts. The drivetrain is 3D-printed too, using plastic gears and universal-joint axles combined with off-the-shelf bearings. Steering is controlled via an off-the-shelf servo, with a brushless motor putting power down to all four wheels. While drifting at full scale is best achieved with rear-wheel-drive, it’s easier to control at the small scale with four driven wheels.

True to the DIY ethos, an Arduino-based RC system is used to drive the steering servo and motor speed controller, with a home-built pistol-grip controller. It also activates a small power supply which runs little humidifier modules, which turn water into a visible vapor for a fun smoke effect. It doesn’t really imitate tire smoke, since it disappears nearly the instant the car moves, but it’s still a neat effect.

It’s a neat build that makes a great starting point for your dive into RC. Meanwhile, if you’re more about speed than getting sideways, we’ve seen a homebrew RC car designed to that end as well. Video after the break. Continue reading “3D-Printed RC Drift Car Comes With Smoke Effects” →

Cool Off With A Piezo And A Glass Of Water

August 21, 2020 by 21 Comments

Some cool-mist humidifiers work by flinging water at a vaporizer, but our favorite kind uses a piezoelectric transducer. These work by using high-frequency sound waves to pound the surface of the water with mechanical energy. That energy introduces standing waves that force the water to break apart into a fine mist on the surface of the piezo disk.

The driving circuit for this DIY mist maker uses a 555 to generate 113 KHz, a trimmer potentiometer to fine-tune it, and a MOSFET to amplify the signal. You don’t need much more than that and a handful of passives to recreate this cool junk box experiment, but the spec of the piezo disk is quite important. The circuit is designed for atomizing transducers, which have a resonant frequency of 113 KHz — much higher than your average junk box piezo. Check out the demo and build video after the break.

Atomizing transducers can do way more than than moisten the air for our comfort. They’re not picky about where the water comes from, so if you have enough of them, you can dry a load of laundry in a few minutes.

Continue reading “Cool Off With A Piezo And A Glass Of Water” →

Hackaday Prize Entry: CPAP Humidifier Monitor Alarm

August 25, 2017 by 31 Comments

CPAP (Continuous Positive Airway Pressure) machines can be life-changing for people with sleep apnea. [Scott Clandinin] benefits from his CPAP machine and devised a way to improve his quality of life even further with a non-destructive modification to monitor his machine’s humidifier.

With a CPAP machine, all air the wearer breathes is air that has gone through the machine. [Scott]’s CPAP machine has a small water reservoir which is heated to humidify the air before it goes to the wearer. However, depending on conditions the water reservoir may run dry during use, leading to the user waking up dried out and uncomfortable.

To solve this in a non-invasive way that required no modifications to the machine itself, [Scott] created a two-part device. The first part is a platform upon which the CPAP machine rests. A load cell interfaced to an HX711 Load Cell Amplifier allows an Arduino Nano to measure the mass of the CPAP machine plus the integrated water reservoir. By taking regular measurements, the Arduino can detect when the reservoir is about to run dry and sound an alarm. Getting one’s sleep interrupted by an alarm isn’t a pleasant way to wake up, but it’s much more pleasant than waking up dried out and uncomfortable from breathing hot, dry air for a while.

The second part of the device is a simple button interfaced to a hanger for the mask itself. While the mask is hung up, the system is idle. When the mask is removed from the hook, the system takes measurements and goes to work. This makes activation hassle-free, not to mention also avoids spurious alarms while the user removes and fills the water reservoir.

Non-invasive modifications to medical or other health-related devices is common, and a perfect example of nondestructive interfacing is the Eyedriveomatic which won the 2015 Hackaday Prize. Also, the HX711 Load Cell Amplifier has an Arduino library that was used in this bathroom scale refurb project.

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