Tag Archives: DIY

A passive tunable HF preselector

via Dangerous Prototypes

Dave Richards (AA7EE) has written an article detailing his tunable passive HF preselector:

When I built the VE7BPO DC Receiver Mainframe recently, it wasn’t intended to end up as a final finished project. The intention was more to have it as part of an experimental platform. The little box that contains the DBM, diplexer, and AF amplifier that make up the mainframe will most likely stay largely the same, now that they are built and boxed up. However, the outboard functions of local oscillator and antenna filtering can swapped around and changed at will. The mainframe includes a spot for an onboard plug-in bandpass filter.

See the full post on his blog.

MetaClockClock build

via Dangerous Prototypes

Erich shared detailed instructions of how to build the MetaClockClock project, a set of individual analog ‘clocks’:

The ‘MetaClockClock’ project is using multiple small dual-shaft stepper motors which are usually used in instrumentation clusters. In this project multiple such motors are interconnected on a RS-485 bus and can be controlled by a master to display information or show different animation patterns.

Check out the video after the break.

Project info at mcuoneclipse.com. Files are available on GitHub.

Lab power supply build using old power bricks

via Dangerous Prototypes

Building a lab power supply from old computer power bricks:

Over the years, I have accumulated many used computer power bricks. Although I could just use them by themselves to power other electronics with similar voltage and current requirements, I thought I would combine a few of them together as the input to a linear regulator so that I can make a powerful lab power supply.

See the full post on Kerry Wong’s blog.

DIY current sensor capable of handling up to 15A

via Dangerous Prototypes

Utsav shared detailed instructions of how to build your own current sensor that can measure up to 15 Amps, project instructables here:

This current sensor can easily be used for measuring currents up to 15 Amps constant and can even handle about 20 Amps peak. I had previously built a shunt current measurement module using a home made shunt but it had a few limitations- The wire was quite long which may not be suitable for small devices. It also got rusted over time and one major drawback was heating at higher currents even at 10 amperes. Well, this module solves almost all of these problems in a more efficient design.

Check out the video after the break.

Building a DIY High density Philips Hue LED stripe

via Dangerous Prototypes

Erich created a DIY high density Hue smart LED stripe:

Philips Hue Smart LED stripes are great, but they have a disadvantage: the LED density is rather low: one LED cluster (WW, RGB, CW) every 55 mm. This leads to the problem that individual dots might be visible if the LED stripe is directly visible. Even if the LED stripe is used for indirect ambient light it means that individual dots might still be visible on the wall or ceiling. The solution is to create a ‘high density’ Hue smart LED stripe

More details on MCU on Eclipse blog.