You may have seen the Ruideng range of programmable power supply modules from China: small and relatively inexpensive switch-mode buck converters, with microprocessor control and a front panel featuring a large colour OLED screen. Given 30 volts or so they can supply any lower voltage with the extra bonus of current limiting. They’ve been so successful over the several years they’ve been available that they’ve even spawned their own Chinese clones, and countless hacker projects, for instance on the DPS300X and DPS500X models.
Late last year a new module came from Ruideng, the Riden-branded RD6006 combines the basic idea of the previous modules with an extremely flexible front panel with full keypad and rotary encoder, creating something like the front panel to a decent bench power supply but without the accompanying power supply. I ordered one, waited for it to clear customs, took it to my bench, and reviewed it. Continue reading “Review: The Riden RD6006W DC Power Supply Module”
One of the challenges of keeping a vintage computer up and running is the limited availability of spare parts. While not everything has hit dire levels of availability (not yet, anyway), it goes without saying that getting a replacement part for a 30+ year old computer is a bit harder than hitting up the local electronics store. So the ability to rebuild original hardware with modern components is an excellent skill to cultivate for anyone looking to keep these pieces of computing history alive in the 21st century.
This is in ample evidence over at [Inkoo Vintage Computing], where repairs and upgrades to vintage computers are performed with a nearly religious veneration. Case in point: this detailed blog post about rebuilding a dead Amiga 500 power supply. After receiving the machine as a donation, it was decided to attempt to diagnose and repair the PSU rather than replace it with a newly manufactured one; as much for the challenge as keeping the contemporary hardware in working order.
What was found upon opening the PSU probably won’t come as a huge surprise to the average Hackaday reader: bad electrolytic capacitors. But these things weren’t just bulged, a few had blown and splattered electrolyte all over the PCB. After removing the bad caps, the board was thoroughly inspected and cleaned with isopropyl alcohol.
[Inkoo Vintage Computing] explains that there’s some variations in capacitor values between different revisions of the Amiga PSU, so it’s best to match what your own hardware had rather than just trying to look it up online. These capacitors in particular were so old and badly damaged that even reading the values off of them was tricky, but in the end, matching parts were ordered and installed. A new fuse was put in, and upon powering up the recapped PSU, the voltages at the connector were checked to be within spec before being plugged into the Amiga itself.
As a test, the Amiga 500 was loaded up with some demos to really get the system load up. After an hour, the PSU’s transformer was up to 78°C and the capacitors topped out at 60°C. As these parts are rated for 100°C (up from 85°C for the original parts), everything seemed to be within tolerances and the PSU was deemed safe for extended use.
This sort of repair isn’t exactly rare with hardware this old, and we’ve seen similar work done on a vintage Apple power supply in the past. If you’re less concerned with historical accuracy, [Inkoo Vintage Computing] has also shown off adapting an ATX PSU for use with the Amiga.
Over the years, computers have become faster, but at the same time, more power hungry as well. Way back around the 386 era, most PCs were using the AT standard for power supplies. Since then, the world moved on to the now ubiquitous ATX standard. Hobbyists working on older machines will typically use these readily available supplies with basic adapters to run old machines, but [Samuel] built a better one.
Most AT to ATX adapters are basic passive units, routing the various power lines where they need to go and tying the right pin high to switch the ATX supply on. However, using these with older machines can be fraught with danger. Modern supplies are designed to deliver huge currents, over 20 A in some cases, to run modern hardware. Conversely, a motherboard from the early 90s might only need 2 or 3A. In the case of a short circuit, caused by damage or a failed component, the modern supply will deliver huge current, often damaging the board, due to the overcurrent limit being set so high.
[Samuel]’s solution is to lean on modern electronics to build an ATX to AT adapter with programmable current protection. This allows the current limit to be set far lower in order to protect delicate boards. The board can be set up in both a “fast blow” and a “slow blow” mode to suit various working conditions, and [Samuel] reports that with alternative cabling, it can also be used to power up other old hardware such as Macintosh or Amiga boards. The board is even packed with extra useful features like circuitry to generate the sometimes-needed -5V rail. It’s all programmed through DIP switches and even has an OLED display for feedback.
It’s an adapter that could save some rare old hardware that’s simply irreplaceable, and for that reason alone, we think it’s a highly important build. We’ve talked about appropriate fusing and current limiting before, too – namely, with LED strips.
Everyone needs a bench power supply, and rolling your own has almost become a rite of passage for hackers. For a long time, the platform of choice for such builds seemed to be the ATX power supply from a computer. While we certainly still see those builds, a lot of the action has switched to those cheap eBay programmable DC-DC converters, with their particolored digital displays.
This hybrid bench and portable power supply is a good example of what can be accomplished with these modules, and looks like it might turn out to be a handy tool. [Luke] centered his build around the DPS3003, a constant current and constant voltage buck converter that can take up to 40-VDC input and outputs up to 32 volts at 3 amps. In bench mode, the programmable module is fed from a mains-powered 24-volt switching supply. For portable work, an 18-volt battery from a Makita drill slips into a 3D-printed adapter on the top of the case. The printed part contains a commercial terminal [Luke] scored on eBay, but we’d bet the entire thing could be 3D printed. And no problem if you change power tool brands — just print another adapter.
Those little eBay power supply modules have proven to be an enabling technology, at least judging by the number of clever ways we’ve seen them used lately. From this combination bench PSU and soldering iron supply to a portable PSU perched atop a battery, these things are everywhere. Heck, you can even reflash the firmware and make them do your bidding.
[via Dangerous Prototypes]
Say what you want about the current crop of mass-marketed consumer-grade cordless tools, but they’ve got one thing going for them — they’re cheap. Cheap enough, in fact, that they offer a lot of hacking opportunities, like this portable bench power supply that rides atop a Ryobi battery.
Like many of the more common bench supply builds we’ve seen, [Pat K]’s more portable project relies on the ubiquitous DPS5005 power supply module, obtained from the usual sources. [Pat K] doesn’t get into specifics on performance, but supplied with 18 volts from a Ryobi One+ battery, the DC-DC programmable module should be able to do up to about 16 volts. Mating the battery to the supply is easy with the 3D-printed case, which has a socket for the battery that mimics the sockets on tools from the Ryobi line. It’s simple and effective, as well as neatly executed. The files for the case are on Thingiverse; sadly, only an STL file is included, so if you want to support another brand’s batteries, you’ll have to roll your own.
Check out some of the other power supplies we’ve featured that use the DPS5005 and its cousins, like this nice bench unit. We’ve also covered some of the more hackable aspects of this module, such as an open-source firmware replacement.
Just because something is “never used” doesn’t mean it’s good. [Inkoo Vintage Computing] learned that lesson while trying to repair an Amiga 500 and finding parts online that were claimed to be “new” in that they were old stock that had never been used. The problem was that in the last 30 years the capacitors had dried out, rendering these parts essentially worthless. The solution, though, was to adapt a modern PSU for use on the old equipment.
The first hurdle to getting this machine running again was finding the connector for the power supply. The parts seemed to have vanished, with some people making their own from scratch. But after considering the problem for a minute longer they realized that another Commodore machine used the same parts, and were able to source a proper cable.
Many more parts had to be sourced to get the power supply operational, but these were not as hard to come across. After some dedicated work with the soldering iron, the power supply was put to use running the old Amiga. Asture readers will know that [Inkoo Vintage Computing] aren’t strangers to the Amiga. They recently were featured with a nondestructive memory module hack that suffered from the same parts sourcing issues that this modification had, but also came out wonderfully in the end.
Modern LED strips are magical things. The WS2812 has allowed the quick and easy creation of addressable RGB installations, revolutionizing the science of cool glowy things. However, this accessibility means that it’s easy to get in over your head and make some simple mistakes that could end catastrophically. [Thomas] is here to help, outlining a common mistake made when building with LED strips that is really rather dangerous.
The problem is the combination of hardware typically used to run these LED strings. They’re quite bright and draw significant amounts of power, each pixel drawing up to 60 mA at full-white. In a string of just 10 pixels, the strip is already drawing 600 mA. For this reason, it’s common for people to choose quite hefty power supplies that can readily deliver several amps to run these installations.
It’s here that the problem starts. Typically, wires used to hook up the LED strips are quite thin and the flex strips themselves have a significant resistance, too. This means it’s possible to short circuit an LED strip without actually tripping the overcurrent protection on something like an ATX power supply, which may be fused at well over 10 amps. With the resistance of the wires and strip acting as a current limiter, the strip can overheat to the point of catching fire while the power supply happily continues to pump in the juice. In a home workshop under careful supervision, this may be a manageable risk. In an unattended installation, things could be far worse.
Thankfully, the solution is simple. By installing an appropriately rated fuse for the number of LEDs in the circuit, the installation becomes safer, as the fuse will burn out under a short circuit condition even if the power supply is happy to supply the current. With the example of 10 LEDs drawing 600 mA, a 1 amp fuse would do just fine to protect the circuit in the event of an accidental short.
It’s a great explanation of a common yet dangerous problem, and [Thomas] backs it up by using a thermal camera to illustrate just how hot things can get in mere seconds. Armed with this knowledge, you can now safely play with LEDs instead of fire. But now that you’re feeling confident, why not check out these eyeball-searing 3 watt addressable LEDs?
Continue reading “The Engineering Case For Fusing Your LED Strips”