Nabbed one of these and am quite happy with it. Works with 110/220 natively so no chance of non-region live input.
Singpad New Style LED Power Supply https://www.amazon.com/dp/B00N2PRMWY/ref=cm_sw_r_awd_-fWpvb1ZXMBQC
Usual issues I encounter with these sorts of supplies are AC ripple on the DC under load (which LEDs don’t really care about too much), and occasionally not starting cleanly (no output at all).
AC ripple…had to google that. What negative effects can it cause?
Well if the AC ripple happens at the right time (like when there is a ground bounce due to a stepper driver turning ‘off’ briefly) it can cause the CPU to think there is a brown out and reset itself.
Varying power might undervolt important circuits. You might experience part quality issues or get unreliable/erratic operation. You might be OK. Stepper drivers can handle it, though top end motor performance might be affected. The heaters can handle it. Your controller board is probably separate power supply or a second stage so you’d need serious AC issues if it gets to your controller board. I’m sure I’m missing some other possible side effects.
@Stuart_Young I’m curious. How does AC ripple find its way onto the dc side when the typical operating frequency of an SMPS is at least 50 kHz?
@Chengster_N It happens when your power draw exceeds the conversion circuitry’s ability to keep up.
Alright, that’s enough to convince me to swap back. Thanks for the knowledge!
@Jeff_DeMaagd I see. I was under the impression that overload protection is generally part of the specs of your typical smps controller chip and therefore the psu should shut down when this happens?
Well, it’s a bit complicated. LEDs aren’t very demanding on the ripple, so you don’t need as rigorous of a power supply in smoothing out those ripples. So you can get away with smaller capacitors, for example. It doesn’t mean that the power supply is at risk of damage.
Whether it’s a serious problem or not for a DIY machine really depends. Sometimes decently serviceable enclosed power supplies are sold as ‘LED’ power supplies anyway.
To be specific, it’s not 50 Hz AC ripple. It’s an AC signal imposed on top of the DC, usually high frequency, that produces a similar effect. In some of the really cheap SMPS supplies, this can get as high as 10% of the DC supply under heavy (near full) load. There is usually ripple of some sort in most SMPS outputs (even PC PSUs), and it’s just a matter of being aware of it and catering for it.
Any noise on the DC supply means that the filtering isn’t keeping up with the current draw. As mentioned, on LEDs this isn’t too much of a problem (you won’t really notice a 50kHz signal in LEDs), but electronic circuitry (eg: Some sort of processor) can be quite susceptible to noise that causes all sorts of false triggers, events and the like. Even things as innocuous and simple as thermistor inputs and end stops can have issues with such noise bleeding through through the system causing all sorts of weird behavior.
A simple filter on any of the lower drawing current parts of the electronics (eg: the processing part) goes a long way toward avoiding this being an issue. Many simple regulator circuits can be quite capable of doing this, but many of the 3D electronics designs out there either don’t do it, or don’t do it well enough to stop some of that noise bleeding through and causing all sorts of issues.
FWIW: Using the regulator on Arduino based systems (eg: the way RAMPS does) isn’t any better, as most Arduino boards aren’t very forgiving of noisy supplies.
@Ben_Van_Den_Broeck I have a similar sort of supply myself (24V in my case) and it works quite well. It’s just something to keep in mind so that if you run up against a problem, you have some ideas on what to do and/or what needs to be done to solve the problem. A lot of people have an issue like that and just assume they got a dud and throw it out, when a small amount of work can solve the problem.
Not a “Do not buy”, more a “Be wary but not alarmed”. Sorry if I spooked you.
I just got a similar 24V supply that I want to try in my next build.
No worries @Stuart_Young , I ain’t getting rid of the one I got just yet. Just not switching over my next few 