I've mentioned previously about the Hiland LCD PSU kit from Banggood, well I've finally got it finished!
My last 'problem' was sourcing a suitable mains transformer for it, as they tended to be too large, or too expensive - eventually I opted for a 24V 4-6A SMPSU board from Banggood, at a fraction of the price of a transformer. I modified the PSU (by simply adding a resistor to the feedback network) to convert it to 30V DC out - the PSU kit calls for either 24V AC from a transformer, or a 30V DC supply. I saw no point in feeding the DC through the bridge rectifier, so I wired the 30V directly to the reservoir capacitor.
It's particularly nice to use, as you set the voltage and current via rotary encoders, and pressing the controls stores the settings to remember it next time you turn on.
I have noticed that inexpensive Chinese variable supplies have poor protection from non-linear (stripLED) overload. In my case 3 x 5 m stripleds with tiny LEDs. Both failed catastrophically in less than a week. Perhaps driven to or beyond the rated current limit.
Banggood and a few other Chinese places copied the defective Greek Kit that I talked about and fixed 15 years ago at www.electronics-lab.com because it had many overloaded parts and failed soon. Here is another website that copied the problems I found with this kit:
After assembling the Hiland avr psu. I noticed that stability was poor. I fixed the issue by replacing the 22n to a 100nf capacitor on the transistor board and also wire an optocoupler on the base on the transistor which the avr drives the voltage.
Also across the 5v Zener, I added another 100nf to smooth any spikes entering the avr.
Looks like I'll be placing an order with banggood unless someone confirms Audios comment about it being flawed. The one with the LCD appears to be a more recent design with an AVR.
Looks like I'll be placing an order with banggood unless someone confirms Audios comment about it being flawed. The one with the LCD appears to be a more recent design with an AVR.
Only US$20.99, buy best 0-28V 0.01-2A Adjustable DC Regulated Power Supply Module DIY Kit Short Circuit Current Limiting Protection sale online store at wholesale price.
I see that Banggood sells clothing, shoes and many power supply kits.
Your kit has no detailed spec's and in Chinglish they say, "please be sure to carefully" so you better watch out!