May 14, 2020, 12:24 p.m.
12V 10A SMPS Review and Teardown
I ordered 12V 10A 120W SMPS from Shopee, amid the Enhanced Community Quarantine (ECQ) it arrived earlier than I expected. Ninjavan delivered it using Cash On Delivery but due to some circumstance, they are stuck at some place. I went to that place to pickup and paid the order.
The package was bubble wrapped, it has a box. Upon opening the box, the SMPS appears to be an old stock. There are scratches, a part was deformed and the ‘Inspection Sticker’ was already torn. Maybe somebody tried to remove the cover of the power supply. The stickers does not have dust, so it must be an old stock. The sticker has the date 2017-08.
For the price of Php 380 including shipping, it is ok. I did not expect that the module was this big, it looks like not rated for 10A but more than 10A.
The PCB of the board has a marking of 250, maybe it is a relabeled product? Maybe this SMPS has a rating of 12V 250 Watts? According to diodegonewild, this SMPS is a half-bridge topology and not flyback. You can watch his video about a similar SMPS that I have here though his SMPS is 24V: https://invidio.us/watch?v=KIilQrgJ-gg
The SMPS has two DC outputs labeled V- and V+., AC input L, N and GND. You can adjust the output voltage by rotating the trimpot near the green LED, the voltage output ranges from 10V to 14.8V.
The circuit board:
The two D13009K NPN Bipolar power transistors:
The other yet-to-be-indenfified double diode was mounted without thermal paste. So, I added thermal paste and mounted it correctly.
KA7500 SMPS Controller IC:
Idle power consumption is around 8 watts.
220V x 0.04A = 8.8W
I plan to use this SMPS to power my DIY Uninterruptible DC Power Supply for powering Raspberry Pi 3B+ and HP Thin Client T610 (once I have acquired a DC Boost Converter and 7.4x5.00mm DC Jack for T610).
Credits to DiodeGoneWild for his great explanation of how SMPS works, visit his site at: http://danyk.cz and his channel at: https://invidio.us/channel/UCQak2_fXZ_9yXI5vB_Kd54g
The SMPS inside my DIY UPS with Raspberry Pi 3B+, XL4015, LM2596, MP1584, 12V FAN, 12V Sealed Lead Acid Battery and bunch of wires.:
Video demo (Youtube and Peertube):
https://peertube.social/videos/watch/4ae7204d-4ec7-451b-831f-064e86648e64