https://community.element14.com/products/manufacturers/tdk/w/documents/10428/low-cost-power-supplies-can-be-expensiveen-USTelligent Community 12https://community.element14.com/products/manufacturers/tdk/w/documents/10428/low-cost-power-supplies-can-be-expensiveFri, 08 Oct 2021 05:12:34 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e56529cd-e6f5-4280-b723-83f644eee49bNortskihttps://community.element14.com/products/manufacturers/tdk/w/documents/10428/low-cost-power-supplies-can-be-expensive#commentsCurrent Revision posted to Documents by Nortski on 10/8/2021 5:12:34 AM<br /> <p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">Recently, one of our Field Application Engineers came into my office to show me an AC-DC adapter/power supply he had purchased on-line.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">“I paid $6.00 for this power supply.&nbsp; It has selectable outputs and multiple connectors, he proudly announced.&nbsp; How do they build it for such a low price?” he asked.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p class="separator" style="margin:0;margin:0 0 0.75em;font-family:Verdana, Arial, sans-serif;text-align:center;"><a href="http://us.tdk-lambda.com/lp/images/2012-07-wallplug.png" rel="nofollow ugc noopener" style="color:#336699;margin-left:1em;margin-right:1em;" target="_blank"><img alt="image" border="0" class="jiveImage" height="240" src="http://us.tdk-lambda.com/lp/images/2012-07-wallplug.png" style="border-color:#cccccc;padding:4px;" width="320" /></a></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">I was a little suspicious as it did not seem to have a UL logo, and judging by the weight of the adapter, it was a linear (not switch-mode), which may violate the off load power draw requirements in the US.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">“Don’t leave it plugged-in when you leave the house” was my advice.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">The next day he came back into my office and said:</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">“I set the output voltage to 4.5V and it powered up my digital camera just fine.&nbsp; After I finished down loading my photographs, the camera went into standby mode and stopped working (permanently).”</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">When tested, the adapter would regulate under load, but at light loads, the output rose to from 4.5V to 12V.&nbsp; Of course, when the camera went into sleep mode it drew very little power and the resulting unforeseen 12V output fried the camera’s circuitry.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">Now, looking at the attached photograph, I see that the manufacturer misspelled “Adapter”, which should have been a clue regarding the low quality of this unit.</span></p><p style="margin:0;"><br style="font-family:Verdana, Arial, sans-serif;" /></p><p style="margin:0;"><span style="font-family:Verdana, Arial, sans-serif;">“Sorry, you got what you paid for my friend” I commented.</span></p><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: ac/dc, quality, cheap, low_cost, power_supply</div>