Here are a few quick tips on specifying the right power supply for your application.
Is your power supply going to be exposed to the elements? Indoor or outdoor you need to consider both low and high temp ranges. Let’s start with the low temp side. Once started, most power supplies can handle very low temperatures since they are self-heating by nature. However, as you get below 0°C, lower effective capacitance begins to decrease the power supply's ability to start. When you get below -20°C the switching chip may refuse to work as well.
Fortunately we offer many models that start at lower temperatures. For those applications where we can't reach the low limit, we can suggest external heating circuits that will warm the supply until it comes up to temperature.
→Far more often it is the high temperature that is of concern. Every power supply has to be cooled either by air or conduction. For convection or forced air applications, an unrestricted path is the best way to make sure the power supply remains cool and performs to specification. In the real world applications often have space restraints, so unrestricted paths for cooling are sometimes impossible. When thermal considerations and space collide there is no substitute for heat testing. In most cases we can find the critical thermal points in a power supply from the manufacturer. After we get the component-specific maximum temperature recommendations, a test with the power supply installed in its designated home under the worst temperature and duty cycle conditions will demonstrate how close the supply is from its terminal temperature. This test is accomplished with thermocouples and/or infrared thermometers.
What’s more, you can now experiment with moving the power supply and other components around to try and direct the airflow properly. If you are unable to keep the power supply from thermal melt down you might consider increasing the power supply rating to one with a higher temperature range. If this is not readily available increasing to the next higher power range may accomplish the same thing. For instance, if you are unable to keep your 240 watt power supply cool enough in a 60C environment, try upgrading to a 320 watt. All of the components in the 320 watt are designed to handle 320 watts and will run considerably cooler at 240 watts.
What about extra fans? Extra fans are an option to increase the air flow for cooling; however you must always bear in mind the life expectancy of fans is considerably lower than solid state components. Therefore when using auxiliary cooling fans you should use conservative figures and only operate the fan when thermal conditions require it. For more information, give us a call. We will be glad to brainstorm your application.
Read More Knowledgebase Articles on power supplies at peaktopeakpower.com
Learn more on currentsolutions.com
No comments:
Post a Comment