Diode Current Question. - Page 1
Forum section: electronics / beginners

author: neo
author_rank: Super Contributor
timestamp: May 14, 2017, 07:33:17 pm
content: If i have a diode rated for 10 amps at 1000 volts, which i do, does the maximum current change with voltage? Lets assume for the purpose of this question that the diodes are attached to large hunk of aluminum to serve as a heat sink.

author: Ghydda
author_rank: Regular Contributor
timestamp: May 14, 2017, 08:13:55 pm
content: Quote from: neo on May 14, 2017, 07:33:17 pmI am not sure you are asking an answerable question.The rating af a 1000 volt surely relates to the devices ability to withstand a reverse voltage, and the rating of 10 amps surely relates to the current carrying ability, while biased in a forward voltage situation.Kinda an apples and oranges situation.Sendt fra min Nexus 6 med Tapatalk

author: neo
author_rank: Super Contributor
timestamp: May 14, 2017, 08:25:07 pm
content: http://pdf1.alldatasheet.com/datasheet-pdf/view/190269/WTE/10A10.htmlthis is the diode i have and i just want to know if current is, as they rate it, relative to voltage or not.

author: TimFox
author_rank: Super Contributor
timestamp: May 14, 2017, 08:37:42 pm
content: The data sheet is explicit. The average forward ("rectified") current must be less than 10 A under the specified temperature conditions. The voltage will depend on the junction temperature, but that is included in the specification. The reverse current specification is a performance condition, giving the maximum current under specified reverse-bias conditions.When reading specifications, one must avoid the temptation to assume that every single value applies simultaneously. For example, there should never be 1000 V offorwardbias on such a diode.

author: MagicSmoker
author_rank: Super Contributor
timestamp: May 14, 2017, 09:39:16 pm
content: Quote from: neo on May 14, 2017, 08:25:07 pmThe 1000V rating describes what the diode can block or withstand in the reverse direction, so, no, the current rating doesn't go up if the reverse voltage applied to the diode goes down.

author: jeroen79
author_rank: Frequent Contributor
timestamp: May 14, 2017, 09:42:21 pm
content: Quote from: neo on May 14, 2017, 08:25:07 pmThe I-V curve for your diode is specified in the datasheet.Mind that the vertical I axis is logarithmic and the horizontal V axis is linear.Also note that is is for a temperature of 25 degrees celsius.Keep in mind that for a diode like this the voltage usually is the result of the current passed through it (limited by something else) rather than the other way around.It's current rating is related to the diode's abilty to withstand high temperature and dissipate heat.As it is it can safely pass 10 Amperes at a temperature of 50 degrees.If you improve the diode's cooling (improved airflow, big heat sink, liquid nitrogen) then you can probably put more current through it.But you'll have to figure that out yourself, the manufacturer is not giving any guarantees here.If you need to pass more current in your specific application, just get a different diode.If this is not what you want to know then you will need to rephrase your question.

author: neo
author_rank: Super Contributor
timestamp: May 14, 2017, 10:54:41 pm
content: Quote from: jeroen79 on May 14, 2017, 09:42:21 pmNo actually that is the perfect answer, exactly what i was looking for and more.