Greetings,
I have some ultra fast soft recovery diodes in TO-220 package that I would like to use to reduce the PS noise (hash) threshold in an amplifier currently using two (2) bridge rectifiers for a split B+; i.e., +/- 220V dc. There are some FRED soft recovery bridge rectifiers available however at a cost I would like to avoid.
The amp at idle draws 200 ma per PS rail through each bridge rectifier for a total of 400 ma.
I figure 300 ma including power up current surge at 220V rectified output would result in 66 W in each bridge. Would it then be correct to provide 17 Watt of heat-sinking per diode, since I would be using 4 diodes to replace each bridge? Or should I consider the AC input to compute the heat-sinking requirements? Or should the heat-sink size be based on the specified maximum allowable temperature of the diode junction?
The diodes I will be using are: http://www.fairchildsemi.com/ds/IS/ISL9R1560PF2.pdf
I realize that the PD of this diode is specified at 30W but I am not sure if that is with or without a heat-sink. The TO-220 package should provide some inherent heat-sinking due to the tab used in its construction.
Anyhow I thought I would pose the question to the more experienced fellows to be on the safe side and minimize unnecessary work.
Thanks in advance.
I have some ultra fast soft recovery diodes in TO-220 package that I would like to use to reduce the PS noise (hash) threshold in an amplifier currently using two (2) bridge rectifiers for a split B+; i.e., +/- 220V dc. There are some FRED soft recovery bridge rectifiers available however at a cost I would like to avoid.
The amp at idle draws 200 ma per PS rail through each bridge rectifier for a total of 400 ma.
I figure 300 ma including power up current surge at 220V rectified output would result in 66 W in each bridge. Would it then be correct to provide 17 Watt of heat-sinking per diode, since I would be using 4 diodes to replace each bridge? Or should I consider the AC input to compute the heat-sinking requirements? Or should the heat-sink size be based on the specified maximum allowable temperature of the diode junction?
The diodes I will be using are: http://www.fairchildsemi.com/ds/IS/ISL9R1560PF2.pdf
I realize that the PD of this diode is specified at 30W but I am not sure if that is with or without a heat-sink. The TO-220 package should provide some inherent heat-sinking due to the tab used in its construction.
Anyhow I thought I would pose the question to the more experienced fellows to be on the safe side and minimize unnecessary work.
Thanks in advance.