Dear All
I would like to know for a Single phase bridge reactifier - GBPC2502 with power rating 25A , does it mean that "each" diode within is handling 25A or just 25/4 that is @6A , I wish to replace the bridge doide with 4 single piece of fast recovery diode each with power rating of only 5A , is that safe to do it in my 200W power amp. ? Thanks in advance .
Larry
I would like to know for a Single phase bridge reactifier - GBPC2502 with power rating 25A , does it mean that "each" diode within is handling 25A or just 25/4 that is @6A , I wish to replace the bridge doide with 4 single piece of fast recovery diode each with power rating of only 5A , is that safe to do it in my 200W power amp. ? Thanks in advance .
Larry
As DF96 says whether a 5A diode is suitable for your amp is a separate issue, my gut feeling is that the answer will be no, but it will depend a lot on the type of amplifier and the size of the capacitors in the power supply.
You might want to consider something like the BYV32-E diodes BYV32E-200 - NXP - DIODE, ULTRAFAST, 2X10A | element14 Australia If you use four for a bridge and short pins 1 and 3 of each to run the dual diodes in parallel you get 20A per diode capacity. Recovery time is 25ns which is pretty good! There are higher current versions as well with slightly slower recovery time.
Tony.
You might want to consider something like the BYV32-E diodes BYV32E-200 - NXP - DIODE, ULTRAFAST, 2X10A | element14 Australia If you use four for a bridge and short pins 1 and 3 of each to run the dual diodes in parallel you get 20A per diode capacity. Recovery time is 25ns which is pretty good! There are higher current versions as well with slightly slower recovery time.
Tony.
Thanks DF96 , I obtained some IR 50SQ100 and I replaced the bridge diode in my 45W rating Exposure mono block amp and it sounds very good indeed so I think of doing the same in my BAT amp with power rating of 200W but I am worrying that it will not able to handle the current required as IR is only with 5A rating , can I parallel 2 IR as one and use 8 pcs. as one bridge rectifier to replace the GBPC 2502 ? Still only 10A but with 40000uf of reserve behind , would it be OK ?
Am I correct if the diode is not very hot to the touch during working = it is able to supply the current required .
Thanks again !
Am I correct if the diode is not very hot to the touch during working = it is able to supply the current required .
Thanks again !
Here is the output of a very basic PS simulation using LTspice. Series resistance of the voltage sources set to 0.5 ohms (which is probably a bit low, and the initial peak current would come down a bit if this were higher). The sim was run with 3A /rail simulated load.
Whether this is even useful is dubious, and interpreting it is also something I'm not 100% certain about. I'm not sure how to work out the duty cycle of each diode. However 20A diodes would I think be adequate for at least this configuration and power draw.
Tony.
Whether this is even useful is dubious, and interpreting it is also something I'm not 100% certain about. I'm not sure how to work out the duty cycle of each diode. However 20A diodes would I think be adequate for at least this configuration and power draw.
Tony.
Attachments
Per the Data sheet, if you manage to keep the junction temperature of the device
less then 175 Deg C, you should have no problems. Diodes and rectifiers have
junction temperature ratings which must be adhered to. Often this requirement is
ignored and the Max current rating is stated in isolation until "Blammo" is achieved.
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Actually, if you let LTspice do the RMS and Average calculation, by CTRL-left click on the waveform in specific (tip, do not start to record data until the circuit has stabilised, ie the caps are fully charged, and run a integer number of AC cycles) you see that the average and RMS current is less than 20A. But the RMS current is still about twice the DC load current.
This indicates that a 6-10A diode would suffice. But due to the low PF, fex a transformer would be limitied to about 60-70% of its VA rating
A 300VA transformer would then be limitied at 200-220W power .
Transformers are limited by the I^2*R losses in the windings.
/Rickard
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