hi all,
Just a simple question, I need to replace some old silicong rectifier diode for DC 450 V power supply. is 600 volts diode good enought? I have MR 756, MR 856, and BY 299. Which one has lower switching noise by the way...!
Tks and rgds
William Lee
Just a simple question, I need to replace some old silicong rectifier diode for DC 450 V power supply. is 600 volts diode good enought? I have MR 756, MR 856, and BY 299. Which one has lower switching noise by the way...!
Tks and rgds
William Lee
hi Geek,
I hope to use faster rectifier... perhaps if I put 2 MR in serial??
What is PIV any way?
Tks and best rgds
William Lee
I hope to use faster rectifier... perhaps if I put 2 MR in serial??
What is PIV any way?
Tks and best rgds
William Lee
I thinke the UF4007 (Vishay) will do the job. Fast and enought voltage rating when using in a bridge rectifier
Ahhh, ok, let me look for UF 4007. Some one did suggest FR 107, dont know how good is that one?
best rgds
William Lee🙂
best rgds
William Lee🙂
Peak Inverse Voltage. If you have 450VDC on the positive peak and -450V on the negative peak, you need a 900V rated diode minimum. I'd go with two 1N4007s in series (for 2000PIV), just in case.
FR107 cross-references to RP110 which is rated 1000PIV and 500nS recovery time, fast enough for maybe 20kHz switcher applications I would say.
For 50/60Hz, high speed diodes are not necessary, if the application is RFI-sensitive, some simple snubbers (usually a .01uF ceramic disk across each diode) will keep it down.
Tim
FR107 cross-references to RP110 which is rated 1000PIV and 500nS recovery time, fast enough for maybe 20kHz switcher applications I would say.
For 50/60Hz, high speed diodes are not necessary, if the application is RFI-sensitive, some simple snubbers (usually a .01uF ceramic disk across each diode) will keep it down.
Tim
Tks Tim!
The AC is 340 volts x 2, with a full wave rectification for an 445 Volts output. So in this case the worst case scenerio will be when the B= is 445 volts, and the AC has a begetive 340 volts, ie reverse voltage of 785 Volts....! Pls spike and noised etc..., ok, so I will need to put 2 diode in serial.
I have 5000 PF 600 volts Silver Mica, may be I will use them one for each diode and see how.
Tks again and best rgds
William Lee😱
The AC is 340 volts x 2, with a full wave rectification for an 445 Volts output. So in this case the worst case scenerio will be when the B= is 445 volts, and the AC has a begetive 340 volts, ie reverse voltage of 785 Volts....! Pls spike and noised etc..., ok, so I will need to put 2 diode in serial.
I have 5000 PF 600 volts Silver Mica, may be I will use them one for each diode and see how.
Tks again and best rgds
William Lee😱
Power Diodes
William,
"Normal" rectifier diodes produce switching noise as they turn on after being reverse biased on one half cycle. The suggested (above) capacitors across each diode act to supress this noise and keep it out of your audio signal chain and also help stop radiation of EMI (Electro Magnetic Radiation).
Rather than try to supress this noise its far better to NOT produce it in the first place. i.e. treat the disease and not the symptom.
For this you will want to use "Soft Recovery" diodes.
William,
"Normal" rectifier diodes produce switching noise as they turn on after being reverse biased on one half cycle. The suggested (above) capacitors across each diode act to supress this noise and keep it out of your audio signal chain and also help stop radiation of EMI (Electro Magnetic Radiation).
Rather than try to supress this noise its far better to NOT produce it in the first place. i.e. treat the disease and not the symptom.
For this you will want to use "Soft Recovery" diodes.
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