Can someone help confirm if this part is a good match?

[DrGonz78]

I am working on a Yamaha PA head and have come across a part that is obsolete. Well the original part is bad but not sure how to read the datasheet on this one to match it up. Reverse voltage, forward voltage drop and recovery time has me confused as I go to Mouser or somewhere to find the part. I read the best I can between these parts and feel this replacement part might do the job. Can anyone help reaffirm that this part is a good match or suggest a better one? Thanks

Original part is: ultra-fast-recovery rectifier diode RL2Z
RL 2Z.pdf
rl2z.pdf

Replacement part:
EGP20D Fairchild Semiconductor | Mouser

[Enzo]

It's just a fast diode. What is your area of confusion?

Reverse voltage is just how many volts the thing can block in reverse, like a 1N4007 is 1000v, this RL2Z is 200v. It's a 200v diode, with a 2A rating

Ultrafast is a description of type, meaning it can operate at high frequencies without bogging down.

The RL2Z has a recovery time of 50 nanoseconds, and so does your Mouser part, so what is the question there?

Every diode has some amount of voltage drop across its junction. Your RL2Z has a 0.98v max, while the Mouser part has a 0.95v max. COme on, you beefing over 3/100 of a volt?

[DrGonz78]

Good so I was right on finding the part . Yeah I thought about the .3 volt for about a second and thought it is fine. No really my Beefing was just looking at all graphs and charts about the part. This tends to get me thinking a part is very well thought out and I am not. So yeah as you always say this is not rocket science but sometimes these charts boggle me up. I just don't like when I jump ahead and order wrong parts, that's really what my worry was... Thanks again Enzo!

[km6xz]

There is an illusion of accuracy in electronics because we have 6-7 digit meters, see great resolution in calculated values but little has changed from the slide rule era in that any given circuit has few parameters that mean anything past the 3rd significant digit. The only area of electronics that routinely keeps high precision and accuracy is time bases, anything else requires building a prototype to actually measure what the circuit is doing regardless of the reliability of the calculated values and models. So your part and the original, statistically, have the same likelihood of performing the intended task.

[Enzo]

Yeah, that was 0.03v, not 0.3v, by the way.


Stan makes the point. A long while back when digital volt meters were not a given, a lot of guys had to adapt away from an analog meter - with a needle - and struggled. I sold a guy a digital meter I had, and he complained, I can;t get a good reading, all those numbers flashing and changing all the time. I told him to take a piece of tape and cover the last couple digits, he didn;t need them. It didn't matter that the voltage varied from 5.103v to 5.108v. 5.1 was plenty accurate enough.


I have a news reporter who takes a cassette deck into the field for interviews. She gets them from MArantz, who no longer makes them for retail, but will put one together from parts special order for her. She then edits the interviews. As I replaced some little tiny switch contact in the third or fourth of these units, I suggested she just get a modern little digital recorder. Oh no, can't do that. She could rewind so the counter was at 186 and a half or whatever on her taper, but those darn digital machines had all those numbers. Probably should have told her to get out the tape too.

[DrGonz78]

It's a good thing this isn't rocket science because I would have blown up a lot more stuff by now!!

Yeah I meant .03v whoops! lol. It is very easy for me to not see these throw it away numbers and I don't even need tape. All the information passed on here is always a very eye opening experience. I am just very thankful there is a such great community of pro's out there willing to help, thanks! Just keep reminding myself to pay attention to the details but not TOO closely. Each experience is a good lesson here...

[J M Fahey]

t little has changed from the slide rule era

Gasp!!!!!!
I still have a couple and in fact, carry one everywhere.
Love to dazzle the shop salesmen and other customers with it
The cherry on the cake is that it's a *circular* one

[Enzo]

Oh the circular ones. The good thing about those is if you work at it long eneough, the answer will... come around.