12 volt diode question

[hot rod otis]

i need help finding the right diode for a project i am working on. the diode i am looking for will work on 12 volts dc and need to handle 20 amps. any help would be great!
thanks
-otis

 

[Rolf]

i need help finding the right diode for a project i am working on. the diode i am looking for will work on 12 volts dc and need to handle 20 amps. any help would be great!
thanks
-otis

Welcome Otis! You can help us help you if you indicate in what part of the world you live.
Ebay has plenty, that is the first please I look because of the usually low shipping cost small items:
**broken link removed**

 

[hot rod otis]

thanks rolf! i live in omaha, nebraska. i will check out the link you sent and i will keep checking back here too.
thanks again!
-otis

 

[hot rod otis]

i looked at that and the question i have now is will that work on 12 volts? i noticed it says 35v. and, i'm sure i will catch some guff for this question, why does that diode have 3 terminals on it and not just 2?
thanks again
-otis

 

[blueroomelectronics]

What's the deal with the lack of capitals with new posters? Did they not teach them in Omaha, Nebraska?

 

[hot rod otis]

If I start using caps will you help me with my question?
-Otis

 

[blueroomelectronics]

Sure, the 35V 20A is the maximum rating for the part. It'll work fine with anything below those numbers.

 

[Rolf]

i looked at that and the question i have now is will that work on 12 volts? i noticed it says 35v. and, i'm sure i will catch some guff for this question, why does that diode have 3 terminals on it and not just 2?
thanks again
-otis

You always want some cushion because you newer know when you will have a voltage spike. A few hundred percent don't hurt.
Google for the data sheet, I suspect the three pins are connected in parallel and the heat sink is the other; this is in order so that this fairly small package can handle the current and the associated heat.

PS. You still have not filled in your location!

 

[gerty]

Here's one for a couple of bucks:
https://www.mouser.com/Search/ProductDetail.aspx?qs=7r0W2zb/88y0dG0bciVHOQ==
It's rated at 30a at 40 volts..

 

[blueroomelectronics]

It's amazing the TO-200 case can handle 30A, does it require a large heatsink?

 

[hot rod otis]

thanks, oops, Thanks guys. I did check that out and it looks like like the outside terms are common anodes and the center pin along with the base are common cathodes. This is where my lack of knowledge is getting in my way. I am wanting to put this diode inline on a 12 volt wire, just an in and out. Would i just use one anode and one cathode and get a one way current through this thing?
Thanks
-Otis

 

[blueroomelectronics]

That's it. The arrow in the symbol shows current flow.
**broken link removed**
**broken link removed**

 

[Rolf]

thanks, oops, Thanks guys. I did check that out and it looks like like the outside terms are common anodes and the center pin along with the base are common cathodes. This is where my lack of knowledge is getting in my way. I am wanting to put this diode inline on a 12 volt wire, just an in and out. Would i just use one anode and one cathode and get a one way current through this thing?
Thanks
-Otis

I Goggled "diode theory" and found this:
"The diode is to electrons exactly as a check valve or one-way valve is to water. Electrons can easily pass in one direction but are prevented from traveling through the diode in the reverse direction. This is great for changing Alternating Current (AC) where electrons go back and forth inside the wire, to direct current (DC) where the electrons always go the same direction. The diode merely refuses to let the electrons go backward when the voltage reverses. There are literally thousands of other uses for the common diode (sometimes called rectifiers) other than that though."

 

[hot rod otis]

That is great stuff rolf. That was why the 3 terminal thing was throwing me off. I just need in and out, so why 3 terminals? If I understand this right, I can use the terminal that flows in the direction I need and leave the other open and call that done. Sound good?
Thanks again!
-otis

 

[Rolf]

That is great stuff rolf. That was why the 3 terminal thing was throwing me off. I just need in and out, so why 3 terminals? If I understand this right, I can use the terminal that flows in the direction I need and leave the other open and call that done. Sound good?
Thanks again!
-otis

I was not aware that it was actually two diodes in the TO220 case.
Connect pins #1 & #3 together and connect to the positive side of your circuit and pin #2 and the case to the negative.
This will put the two diodes in parallel.

 

[hot rod otis]

We have 14 of em on the way (thanks Gerty). I will keep ya posted on the project.
Thanks
-Otis

 

[shokjok]

Go to NTE-Electronic Components Supplier-Catalog-Cross Reference-NTE Electronics for suitable part numbers.

 

[RODALCO]

Just get a block rectifier. Many of these are rated at 35 Amps, cost only a couple of bucks.

Only use one diode of it and leave the others not connected.

As long you put it on a heatsink. 20 Amps at 0.7 Volts gives 14 Watts in heat to be dissipated.

 

[hnoor0077]

That was why the 3 terminal thing was throwing me off. I just need in and out, so why 3 terminals?????