Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Is a Diode a Diode?

2374 views
6 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,016 posts
Is a Diode a Diode?
Posted by richhotrain on Monday, October 28, 2019 5:37 PM

I need to add a diode to each of my signals to allow current to only flow in one direction. In the past, I have bought diodes at Radio Shack, 1N4001 through 1N4004, depending upon which were currently in stock. The package simply referred to them as "diodes".  Now, however, some packages refer to them as "silicone diodes". Other packages refer to them as "rectifier diodes". Is this all one and the same or are silicone diodes different than rectifier diodes?

Rich

Alton Junction

  • Member since
    July 2007
  • From: Yorkton, Sk, Cnd
  • 441 posts
Posted by wvg_ca on Monday, October 28, 2019 6:03 PM

rectifier diodes -should- be the same as silicone diodes ....

unless they say 'tunnel' or 'zener' anyways

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, October 28, 2019 6:26 PM

Diodes have a voltage and current rating.  A normal Google search using the diode number will bring up a data sheet.
 
I normally go with a 1N4001 for 1 amp at up to 100 volts.  About 30¢ State side, 9¢ China.
 
For LED operation I use 1N914, 300ma at up to 50 volts.  About 10¢ State side 2¢ China.
 
If you need a higher voltage or current rating, inter the current needed then browse for the needed voltage.
 
 
Rather than use 4 diodes to make a 1 amp bridge rectifier I buy the DB-107 four pin DIP chip.  About 50¢ US, 20¢ China.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    October 2005
  • 1,033 posts
Posted by betamax on Monday, October 28, 2019 6:41 PM

Most generic diodes are made from silicon.

"Rectifier" it just means that its typical application is for rectifiers, but all generic diodes are rectifier diodes.

What is important is the PIV and maximum current.  PIV is peak inverse voltage, specifying how much reverse voltage it can handle before failure.  The diodes you bought have a PIV ranging from 50V up, so those diodes are more than adequate for your purposes.

 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, October 28, 2019 6:54 PM

 The 1N914 type are fine for LEDs, since they can handle more than 10x the limit of an LED - the LED will pop long before the current dmaages the diode. They are also fine fooor controlling power to Tortoise switch machines, since those only draw about 18ma. 

 To rectify DCC, for installing a lighting circuit in a passenger car for example, it is recommended to use the 1N5400 series diodes - they can better handle the high speed switching of the power. The 1N4000 series are fine to rectify a 60Hz AC into DC, but DCC is a much higher frequency.

 1N5400 series are rated for 3 amps. The last digit indicates the maximum reverse voltage it can stand. 0 = 50V, 1 = 100V, 2 = 200V, 4 = 400V, etc. 

 1N4000 series are rated for 1 amp, the last digit again indicates the maximum reverse voltage, but it's not the same as the 1N5400. On the 1N4000 series, 1 = 50V, 2 = 100V, 3 = 200V, 4 = 400V.

 Reverse voltage is the voltage across the didoe when the polarity is such that current does not flow through the diode. Most LEDs have a relatively low reverse voltage rating, which is why it is usually recommended to put to of them anti-parallel when used with DCC, which means the highest reverse voltage one LED will see is the forward voltage of the one that happens to be lighting up. Or use a standard diode if you don't need two LEDs.

                                    --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,016 posts
Posted by richhotrain on Tuesday, October 29, 2019 12:50 PM

Thanks, guys. I appreciate the information.

Rich

Alton Junction

  • Member since
    November 2016
  • 196 posts
Posted by khier on Thursday, October 31, 2019 10:56 AM

They are different but the differences are irrelevant to your application.

 

Regards

 

Walid

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!