Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Dont have 1n4004 diodes for Dummy load. Any alternatives ?




diachi

Well-known member
Joined
Feb 22, 2008
Messages
9,796
Points
113
As long as you know the voltage drop and current ratings of the diodes you can figure it out. Obviously signal diodes won't be able to handle that sort of current. Most silicon rectifier diodes should be fine though. You can always measure the drop with a DMM.
 

WizardG

Well-known member
LPF Site Supporter
Joined
May 9, 2011
Messages
1,029
Points
113
1N400x will work fine. All the 1N4000 series diodes have about the same forward drop. The difference between 1N4001 and 1N4004 is reverse voltage rating.
 

LaserCo

Active member
Joined
Sep 25, 2007
Messages
435
Points
28
1N400x will work fine. All the 1N4000 series diodes have about the same forward drop. The difference between 1N4001 and 1N4004 is reverse voltage rating.

^^^ yes, and I will add the 1N400x series are all 1 Amp.
 

lasersbee

Well-known member
Joined
Sep 20, 2008
Messages
17,680
Points
113
You may be able to salvage some suitable diodes from some
old circuit boards. The 1N400X series is a silicone rectifier
diode so look at the power input section of some PCBs. They
are also commonly used across relay coils to reduce back EMF.

Jerry
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
The 400x series are indeed pretty much identical apart from maximum reverse voltage. I only keep 4007s in stock for that reason, they are (not interestingly) more expensive than other 1n400x diodes if you buy them by the 100 or so.

The 1n4004 is nothing special, it's rated to 400 volts dc so it's just a very common type of mains rectifier diode. It is normal silicon, high forward voltage, slow response, and can probably be substituted for -anything- you can yank out of a mains rectifing circuit that can handle 1 amp.

Considering how cheap they are i'd just buy them, but if you are in a hurry and have some discarded PC power supply around you can surely take some diodes from that as an instant substitute. Just make sure to pull them from the mains voltage end and not the output, as those diodes are often rated at a lower reverse voltage and could be lower drop, but faster, shottky ones as well.

In the application shown here that does not matter at all, but in general you should take not of this in higher voltage stuff.
 




Top