What is the difference between 3mm and 5mm led

Luxeon Lumileds and Cree are very bright and have a wide angle. But their 3V drops to 2V then a blue, modern green or white LED will not work since they need about 3. It depends. I have found most 3mm LEDs have max 10 to 20mA current rating and 5mm typically have 25 to 30mA rating. The voltage is a function of the band-gap chemistry and doping and therefore independent of diameter. Other people may have dealt with different 3 and 5mm LEDs so they will have different answers. There are about 3 and 5mm LEDs at my distributor.

I'll let you look them up. Now that I've written all of that, are you willing to tell us why you want to know? If the LEDs are fairly directional narrow beam then the diameter of the housing won't make much difference to the light output, so 3mm and 5mm should look much the same at a distance.

If the bargain LEDs happened to be out-of-spec manufacturing rejects then there could be brightness variations within the batch.

Similar threads R. Replies 14 Views 1K. Jan 21, Mike odom. Replies 3 Views 25K. Feb 7, danrogers. Replies 3 Views Jul 10, chemelec. I need more than a light detector. Replies 11 Views 1K. Nov 4, jsolos. LED Light. Why can't we use a 5mm LED as the flasher in this circuit? What's the difference between a 3 mm and 5 mm led? How do you identify one? Nothing in that says it needs to be 3mm.

Any size LED will work - the warning is that it needs to be a flasher type LED, since it relies on the current drawn by the flashing LED to drive the transistor switching the other one. It says that a normal LED will not work. The paragraph does state that the LED in the picture is 3mm, so I can understand the confusion. However, a flashing LED has a small circuit built in to make it self-flashing.

In summary, if you can find a 5mm flashing LED, you can go ahead and use it! Just make sure it is a flashing LED though!

A quick Google of flashing LEDs will give you numerous results with different sizes. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. SteveScott Member. Only difference is the size. DGWVI said:. Click to expand Chuck D.

Bones Well-known member. Color, on the other hand, makes a big difference because they all have a different forward voltage. Bones said:. Diffused colored and clear will not have any differences between the same colored light. Edit: Go with the reds, as I doubt the UVs will actually do anything- they have a huge forward voltage.

The actual diode radiates a single color. I have used white LEDs in solid-state amp distortion circuits.