Mesh kit photo transistor specs

I got a bunch of mesh boards (xenon, argon, and boron) a while back and am finally starting to work with them. It appears there are two variants of the photo transistor in the accessory kits. I believe one is Adafruit’s product 2831 (Shenzhen Haiwang HW5P-1). The other is about 2mm shorter, has a larger diameter plate under the sensor, and appears to have a resistance about 4x higher than the HW5P-1 in the same light conditions (checking three HW5P-1s against two of the other kind).

Can somebody provide a datasheet or product identifier for the second type, and ideally information about resistance/lux curves for both?

Let me ping someone that might be able to help, @ParticleD, or @mstanley are you able to assist?

1 Like

Hey Pabigot

Great questions! I believe this is something that would best be answered by our technical docs writer, @rickkas7 He would be able to help you in getting the product identifier for the second photoresistor.

I’m not sure if we host the datasheets for these on our own docs, this may be something you’ll want to grab from the manufacturer’s website.

In regards to the resistance/lux curves, I’m not sure if this is something that’d be included in the datasheet. If not, perhaps Rick will be able to provide some insight on this for us. :slight_smile:

I believe the phototransistor should be this one, or an imitation of this one: Everlight ALS-PT243-3C/L177

That does appear to match the physical appearance and rise/fall times I’m seeing. It’s a much more informative datasheet than the HW5P-1; it has light curves and a more complete example circuit. Thanks!

1 Like