Ldr

[vne147]

I can't seem to find an LDR (light dependent resistor) at Mouser. There are plenty of optical sensors, photointerrupters, etc but I can't find a simple old fashioned LDR like one you can buy at RadioShack. Maybe I'm just not using the correct search term.

Preferrable, I would like to buy a leaded hermetically sealed LDR so that I can mount it outside like one of the ones shown here. Can someone please help me find one at Mouser? I'd like to order my parts today. Thanks.

 

[Sceadwian]

Cadmium Sulfide cells are what you're looking for. I only looked on Mouser briefly but couldn't find any, they may not sell them as they contain Cadmium so they can't be sold as ROHS compliant, which means they're harder to find. Many electronics manufactors are bulk dumping anything not ROHS compliant just because of the hassle of it.

Try to find another site.

 

[vne147]

That's a bummer. Thanks for checking and thanks for the info. Maybe I'll switch gears and use a phototransistor instead.

 

[DirtyLude]

futurlec still has them. Be prepared to wait forever for shipping, though.

Photocells

 

[KMoffett]

How about Jameco Eectronics: Jameco Electronics - Electronic Components Distributor

Or Allied Electronics: Search results for "photocell" - Allied Electronics

Or Radio Shack: CdS Photoresistors (5-Pack) - RadioShack.com

Or Digikey: Optical - Photo Detectors - CdS Photoconductive Cells (Ambient Light) | Digi-Key Hit VIEW PAGE at the bottom

 

[vne147]

I actually did search some of those suppliers before posting and I have ordered from Futurlec before but would prefer to get the parts before the sun dies out so no thanks. I was already ordering a bunch of stuff from Mouser yesterday and wanted to piggy back the LDR on my order. I was just suprised I couldn't find any there so I thought I'd ask. I order 90+% of my parts from Mouser because they have awesome customer service and I almost always get my shipments the next day on account of my proximity to their distribution center. I guess I'll have to bite the bullet and go somewhere else. Thanks for the info everyone.

 

[mneary]

I've always had excellent service from Goldmine.... these aren't hermetically sealed, but they are cheap. Giant CDS Cell Assortment-The Electronic Goldmine

 

[KMoffett]

Is this what you had in mind for a hermetically sealed photocell? I haven't seen any like that on the market for years. Though I have a few. You would still need to weatherproof the leads. From a quick look at the ceramic base ones from Digikey, all have a plastic coating, with epoxy coating on the leads.

Ken

 

[vne147]

Ken,

That is what I was thinking of. What I want to do is sense light, obviously, that I will feed it into a schmitt trigger/comparator arrangement. I don't know if you've been following **broken link removed** other thread I posted on a temperature comparator circuit but I plan to create a light controlled output using the same method as the temp controlled one. The sensor will be mounted outside so it will need to be weather proofed. I thought that these hermetically sealed LDRs would be perfect for that purpose but I'm open to suggestions if you think something else would be more suitable, cheaper, and/or readily available. Thanks.

 

[AllVol]

futurlec still has them. Be prepared to wait forever for shipping, though.

Photocells

My last order from Futurlec took a total of nine days, and that included the Christmas holidays.

Postman brought the package right to the door... a first for me.

 

[KMoffett]

This is what I'd do for a daylight sensor...if that's what you plan. Cheap and pretty easy. The Plexiglas window is to keep the critters out. The slanted end is to keep the opening clear in rainy and snowy conditions. The photocell and cable are mounted in the end cap. Pressing the cap onto the pipe should be enough to keep it waterproof, but removable. I would also paint the edges of the window to make them opaque This is so light, perpendicular to the tube, doesn't reflect off the window's interior surfaces and into the tube.

Ken

 

[Sceadwian]

AllVol, with Futurelec it depends entirley on what they have in stock when you order. It can be nine days or two months, and there's very little way to predict which it'll be.

 

[AllVol]

AllVol, with Futurelec it depends entirley on what they have in stock when you order. It can be nine days or two months, and there's very little way to predict which it'll be.

That's why I never order anything that isn't in stock. On the oder page, it tells you the stock status. I'm sure some items may change between the time I press the button and the little girl pulls the order, but its not likely. I have really had great success using Futurlec, far more than the complainers would have you believe.

But we're moving off topic.

Good to hear from you Scead

 

[vne147]

This is what I'd do for a daylight sensor...if that's what you plan. Cheap and pretty easy. The Plexiglas window is to keep the critters out. The slanted end is to keep the opening clear in rainy and snowy conditions. The photocell and cable are mounted in the end cap. Pressing the cap onto the pipe should be enough to keep it waterproof, but removable. I would also paint the edges of the window to make them opaque This is so light, perpendicular to the tube, doesn't reflect off the window's interior surfaces and into the tube.

Ken

Thanks for the idea Ken, it looks very doable.

That's why I never order anything that isn't in stock. On the oder page, it tells you the stock status. I'm sure some items may change between the time I press the button and the little girl pulls the order, but its not likely. I have really had great success using Futurlec, far more than the complainers would have you believe.

But we're moving off topic.

Good to hear from you Scead

I have only ordered from Futurlec once and it took about 2 weeks to arrive. Not their fault I imagine seeing how they are on the other side of the world from me. I think I got spoiled ordering from Mouser so many times and getting my order the next day every time with just normal UPS ground. If I ever move I'm going to have to go through an adjustment period.