madbeanpedals::forum

Projects => General Questions => Topic started by: RobA on October 14, 2014, 02:03:45 AM

Title: Harbinger LDR specs
Post by: RobA on October 14, 2014, 02:03:45 AM
I'm getting the parts in line to build a Harbinger and I've got to place an order for some other parts at Allied, so I figured that I'd look at getting the LDR's there. But, they don't have an exact match for the Smallbear part. I looked at the part that is spec'd (but no loner available) in the Neo-Vibe article. That part had a 50k-200k light resistance at 10 Lux and a dark resistance of 20M with a wavelength of 550nm for the peak response. I can find LDR's at Allied for around seventy cents that are close to those specs. The NSL-5542 for example. So, the general is, do I need to look for anything else in the LDR or is that going to be good enough?

A related question is, is the hermetically sealed bit important?
Title: Re: Harbinger LDR specs
Post by: Cortexturizer on October 14, 2014, 09:24:06 AM
Quote from: RobA on October 14, 2014, 02:03:45 AM
A related question is, is the hermetically sealed bit important?

This interests me as well.
Title: Re: Harbinger LDR specs
Post by: alanp on October 14, 2014, 09:47:44 AM
If the enclosure has heaps of holes in it to let light in, or you regularly douse it in incense, holy oils, and promethium during Mechanicus rites, then I'd say so.

Rob, enough vertical space to socket and see?
Title: Re: Harbinger LDR specs
Post by: RobA on October 14, 2014, 12:49:26 PM
Quote from: alanp on October 14, 2014, 09:47:44 AM
If the enclosure has heaps of holes in it to let light in, or you regularly douse it in incense, holy oils, and promethium during Mechanicus rites, then I'd say so.

Rob, enough vertical space to socket and see?

I think that the lamp may answer both of those points. Since it's there and not so easily replaced, I'll be trying to maintain a distance between the pedal and incense and bodily fluids -- so maybe no hermetics needed.

The lamps also pretty short, so I'm not sure I can put the LDR's on stilts. I don't really want to socket the lamp. Maybe if there's enough reflected light running around in there it would be OK.

Maybe I'll just order a variety of them and experiment on breadboard.