Increase Red Dot Brightness

[AshOnSnow]

I've got a EOTech style red dot sight, but it's always been rather dim (in daylight, you have to use the green setting on full brightness to clearly see it, red light is unusable in anything other than dusk/night). Wondering if I'm able to increase the brightness.

I'm guessing it's built from 2 LEDs, one red and one green, with a circuitboard hosting a stepped potentiometer controlled by the brightness buttons, a switch controlled by the NV button to change colours, and another switch to turn it off and on, controlled by the 2 bright buttons again - pressing either one will turn it on, pressing both simultaneously will turn it off.

Since the LED brightness is controlled, to an extent, by the current flowing through it, would I be able to increase the brightness by increasing the overall voltage supply? It's currently 3V (2x 1.5V AA), perhaps pushing up to 4V would be able to push the current up and increase the brightness without blowing the whole board, providing the brightness isn't controlled by a clipper/limiter module and adjusts relative to the current.

Thoughts?

 

[Prisce]

Unfortunately there is a lot more too this than you think. The components may be rated to only 4V meaning if you put a 4V battery in, your likely to blow it.

The only really way to tell is to take the thing apart. I would imagine it’s actually 2 circuits joined in parralel. 1 circuit for the green, 1 for the red, with perhaps a relay/diode linking in the middle to toggle between the circuits.

Without taking it apart it’s impossible to tell, it could just be shoddy wiring, or to many connections causing resistance or even dirt cheap LEDs that don’t work effectively.

 

[AshOnSnow]

Unfortunately there is a lot more too this than you think. The components may be rated to only 4V meaning if you put a 4V battery in, your likely to blow it.

The only really way to tell is to take the thing apart. I would imagine it’s actually 2 circuits joined in parralel. 1 circuit for the green, 1 for the red, with perhaps a relay/diode linking in the middle to toggle between the circuits.

Without taking it apart it’s impossible to tell, it could just be shoddy wiring, or to many connections causing resistance or even dirt cheap LEDs that don’t work effectively.

PITA. Why would it require 2 circuits, if the green and red LEDs run off the same control (ie, you turn the red down, then switch to green, the green is also down. Turn the green up and switch back to red, the red will have increased also)? Wouldn't it have been simpler and cheaper to produce on one circuit?

I suppose I could always buy a new, better one. ffs

 

[Prisce]

Unfortunately with most things it’s space and cost. 

You also have to think, if you put both bulbs in 1 circuit, there is twice as much to go wrong. Whereas if you have 2 circuits with a relay switching between, only 1 circuit is in use at 1 time, so the components don’t get used as much. 

I will try drawing something later(god help you) that should make more sense. 

I am just guessing at this time, never taken one apart to work on, but working with electronics, I would imagine my way would be what they use, or what I’d hope they’d use.

 

[Adolf Hamster]

unfortunately it's almost certainly all solid state, you might have some luck replacing the individual led with a brighter one but tbh it's almost certainly more hassle than it's worth (for a start if the circuit has some form of current limiting hardware)

if i were trying this i'd pull it apart and find an electrical engineer to beat into modifying the circuit for me.

 

[Rogerborg]

Send it to Big Clive for a teardown?

https://www.youtube.com/user/bigclivedotcom/videos

Half serious suggestion, although his track record on putting things back together again isn't steller.

 

[AshOnSnow]

unfortunately it's almost certainly all solid state, you might have some luck replacing the individual led with a brighter one but tbh it's almost certainly more hassle than it's worth (for a start if the circuit has some form of current limiting hardware)

if i were trying this i'd pull it apart and find an electrical engineer to beat into modifying the circuit for me.

Is there such a thing as a brighter one? If there's no way to increase the current to the led anyway?

 

[skintrade]

This is something that people forget about LEDs and light in general, wavelengths that the human eye interprets.

Comparing brightness the 3 main LED colours used in electronics are Red < Green < Blue (check your home in the dark with tech active but lights out to see what i mean). This also means that a lot of red dot LEDs seem underpowered in daylight.

There is an argument for not using green in daylight depending on environment, green getting lost on green, but in daylight green will be naturally brighter. Upping the brightness of a dot also risks of visibility from the opposing POV depending on the sight.

 

[Guest]

I pulled one apart, it fell to bits immediately.

I don’t think it’s the LED’s, it’s the mirrored glass that’s the issue. It’s not a real holo sight, so you need mirrored glass to reflect the LED, but that also makes the whole view dim.

I’ve had loads, and they’re all shite unless it’s bright daylight. You could try replacing the glass with Perspex (LED won’t reflect as well) OR polish some of the mirroring off the glass. 

IF you can polish off the mirroring everywhere APART from the tiny spot the LED needs (once zeroed) you MIGHT get it to work.

Otherwise, forget it

 

[Adolf Hamster]

This is something that people forget about LEDs and light in general, wavelengths that the human eye interprets.

Comparing brightness the 3 main LED colours used in electronics are Red < Green < Blue (check your home in the dark with tech active but lights out to see what i mean). This also means that a lot of red dot LEDs seem underpowered in daylight.

There is an argument for not using green in daylight depending on environment, green getting lost on green, but in daylight green will be naturally brighter. Upping the brightness of a dot also risks of visibility from the opposing POV depending on the sight.

iirc isn't the main reason red is used is precisely because of this effect, that it doesn't ruin your night vision (that is to say your natural vision, not goggles) at night, the same reason red torches are often used.

 

[skintrade]

Yep red light is often used for illumination as it has low disruption for night vision, but also the length of the light wave is harder to see at distance, reducing the risk of being spotted.