An easy tool to build using any case you can find, to allow testing and fast side by side comparison of LEDs to help choose the best colour, intensity and spread.
I built the first of these a very long time ago when the very first affordable gallium nitride LEDs were appearing on eBay. The first ones were clearly factory seconds, so there was a lot of variation in quality. But the availability and lower cost allowed a much larger amount to be used in technical props.
The unit has two sockets on the front, which are just standard two pole 0.1" (2.54mm) pitch sockets. You can use any type with a socket size small enough to accept an LED lead.
When an LED is put in it will either be at full brightness (about 20mA) or a very low intensity at around 5-10uA. The low current can be used to indicate a bad LED as they should normally glow even at such a low current. If they don't glow it may indicate a potentially faulty LED even if it lights up at full current. (Leakage resistance through a faulty layer.)
When two LEDs are put into the sockets you can toggle between them while looking at the projected beam against a wall or other surface. That lets you quickly compare intensity, shape of beam and colour variation. There can be a very wide intensity difference between similar LEDs.
The search keyword for the connectors is KF2510
In hindsight I could have added a barrier between the back of the sockets in case LED leads are pushed in too far and contact internal connections. This 3D printed version is a prototype. You don't need to use a 3D printed case.
If you do want to 3D print one, the openscad scripts are down below.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
https://www.patreon.com/bigclive (extra streams and channel interaction)
Or alternatively:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
Openscad script for main body of prototype tester:-
//LED tester and comparer body
hole=5; //size of switch hole
difference(){
union(){
//main block
translate([0,0,0])
cube([103,36,22]);
}
//battery compartment
translate([8,2,2])
cube([57,32,21]);
//switch compartment
translate([67,2,2])
cube([26,32,21]);
//switch hole
translate([80,18,-1])
cylinder(h=4,d=hole,$fn=50);
//battery cable slot
translate([64,5,7])
cube([4,3,21]);
//1st connector body
translate([90,9,9])
cube([20,5,15]);
//1st connector fin trough
translate([94,13.5,9])
cube([8,2,15]);
//2nd connector body
translate([90,22,9])
cube([20,5,15]);
//2nd connector fin trough
translate([94,26.5,9])
cube([8,2,15]);
//plastic/time saver
translate([2,8,2])
cube([9,20,21]);
//self-tapper holes size 4
translate([4,4,5])
cylinder(h=20,d=2.5,$fn=50);
translate([4,32,5])
cylinder(h=20,d=2.5,$fn=50);
translate([99,4,5])
cylinder(h=20,d=2.5,$fn=50);
translate([99,32,5])
cylinder(h=20,d=2.5,$fn=50);
}
Openscad script for lid:-
//LED tester and comparer lid
difference(){
union(){
//main block
translate([0,0,0])
cube([103,36,2]);
//1st connector retainer
translate([95,9,0])
cube([8,5,9]);
//2nd connector retainer
translate([95,22,0])
cube([8,5,9]);
}
//self-tapper holes
translate([4,4,-1])
cylinder(h=20,d=3,$fn=50);
translate([4,32,-1])
cylinder(h=20,d=3,$fn=50);
translate([99,4,-1])
cylinder(h=20,d=3,$fn=50);
translate([99,32,-1])
cylinder(h=20,d=3,$fn=50);
}
I built the first of these a very long time ago when the very first affordable gallium nitride LEDs were appearing on eBay. The first ones were clearly factory seconds, so there was a lot of variation in quality. But the availability and lower cost allowed a much larger amount to be used in technical props.
The unit has two sockets on the front, which are just standard two pole 0.1" (2.54mm) pitch sockets. You can use any type with a socket size small enough to accept an LED lead.
When an LED is put in it will either be at full brightness (about 20mA) or a very low intensity at around 5-10uA. The low current can be used to indicate a bad LED as they should normally glow even at such a low current. If they don't glow it may indicate a potentially faulty LED even if it lights up at full current. (Leakage resistance through a faulty layer.)
When two LEDs are put into the sockets you can toggle between them while looking at the projected beam against a wall or other surface. That lets you quickly compare intensity, shape of beam and colour variation. There can be a very wide intensity difference between similar LEDs.
The search keyword for the connectors is KF2510
In hindsight I could have added a barrier between the back of the sockets in case LED leads are pushed in too far and contact internal connections. This 3D printed version is a prototype. You don't need to use a 3D printed case.
If you do want to 3D print one, the openscad scripts are down below.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
https://www.patreon.com/bigclive (extra streams and channel interaction)
Or alternatively:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
Openscad script for main body of prototype tester:-
//LED tester and comparer body
hole=5; //size of switch hole
difference(){
union(){
//main block
translate([0,0,0])
cube([103,36,22]);
}
//battery compartment
translate([8,2,2])
cube([57,32,21]);
//switch compartment
translate([67,2,2])
cube([26,32,21]);
//switch hole
translate([80,18,-1])
cylinder(h=4,d=hole,$fn=50);
//battery cable slot
translate([64,5,7])
cube([4,3,21]);
//1st connector body
translate([90,9,9])
cube([20,5,15]);
//1st connector fin trough
translate([94,13.5,9])
cube([8,2,15]);
//2nd connector body
translate([90,22,9])
cube([20,5,15]);
//2nd connector fin trough
translate([94,26.5,9])
cube([8,2,15]);
//plastic/time saver
translate([2,8,2])
cube([9,20,21]);
//self-tapper holes size 4
translate([4,4,5])
cylinder(h=20,d=2.5,$fn=50);
translate([4,32,5])
cylinder(h=20,d=2.5,$fn=50);
translate([99,4,5])
cylinder(h=20,d=2.5,$fn=50);
translate([99,32,5])
cylinder(h=20,d=2.5,$fn=50);
}
Openscad script for lid:-
//LED tester and comparer lid
difference(){
union(){
//main block
translate([0,0,0])
cube([103,36,2]);
//1st connector retainer
translate([95,9,0])
cube([8,5,9]);
//2nd connector retainer
translate([95,22,0])
cube([8,5,9]);
}
//self-tapper holes
translate([4,4,-1])
cylinder(h=20,d=3,$fn=50);
translate([4,32,-1])
cylinder(h=20,d=3,$fn=50);
translate([99,4,-1])
cylinder(h=20,d=3,$fn=50);
translate([99,32,-1])
cylinder(h=20,d=3,$fn=50);
}
I thought I need to make an LED tester. Let's check if Clive has made one. You have! The case is printing as I type.
An easy place to find those connectors is attached to an LED or two! In a no-longer-used computer case, that is. I have a fair collection of these with LEDs in different colors and shapes.
I'm tempted to drive these with an astable multivibrator. Get it going fast enough (a few hundred Hz should do it) and both LEDs will appear to be lit at the same time, making comparison easy. Switch in some more capacitors to slow it down a lot if you want.
I have redeemed myself a bit…😅 Just finished a crude prototype and YAY it works!
I thought for sure the switch I used was fried because it's a plastic rocker switch (stim heaven) and I held the iron on a bit longer than necessary 😫 but it works!
If i pretty it up I may show it off sometime.
I think your circuit might be improved by using a constant current source in place of the resistors. A simple transistor 20mA constant current supply might be used. (20mA being a standard test current for LEDs )
An extra feature might be to add couple of sockets to monitor the voltage across the LED under test. The luxury version could be fitted with one of those nice little voltage display modules. I picked up a few at a radio rally for a couple of pounds each.
This is over kill for an LED tester, but knowing the Vf for a standard test current would be useful.
Black twists matter!!!!!!😀😀
Vise Grip, Sawsall, channel lock… All brand names… So is “Fleshlight”… but that’s another video…
I built one similar to this, but I guilded the lily a bit… It has a pot on the front and a current regulator that adjusts the current from 0-30ma, and then the 3-way switch will go from one LED, to the other LED, and then the 3rd position will put them both in parallel. And it has an internal 1S Lipo with on-board charge regulator circuit.
I went a little crazy with it… I like the simplicity of the one in this video. 👌
Sometimes the simpler, the better.
I really like your case design. 👍
When selecting an LED for a factory production run , get NUMEROUS single samples from various manufacturers …. solder the WHOLE LOT in series , supply from a 10 to 20 mA source ( maybe ? 40 volts , or … MORE than the total forward Volts ? ) …. the really DIM ones show up immediately , and only the bright one(s) , cost permitting , can be selected … ( tried – n – tested ) …… DAVE™ ………….
I would of thought you would of done a lm317 constant current tester with something like 5mA and 15mA currents. As it is now, your lower Vf leds are getting quite a bit more current. EG, a red led Vf~1.8v = 22mA, where a weird blue leds are up to 4.3v = 14mA, so red is getting ~50% more current. Also, I hate 9v batteries ($4 each is stupid), a couple recycled Li-Ion cells would of been my choice, but thats me. 🙂
Is there a risk of damaging the led if it's inserted the wrong way around? I'm worried I might have done just that testing an IR led with 9V batt and series 220ohm.
if your project involves putting leds into an enclosure you could add a diffuser that will moderate the light in the same way that an overcast day does where you wont see a drop in light until well after sunset.
Need polarity test just incase ya cutting up xmas lights and cud use magnetic contacts for normal LEDs
Minimalist case is probably what I would have done too. I think the only difference I might have made was having the battery compartment be a separate cover… maybe gotten a little fancy with a lip for one end and single screw for the other.
I'm both color blind and not an electrician, but if its clive, i watch, always interesting content 🙂