The There Are No Stupid Questions Thread

I have both the Astrolux ft03 versions. (sst40 & xhp50.2) I’m looking to dedome one of them. Which would be the best to dedome?

Keep the sst 40 dome on the ft03 I cannot speak for the 50.2

The XHP50.2 will be an easier dedome job since it’s a flip chip (no bond wires in top), on the SST-40 you’ll have to be cautions of the 2 bond wires plus the ESD protection diode.

Also, if the sst-40 in your FT03 is anything other than cool white it’ll be impossible to replace if you mess it up.

Wouldn’t dedoming the sst-40 gain more throw than the xhp50.2?

Well yes, but like I tried to explain its a notoriously hard LED to dedome and the supply of non CW SST-40s is literally non existent. If you mess it up on your first try you can not get another.

The dome may also serve as a chemical seal to protect the phosphor from eventual contamination by volatiles coming from the soldering and heat transfer goop.

If you remove the domes you can buy a paint-on liquid sealer and apply that. I used to have a link for that stuff but can’t find it now.

There’s a lot written about failure modes for LEDs, problems that will start to appear over time (only after 10,000 hours, of course, trust the sellers on that).

https://www.tandfonline.com/doi/full/10.1080/09506608.2019.1565716

That makes perfect sense. What about a partial dedome? Not going too low as to harm the bond wires, yet still leaving a protective layer to protect the led?

The word “dedome” implies removing the whole thing. With certain leds you can just slice off the top leaving a thin layer. This has almost the same effect. Candela increases a lot. Some leds are harder to slice than others and the results can vary. With the 50.2 folks recommend a “slice and dice”. You slice off the top and then slice off the sides. This is supposed to help remove some of the yellow corona and or spill, but when I tried the spill light stayed yellow.

It’s always best to have a spare led in case you don’t like the results or accidentally damage it.

Thank you for the info!

That’s good to know. I guess that’s why the Nichia 219C has been popular for use in triple and quad emitter designs?

Okay, here’s my No Stupid Question:

Is this a 7135 * 5 driver?

The missus must prepare the salaries of around 30 employees on a monthly basis (many still handed out as some staff don’t have / want bank accounts) and in addition sometimes have to check other papers of value for authenticity. That’s why she wanted a portable UV flashlight. Something better than the non-portable old and dim unit she now uses. The choice fell on a Convoy S2 Gray 7135 * 5 Driver 365nm Purple UV Flashlight. A seller was easily found on the internet, and the lamp was ordered.

Good price, a series of clear photos of the product and the following specifications were mentioned:

Features (shown in the main photo):

- Gray S2 LG UV 365nm

- LEUVA33W70RL00 LG UV 365nm LED

- 7135 * 5 1750 mA single mode

- ZWB2 filter, and a bit more down the page:

- High quality aluminum alloy.

- LG UV365nm LED 5W lamp beads are used.

- The built-in drive is 7135x5 single file.

  • Life waterproof design.

Out of curiosity, and after playing a little while with the light (yes, we also got ourselves a pair or 3M safety glasses) I opened it and saw that the driver board looked different from the pictures of the seller. I know there is an (old/different?) version with the specs 7135 * 3 but I can’t find a good image of the 7135 * 3, or the 7135 * 5, let alone of the differences.

I know that the current stabilizers (I think that’s the right name but correct me if it isn’t) can/will be on both sides of the board, but because I didn’t take the light further apart I only see the two stanilisers on the spring side. As shown on the second photo both our 2 ‘black boxes’ are printed / engraved? with the text 7135 35P. I can find all different 35 codes, but not 35P. The seller’s photo (photo 1) does not show any visible markings (might be the lighting).

There is another small difference I noticed. On the light she has the name convoy is printed, whereas the seller’s photo shows the text convoy*2* (photo 3).

So my question is, can someone tell me if this is the 7135 * 5 1750 mAh version, or can it be that this is an older 7135 * 3 1050 mAh version? I’m just curious and if it’s not what she ordered I might leave a negative review on the seller’s webpage, to warn others. The missus doesn’t care too much, she’s running around and showing everyone the ‘miracles’ of this little flashlight (and looking silly with those glasses on but I don’t dare telling her afraid she will no longer wear them). I’m sure that by now it has some minor scratches or dents, so it stays, gets used, and abused.

Thank you all! :slight_smile:

The seller’s photo:

The light that came:

Inside the head:

The 7135 is a current regulator. It allows 0.350 amps to flow (some do 0.380, but are not as common). Those drivers typically have room for 8 of these chips. It’s possible the other side has 4 chips making it a 6 chip driver, not 5. We don’t know for sure, though.

Another way to test is to measure the current draw through the battery. A 5x7135 driver should draw 1.75A. A 6x7135 driver should draw 2.1A.

Here are both sides of the same driver with 8 chips attached.


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Who doesn’t have direct deposit these days? My employer actually requires it. From my understanding, it’s expensive for an employer to actually cut a check.

You sound like the tax man looking for people getting paid in cash.

Haha not at all. I’m just saying, there are actually companies that require direct deposit.

I was one of the last holdouts at my place, but this was a few years ago.

I don’t like DD because you’re also giving the usual depositor the ability and implicit permission to also withdraw (without prior consent) in case there’s any “error”.

And I miss seeing Blonde Teller every week or so when I’d go cash the check on my way to lunch.

I agree, yet at the same time I’d rather deal with that than wait for my check to arrive by mail or ha e to drive to the bank to go cash it.

And for some reason 80% of the women who work at the local banks near me look like models. I mean they are incredibly gorgeous. maked me wonder why they are working at a bank lol

Usually, places will have their payroll account at the nearest bank, or at least walking distance in the same neighborhood, so I never had any problem either going during lunch or whenever. You wouldn’t even need an account there to cash the check that’s drawn from that bank.

(’Though nowadays, you’d need to supply a thumbprint, retina scan, stool sample, etc., to be able to cash a check.)

Personally, I’d rather get cash in an envelope…

Thanks Jason! I managed to get the pill(?) out by using circlip pliers but I have no idea how to seperate the driver board from the rest, so it went back in. (and the light still works!)

A neighbour had a DMM, watched the instructions on YouTube and measured the current draw a few times. A mixed bag really, as the numbers kept fluctuating quite a lot (because of moving a bit?), sometimes stopping at a number, pausing, then slowly creeping up in increasements of +1 until it stopped at about +15 from where it initially paused. Here the results:

1st. time: between 940 and 1060 mAh
2nd. time: between 945 and 1131 mAh
3rd. time: between 973 and 1119 mAh
4th. time: between 977 and 1128 mAh

So I’m really no wiser, because I have no idea how accurate that DMM (UNI-T UT33A+) was. 1060mAh seems about right if I look at the specs of a 7135*3 (1050 mAh), 1100+mAh might be a bit enthousiastic reading of the meter. Used battery was a fully charged Shockli IMR 18650 3.7V 3600 mAh.

Maybe somebody with a similar Convoy S2 Grey 7135*5 Driver 365nm Purple UV can chime in, open his/hers and have a look and tell me what he/she sees. As said before, I’m just curious, learning and trying to understand. :slight_smile:

This is rural Thailand where labourers earn a meagre 300 Thai baht a day, the equivalent of just under 10 US dollars. It’s handed out in cash as many of these workers are neighbours from the village and/or have no means of transport, and if they already have a bicycle or a moped, the bank (and ATM) is several kilometers away.

So yes, at the end of the week 300 Thb x days worked (usually 6) goes in a small envelope and is mostly already spent before they even receive it.

I know, old days for many or us but here still standard practice.