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sign up here - https://c.org/ShP6jH8JvX

reposting because at the time of OC post, there were not many members on this sub.

just because few weak people couldn't screw the light all the way , they made a downgrade to the product for everyone else.

Now there is no easy way to mechanically lockout the flashlight with this ,you either have to physically remove the battery or use the paper insert they provide with the packaging.

It's a really good light otherwise in almost every aspect. I specially really like the UI (anduril), I hope more mainstream flashlights brands use that.

Review and analysis about crompton night buddy it is BIS certified and does not seem to live up to the sticker

It is a nightlight with an integrated USB A charging port.

Pros:

• Rectification: Utilizes a synchronous rectifier (S7302SL) for output rectification instead of a normal silicon diode. Synchronous rectifier unlike a diode has almost negligible voltage drop keeping the heat to minimum.
• Surge protection: Surprisingly this cheap items has an MOV surge protector that was missing there even in a branded and much more expensive adapter like the amazon basics More info about MOV protection [click here, if you want to check]
• EMI/EMC Filtering: has a proper class Y1 capacitor between the transformer primary and secondary for common mode electromagnetic interference return path. A lot of cheap adapters skip on this and use normal ceramic capacitors which are potentially way dangerous and are not designed to fail open circuit. Class Y1 caps are designed to fail open circuit.

 

Cons:

• Build Quality: Pretty average plastic build, the internal build is too low quality. Looks like a locally manufactured PCB. PCB is only single sided.
• ⚠️ Transformer: I disassembled the transformer and it has to be the worst part of this. It does not have a triple insulated secondary as it should, even worse it appears to be relying on only the thin lacquer that’s on the wire for separation which is not designed to use such. ⚠️
• Power factor: The Power factor is very bad just 0.56, basically the higher it is the better one PF being the best, the better your money is being valued for the electricity bill. If not basically-  It is the ration of actual power being used to do work by the circuit to the total power being supplied to the circuit, here it is less than one, so definitely the total power being supplied compare to what’s being used is way higher here or the total power supplied i.e. ~ 1.8 times more than what’s being actually used.
• Efficiency: at around 10w load I measured 15w being drawn , just 67% efficiency.
• Output ripple: Using the FNIRSI USB tester I check the ripple under around 1.8A load and it is ~500mV Pk-Pk which is totally unacceptable. Though the tester is not as accurate as a dedicated oscilloscope it does give a good idea.
• Wattage & Voltage: It does not supply the claimed current i.e. 5V@2A , It shutoffs above 1.8A and gets even worse when the charger starts heating up with just being able to supply not more than 1.5A. The voltage is also 0.4v higher than 5V under no load. The acceptable USB voltage tolerance at 5v is +/- 5% i.e 4.75V to 5.25V this is above that.

Additional information/Miscellaneous

You can find two versions of this in market

MOV: Rather than a MOV it is a ZOV a zinc-based component that basically works the same. Markings are zov 07d561k. Clamping voltage is 560B +/- 10%. Energy rating is 30joules.

Newer/some units-

Main IC: The main IC is a S7133S https://www.aliexpress.com/item/1005010193911395.html

Synchronous rectifier: It is from the same manufacturer as the main IC  S7302SL https://item.szlcsc.com/5702681.html supports upto 10w and has quite low on resistance at only 22m Ohms.  

Older unit-

Main IC: The main IC is a SMC2010, there is not much info about it on the internet apart form this manufacturer’s/Whitelabler’s page which only mentions the recommended wattage i.e 10W

Synchronous rectifier: Is from the same manufacturer/whitelabler, it is marked as SMC8012

if there are any technical mistakes in my analysis feel free to point them out in the comments.

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Design and controls

The body appears to be made up of some kind of resin plastic which feels really solid, the bezel is made of metal (aluminum).

The body is glow in dark.

The back has a magnet and a necklace attachment. The quick release necklace works well and is made of sold aluminum at the base.

The weight is around 11grams.

The light has four modes:

• Front
• Side
• Beacon
• and indications

The UI itself is very easy to understand, long press to switch brightness/modes on one of the side or main lights and two short presses to switch to side or main

unboxing and output - https://www.youtube.com/shorts/t9EXpsMSW2w

Front light output

The beam really good. It transitions from spot to flood really smoothly. There are no artifacts in the beam.

Wuben claims it can deliver 150lumens in high mode from the front light. According to my testing it started with 183lumens then dropped to 153lumens at 30s and then to around 125lumens at 1min and pretty much stayed constant there.

150lumen might seem low, but the beam is designed in such a way that these are utilized very properly and I think are more than enough for a keychain light

Other modes do not experience any noticeable stepdown even after 2 or 3 min and perform as follows:

Mode	claims	Lumen measured	Lux *5/3 factor
Medium	50	58	35
Low	5	6	4

 

Measured on a homemade integration setup, results may vary or change in future as improvements are made to this

For the current setup, 5/3 is conversion factor between the measured lux and estimated lumens. This factor is based on my current calibration method and may change as the setup is improved

Distance calculations for the front light

Mode	Candela (lux at 1m)	Distance
Low	14	7.5
Medium	100	20m

 

The above where pretty much constant, but the high mode drops by time as follows--

starting with 270cd that is 32m range then drops to 210cd i.e 28m range and then again drops to 160cd or 25m range. Wuben claims upto 29m range.  

Throw calculations for flashlights are normally based on peak beam intensity and the ANSI FL1 convention

The front light is on a very cooler side at 6500k. I believe this is used as cooler LEDs generally have higher luminous efficacy (lumen output/watt pulled) and can produce more output for the same power compared with warmer.

The side light is 4800k which is on the warmer side (these measurements were taken using an android app, users and flashlight community members have had good accuracy results with this)

Side light

The side light lumens were hard to measure as my current integration setup was giving measurements that were all over the place.

The side light is 4800k which is on the warmer side

It has four modes

• High
• Low
• Becon
• Indications

Becon is basically where it pulses and this can be used for indication in the woods/forest etc.  

Indication has two modes short pulses of red or blue light.

The white flood light is really useful if you are working in some tight spaces are there is some place for a magnet to attach, it fills the area well.  

The final thing that remains to test would be the CRI (Color Rendering Index) this basically tells us the quality of the light color for example a leaf with 100% CRI could look same as it would in sunlight i.e as close to natural, lower CRI will off course look quite different.

This requires a special device, which unfortunately I wasn’t able to find for sale in India.

Battery and regulation

The flashlight has 120mAh.

I measured the runtime using ceiling bounce app and these where the results

Front light 

Mode	Claims	Measured
High	30m	30 m
Medium	1h	1h 16m
Low	7h	9h 23m

Side light

Mode	Claims	Measured
High	30m	30m
Low	3h	3h 25m
Beacon	-	-

As you can see from the graph - The output is not regulated to a constant brightness. It gradually drops as the battery voltage drops, mainly due to space constraints in the flashlight, adding additional circuitry that is inductors and switching ICs etc. will need more space and this is probably done to use the battery better without much switching losses and honestly, I don’t mind that much on such a small flashlight.

Charging 

The flashlight uses a liner voltage regulator to charge it’s 120mAh (0.444Wh) battery, it took a energy of 0.667Wh to charge this battery, so it is 67% efficient approx. 33% energy is lost in the charging circuit and battery charging process with the majority probably being lost as heat by the linear voltage regulator.

Reparability and teardown

I did a brief teardown and the light even though is IP66 rated is surprisingly very easy to open. The front metal bezel is easy to pop off and is not held by any sort of glue, quite impressive how Wuben was able to achieve this with just rubber gaskets.

The battery is also potentially replaceable.

I will soon share a detailed teardown and circuit analysis.

Cons-

The biggest con I think is the price that is $20, For less at around $12 brands like Fenix is providing full metal body flashlights (Fenix E01 V2) with easily removable battery. Not a apples-to-apples comparison as E01 V2 is much larger & non rechargeable, has no magnetic mounting and lacks multiple light sources. However, it does show how much more conventional flashlight you can get for less money.

For me personally if I was looking for a keychain flashlight I don’t think those additional features and tiny form factor are worth paying $20 for each. I think the price would be easier to justify if the body was made from aluminum, although I understand that making the bodu aluminum in this size and shape would be considerably more difficult.

Suggestions for improvements

Price - Wuben could maybe reduce the price of this to $8-$10

Perhaps some cost could be reduced by replacing the metal head with a strong plastic or fiber reinforced material, if that it doesn't significantly affect the waterproof rating or durability

Another possible way to reduce the cost could be to offer them in multi packs. For example, something like 5 lights in different colors for around $50 so at around $10 per light, I think the E2 would become a much easier product to recommend, especially since buyers can keep them in different places or share them with friends and family.

Design

A separate charging dock could be provided removing the internal USB C port entirely with pogo pins for attachment to the dock

This could potentially improve three things- the water and dust resistance, more space for the battery, Improved charging efficiency.

Attachments

The necklace attachment requires pressing both sides to attach or remove it, maybe pressing one side can make it easier to remove and attach, probably wuben tried it, but it did not work well so they ditched it for two sides.

Overall, I rate this flashlight a 7.5/10 at the price it is currently

origin - https://www.reddit.com/r/batteries/comments/1wenlwo/anyone_ever_encounter_this_brand_before/

he spoke about evolution of piracy from simple torrents to decentralized, community driven ecosystems like FMHY.

These sites act as curated directories rather than hosts, to bypass takedowns and also how the sites themselves do not host anything it's just a fancy UI with name and takedown will bring in new one with same servers where the content is actually hosted asap.

He also pointed out that, if you can pay for it try to pay for it instead of pirating to support the creators which I also agree with.

link to the video- https://www.youtube.com/watch?v=u7yml8hI_Gg

FMHY link - https://fmhy.net/

original post - https://www.reddit.com/r/AskElectronics/comments/1w9h4xy/life_tone_transistor_radio_model_2601/

Even before this there were automatic options in many CAD software that would auto route traces only, but did not have a option to auto place components.

The benefit I see here specially for professionals and some intermediates (not for beginners), is that this can go thorough datasheets of multiple components at once understand what is what well and maybe place them out in the best optimized way possible. It can take things like EM interference, stray inductance, stray capacitance, and other layout considerations into consideration while deciding component placement and routing.

I personally would not totally trust it as it can still make mistakes would recommend manually verifying everything before final , which is why I don't think it is much suitable for beginners.

I think this can be actually a really useful tool and save time of the pros.

That said, I am honestly kinda scared about the economy and jobs. what are your opinions on this ?

source- https://openai.com/index/gpt-6-astra/

this video - https://www.youtube.com/watch?v=X1lGnB2Vs3E

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thought this post would be suitable here.

Price ~ ₹150/battery

Test

Capacity

• 300mAh claimed 284mAh tested.
• Test parameter - 400mA CC (constant current) load discharge test , 2.8v cutoff.
• Verdict - Close capacity as claimed , will probably provide full claimed if discharge current is low

Internal resistance (IR)

• 142mΩ
• Test parameter- FNIRSI HRM-10 IR tester, Impedance measurement at 1k hertz sine wave
• verdict- Ok for small current draw applications , Unsuitable for drone,High current draw applications etc.

Battery overview -

Chemistry

Li-ion , NMC (nickel manganese cobalt) - more info - https://en.wikipedia.org/wiki/Lithium_nickel_manganese_cobalt_oxides

Size

602030 i.e 6mm x 20mm x 30mm

Additional Info & final verdict

It comes with a BMS attached to the battery itself which is common for these type of batteries. The BMS has Low voltage cutoff (approx 2.5v), It also offers short circuit and over voltage cutoff protection.

From the internal resistance (IR) one can easily calculate that in theory the battery can deliver somewhere around 21A-29A depending on the state of charge, Though this will be limited by the drain to source current rating (I^(DS))of the discharge cutoff MOSFET and main IC internal set. It is pretty generic and does not come with any documentation or datasheet so can't be exactly sure what the max discharge current is possible i.e what exactly is the C rating.

Overall if someone is looking for such small battery they can buy if they want to. The price seems okishly reasonable not the best.

buy link- https://www.amazon.in/dp/B0CYQ6H8FW (non affiliate)

TI sells a light-sensing IC (OPT3001). Since it needs to detect light, the package is clear. I think this is very cool. A couple pictures have a quarter for scale.

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Like slowed and capcut type edit