I have a Chinese LED Flashlight myself. Mine is a bit more advanced, but it uses the same dodgy plug. In my grandparents' house (which was made in the 60s) we still have some flat bed plugs, so I could plug the flashlight there easily. Once while I was taking it out somehow I touched the live connector. Luckily I was not grounded, but it zapped the f**k out of me. I reworked it and turned it into a DC flashlight that uses an external AC/DC converter.
Also, there are the shallow European sockets used almost exclusively in Asia. They have no earth connections and it looks like a circle with two holes. I think this is designed to go into those.
Someone asked me to repair one of those. Looking inside, I found out that the connection to the battery was broken and all the LEDs were burned. Because there is no filtering, nor any parallel resistance, without connection to the battery the LEDs are exposed to much higher voltage than their ratings and therefore will burn very fast.
I had a lot of Chinese products with rechargable battery and they usually die after first few chargings. To plug it in you need to use some kind of plug extender which is sold separately
Once I tried to measure the open circuit voltage of such a charging circuit from a rechargeable light and I got around 150 VDC but after connecting the battery, the voltage drops to 18 V
I hate these chargers, but if this torch had an intelligent charger module this would be one of the most reliable torches, why? even if one of the LEDs burn out the rest of them still works.
I would say it looks LETHAL! Especially with the nocturnal habits of the LEDs, which quite rightly we should avoid at all costs. However when you told us to avoid "it" I did have a childish giggle to myself :D 😁😂 Díky!
It could be modified to an 18650 battery, but I'd have to replace all the LEDs, they are all bad. It uses standard low power 5mm LEDs, so it is not very powerful. There's no heatsink, sou you can't easily use more powerful LEDs. This flashlight is rubbish. There are much smaller flashlights that are much brighter.
thats 4v lead acid battery.. these type of torches and lamps are popular here in india because they are very cheap mainly because of that battery which is really really cheap here. it will charge with 240v and they are dangerous i have got myself shocked many times when trying to modify it
At 60 Hz, add 20% to the current. Here in the US, it would use 45 mA@120 V, or 90 mA@240 V. For Europe, they use 50 Hz, which means 75 mA@240 V, 37 mA@120 V. These values basically neglect the 5 volt drop of the battery, assuming it is indeed a 2-cell lead acid battery. In this light, the battery is constantly overcharged, so it relies on its oxygen cycle to dissipate excess energy, once fully charged.(rather poor design)
Your calculations are exactly what I got for 50 Hz mains. I'm from the United States of America, we are at 60 Hz. Thus, the light would draw 90 mA @240 V, and 45 mA@120 V. The reason for individual resistors is because LEDs have varying threshold voltages. That means that the current would not be equally distributed among all elements, causing some to be brighter than others at the very least, and at worst, some LEDs could be overloaded. As an LED gets hotter, its forward voltage drop goes lower, which means the hottest LEDs will draw the most current. That would shorten the life of the LED flashlight(torch) as a whole. I agree with you 100%, I would like to see a 22 Ohm resistor on the input, and a 200 mA fuse on the input, to limit inrush current in case the plug makes contact during the peak of the AC wave form, and the fuse, just in case a diode shorts, or the capacitor shorts. I would like to see a 400 V capacitor used. If it is indeed a lead acid battery, there needs to be a Zener diode, or a series of silicon diodes, to limit the voltage to the battery at about 4.6 to 4.8 volts, to prevent overcharge, if it is indeed a lead acid battery. Diodes are great, because they will change with temperature, like the battery does, and help maintain an appropriate float voltage for the battery at varying temperatures. That would allow the unit to remain plugged in safely, until needed. It wouldn't take much, to make it a very useful and reliable emergency light source, or, just simply handy. I'm really interested to see what kind of battery it actually is. Lead Acid batteries don't like continuous overcharge, especially at a high rate compared to its capacity. That design won't hold up if someone just leaves it plugged in all the time.
Another error: The capacitor is on high value. The 4V battery is approximately 1Ah. And you charge it on 220V. The charge current must be too low (for on 110-220VAC). So, the capacitor may be 470nF - 400V AC type. My god! The text on the box errorly too. That torch produced for studying "how produce an errorly flashlight".
If you notice the 1 microfarad capacitor on the input, At 240 V@50 Hz, it only allows .075 amps(75 milliamps) of current to flow. The Oxygen cycle in the battery shunts this to about 5.2 volts. The current remains pretty close to constant, weather the battery is dead, or fully charged. the problem is, battery overcharge. I'm sure you noticed the bulging in the battery, though that could be the result of a capacitor with too low a voltage rating shorting out, which would indeed have tried to pass all that voltage into the battery. If you have this light, don't leave it plugged in continuously. It's better for the battery if it's plugged in for 24 hours, then, unplugged. If you think about it, plugging it in for a couple of hours every week would ensure its longevity, and, maximum hours of run time per charge. For very little more cost, they could have shunted the battery with a series of diodes, to protect the battery from overcharge, which would allow the light to remain plugged in until needed. A 400 volt 1 microfarad capacitor wouldn't be much more expensive, than the inadequate 250 volt capacitor that was used. I would pay an extra dollar for it, if it had these extra 20 cents worth of components in it.
What do you mean by the wall plug mechanism looking dodgy? It's space shuttle technology right there. Chinese space shuttle... :P Welcome to the warm, sparkling, tingly and exciting coziness that is teardowning of chinese ebay/ali-finds! :D I just love that stuff, I hope you make many more (and survives, lol).
Its only for the non-recessed Thai sockets ( lethal without shielded pins ! ) & Chinese death-travel-adapters & Chinese multi-plug death sockets ^^ Oh ans classical Capacitive-Dropper of death ( see "BigCliveDotCom" & "John Ward" ) instead of an isolated power supply ^^ its good that it does not fit in recessed German & French sockets, this is the only thing that makes it safe ^^ Edit: good video
Dude, it would be nice if you show the light beam coming out of this flashlight. We already know its a junk just by looking at it. And EU socket is not hollow but recessed. Thanks
The battery is garbage. The Charge circuit won't pass enough current to bring the LED's up to full brightness. That's assuming IT even works. I do believe, the LED's themselves might not work either. To pass 20 mA in to each of 18 LEDs would require .36 amps, the charge circuit would at best, provide about 1/5 of that.
It's not hard. The resistance of the capacitor to AC voltage is 1/(3.14*2*F*C) where F is either 50Hz or 60Hz mains frequency and C is capacity in Farads. So 1uF = 0.000001 F here. For example 1 uF capacitor at 50 Hz has the resistance of 3184 Ohm. Next calculate the current which is 220V/3184 Ohm = 69 mA maximum because I have ignored the battery (or other load after the bridge rectifier) voltage. For some better precision we could calculate (220-Ubat-1.2)/3184 where 1.2 stands for two diodes voltage drop because they are connected in series to be a bridge.
Crap light. Theres also no limit to the charging voltage. Probably why the battery bubbles. In my european country we have wall sockets wich are not resseced and plugs without the isolation ... I have never heard it should be any problem safety wise. Thanks for the teardown.
buming Plup Directiy Buibs Forkword Hight LT can save electricity Love the Chinglish : If there would be LTT (LinusTechTips) can save electricity i would laugh hard
You'd think this was the first crap, Chinese product he had ever seen. Not only is the product not up to code, but they lied about the flashlight's specs. The product might also have been made by someone who did not know what he was doing. There was some good detective work done in the video, but instead of the flashlight being weird it is just a ripoff product. TH-cam must be changing some of their algorithms because this is the first time I've seen this channel. I've been seeing many channels like this one just pop up recently in the recommended videos list.
sir i have 30w led chip i run 19.5v laptop adapter here amp rating is 3.3amp led glow but blinking what i do . i install 12v cooling fan also to keep led chip cool.
240 volts AC actually reaches 340 volts peak to peak. Because there is a zero crossing as the polarity reverses, the average effective voltage is the stated 240 volts. If you connect an incandescent lamp to a sine wave with 340 volt peaks, it will shine the same brightness as if it were connected to a 240 volt battery. Therefore, the capacitor has to be rated for that peak voltage. The capacitor actually sees about 334 volts, because you can subtract voltage drop in the bridge rectifier, and the finishing charge voltage of the battery. You can neglect the resistor in parallel with the capacitor, it's such a high value that it only contributes a fraction of a milliamp to the bridge rectifier. If you want to know how much current will go through a given size of capacitor, multiply the value of your capacitor X the voltage across the capacitor. At 50 Hz, like you have in Europe, divide that product by 3,183.0989, and that will tell you the amps going through the capacitor. Here in the US, we use 60 Hz, so we would divide that product by 2652.5824. We will get 20% more current through a given value of capacitance at a given voltage, due to the 20% higher line frequency.
Sir I don't know rated value but I am shore this chip is 30 watt. Firstly I use 12v 2amp adapter its brightness little low after 4 to 5 days my adapter suddenly short circuit And never repairable. Pls tell me about amp or milli amp its working condition bcos I control voltage but how to manage amp or milli amp. Pls clear this picture. Thanks 4 reply.
I WISH ONE COULD BUY flash LIGHTS WITH ON OFF SWITCHES INSTEAD OF THE 3 OR 5 SETTING ic boards that drain my battery i guess i cab buy a old 6volt lantern n stick a car led head light in it with a battery pack n dimmer knob and a toggle switch be a cool build fer this guy to do ..pardon the capital letters i hit caps button wilts pecking words out
![[MV] A leap of faith...ความเชื่อใจครั้งสุดท้าย (From "Petrichor the series")](http://i.ytimg.com/vi/U1piZH2CNXA/mqdefault.jpg)
I have a Chinese LED Flashlight myself. Mine is a bit more advanced, but it uses the same dodgy plug. In my grandparents' house (which was made in the 60s) we still have some flat bed plugs, so I could plug the flashlight there easily. Once while I was taking it out somehow I touched the live connector. Luckily I was not grounded, but it zapped the f**k out of me. I reworked it and turned it into a DC flashlight that uses an external AC/DC converter.
Once the same thing happened to me
7:27
In china, they use the lead wires as fuses! XD
I once took apart one of those. It had sealed lead acid battery in it, but its terminal was potted with *twinkly nail polish.*
When I opened one of these I thought it was glitter glue
That is a scary looking thing.
Also, there are the shallow European sockets used almost exclusively in Asia. They have no earth connections and it looks like a circle with two holes. I think this is designed to go into those.
This was the same in Europe in 1950's
they use them in italy, with ground in the middle
I was hoping you would plug it in to see the battery explode.
Someone asked me to repair one of those. Looking inside, I found out that the connection to the battery was broken and all the LEDs were burned. Because there is no filtering, nor any parallel resistance, without connection to the battery the LEDs are exposed to much higher voltage than their ratings and therefore will burn very fast.
Love that Chinglish manual:-) :-) :-) :-)
I had a lot of Chinese products with rechargable battery and they usually die after first few chargings. To plug it in you need to use some kind of plug extender which is sold separately
Once I tried to measure the open circuit voltage of such a charging circuit from a rechargeable light and I got around 150 VDC but after connecting the battery, the voltage drops to 18 V
I hate these chargers, but if this torch had an intelligent charger module this would be one of the most reliable torches, why? even if one of the LEDs burn out the rest of them still works.
This type of plug used in India. Indian sokets are similar to European soket but the diffrence is European soket is hollow and Indian soket is Flat
I would say it looks LETHAL! Especially with the nocturnal habits of the LEDs, which quite rightly we should avoid at all costs. However when you told us to avoid "it" I did have a childish giggle to myself :D 😁😂 Díky!
China has a weird socket which accepts EU, US and Australian plugs. Not every EU socket is hollow, but these contacts look dangerous.
Looks like it might fit a shaver socket - pin setup looks fragile
Can you please modify it using 18650 battery and charging system for 18650. In addition, can be use also as a power bank. Cool huh?
It could be modified to an 18650 battery, but I'd have to replace all the LEDs, they are all bad. It uses standard low power 5mm LEDs, so it is not very powerful. There's no heatsink, sou you can't easily use more powerful LEDs. This flashlight is rubbish. There are much smaller flashlights that are much brighter.
thats 4v lead acid battery.. these type of torches and lamps are popular here in india because they are very cheap mainly because of that battery which is really really cheap here.
it will charge with 240v and they are dangerous i have got myself shocked many times when trying to modify it
I want to see what inside the battery?
It's an Lead-Acid battery!
Two lead plates immersed in a gel containing sulphuric acid.
very nice review. Only a small correction if you don't mind. In the case of 110v is 60hz and not 50.
At 60 Hz, add 20% to the current. Here in the US, it would use 45 mA@120 V, or 90 mA@240 V. For Europe, they use 50 Hz, which means 75 mA@240 V, 37 mA@120 V. These values basically neglect the 5 volt drop of the battery, assuming it is indeed a 2-cell lead acid battery. In this light, the battery is constantly overcharged, so it relies on its oxygen cycle to dissipate excess energy, once fully charged.(rather poor design)
Your calculations are exactly what I got for 50 Hz mains. I'm from the United States of America, we are at 60 Hz. Thus, the light would draw 90 mA @240 V, and 45 mA@120 V. The reason for individual resistors is because LEDs have varying threshold voltages. That means that the current would not be equally distributed among all elements, causing some to be brighter than others at the very least, and at worst, some LEDs could be overloaded. As an LED gets hotter, its forward voltage drop goes lower, which means the hottest LEDs will draw the most current. That would shorten the life of the LED flashlight(torch) as a whole. I agree with you 100%, I would like to see a 22 Ohm resistor on the input, and a 200 mA fuse on the input, to limit inrush current in case the plug makes contact during the peak of the AC wave form, and the fuse, just in case a diode shorts, or the capacitor shorts. I would like to see a 400 V capacitor used. If it is indeed a lead acid battery, there needs to be a Zener diode, or a series of silicon diodes, to limit the voltage to the battery at about 4.6 to 4.8 volts, to prevent overcharge, if it is indeed a lead acid battery. Diodes are great, because they will change with temperature, like the battery does, and help maintain an appropriate float voltage for the battery at varying temperatures. That would allow the unit to remain plugged in safely, until needed. It wouldn't take much, to make it a very useful and reliable emergency light source, or, just simply handy. I'm really interested to see what kind of battery it actually is. Lead Acid batteries don't like continuous overcharge, especially at a high rate compared to its capacity. That design won't hold up if someone just leaves it plugged in all the time.
Another error: The capacitor is on high value. The 4V battery is approximately 1Ah. And you charge it on 220V. The charge current must be too low (for on 110-220VAC). So, the capacitor may be 470nF - 400V AC type. My god! The text on the box errorly too. That torch produced for studying "how produce an errorly flashlight".
DiodeGoneWild, How this charging circuit could charge this 4 volts Pb battery, as it should be very high output voltage after the bridge rectifier ??
If you notice the 1 microfarad capacitor on the input, At 240 V@50 Hz, it only allows .075 amps(75 milliamps) of current to flow. The Oxygen cycle in the battery shunts this to about 5.2 volts. The current remains pretty close to constant, weather the battery is dead, or fully charged. the problem is, battery overcharge. I'm sure you noticed the bulging in the battery, though that could be the result of a capacitor with too low a voltage rating shorting out, which would indeed have tried to pass all that voltage into the battery. If you have this light, don't leave it plugged in continuously. It's better for the battery if it's plugged in for 24 hours, then, unplugged. If you think about it, plugging it in for a couple of hours every week would ensure its longevity, and, maximum hours of run time per charge. For very little more cost, they could have shunted the battery with a series of diodes, to protect the battery from overcharge, which would allow the light to remain plugged in until needed. A 400 volt 1 microfarad capacitor wouldn't be much more expensive, than the inadequate 250 volt capacitor that was used. I would pay an extra dollar for it, if it had these extra 20 cents worth of components in it.
What do you mean by the wall plug mechanism looking dodgy? It's space shuttle technology right there. Chinese space shuttle... :P
Welcome to the warm, sparkling, tingly and exciting coziness that is teardowning of chinese ebay/ali-finds! :D
I just love that stuff, I hope you make many more (and survives, lol).
Indiskret1 sir China tourch ke led bulb ki kya wattage hoti hai hume kesse pta chlta hai ki kithne wattage ka bulb lga hai
You could use an italian plug for all those that don't fit the eu one
May be the dropper capacitor can rated for both AC and DC Voltage.
The german socket is The best
Its only for the non-recessed Thai sockets ( lethal without shielded pins ! ) & Chinese death-travel-adapters & Chinese multi-plug death sockets ^^
Oh ans classical Capacitive-Dropper of death ( see "BigCliveDotCom" & "John Ward" ) instead of an isolated power supply ^^
its good that it does not fit in recessed German & French sockets, this is the only thing that makes it safe ^^
Edit: good video
It would also fit Italian plugs but without shrouded pins it's absolutely unsafe.
You can get this lower than 3 dollars in china
I think is for 12 to 24vdc connection if capacitor is 250vdc
I too, would use just 1 resistor
This socket is old brazilian socket
Dude, it would be nice if you show the light beam coming out of this flashlight. We already know its a junk just by looking at it. And EU socket is not hollow but recessed. Thanks
All the LEDs are burnt out so that's not possible.
The battery is garbage. The Charge circuit won't pass enough current to bring the LED's up to full brightness. That's assuming IT even works. I do believe, the LED's themselves might not work either. To pass 20 mA in to each of 18 LEDs would require .36 amps, the charge circuit would at best, provide about 1/5 of that.
Have you measured the battery and the capacitor?
saudações do Brasil + like. informações úteis. sucesso.
And what about measurements? And your dodgy adapter to plug it in? Or solder a mains cable? No test???
circuit diagram round hi/lo switch cannot be correct or it would be on ful in both hi and lo positions
I have the same battery in my flashlight and it's 3.4v
What chemistry, what cell count? Do you know?
Some old eu sockets are flat and don't have earth.
Flat earth confirmed!
Chinese wall sockets have 2 pin euro sockets that are not recessed
The charger is really dojjy, the brown capacitor may explode at any moment and make the battery acid leak all over the torch
In some Asian countries, they have sockets that accept European plugs, but are not recessed.
Yes, I am from Bangladesh and we have such sockets without recess.
There might be a short circuit in battery
Sana Usman even better reason to plug it in
75mA*12h=900mAh
Pls plug it in power socket
In China, the fuse is firemen
Chemical batery
where are you located? Czech or US? :) nice day
He's from Czech :)
Can anyone tell me how do I calculate capacitive dropper circuit's output current
No.
It's not hard. The resistance of the capacitor to AC voltage is 1/(3.14*2*F*C) where F is either 50Hz or 60Hz mains frequency and C is capacity in Farads. So 1uF = 0.000001 F here. For example 1 uF capacitor at 50 Hz has the resistance of 3184 Ohm. Next calculate the current which is 220V/3184 Ohm = 69 mA maximum because I have ignored the battery (or other load after the bridge rectifier) voltage. For some better precision we could calculate (220-Ubat-1.2)/3184 where 1.2 stands for two diodes voltage drop because they are connected in series to be a bridge.
Lead acid batteries are dangerous
Led is 4.8 mm
I think these are straw hat LEDs. They give more light probably.
Avoid bumming 🤣
When Chinese make them
Scary lamp ! 😚💥💥💥😉
4 VOLT Battery!!!
Crap light. Theres also no limit to the charging voltage. Probably why the battery bubbles.
In my european country we have wall sockets wich are not resseced and plugs without the isolation ... I have never heard it should be any problem safety wise. Thanks for the teardown.
migsven surfing jm
7c
Looks very flimsy
Old swiss socket works fine. But very dangerous: Breaks easily. Very poor quality!
buming
Plup
Directiy
Buibs
Forkword
Hight
LT can save electricity
Love the Chinglish :
If there would be LTT (LinusTechTips) can save electricity i would laugh hard
13:54 I have the same typo on my cooling fan
"Portable rechargeabie cooling fan" :)
6:04 *notices the buldge* OwO what's this?
What happened to my sense of humor that i find this funny now
@@janno288
Hi, it's me 6 years later. Forgive me for that comment for it's cringe af
@@antonybronco4463 No problem haha i found it funny
👍👍👍👍👍
You'd think this was the first crap, Chinese product he had ever seen. Not only is the product not up to code, but they lied about the flashlight's specs. The product might also have been made by someone who did not know what he was doing. There was some good detective work done in the video, but instead of the flashlight being weird it is just a ripoff product. TH-cam must be changing some of their algorithms because this is the first time I've seen this channel. I've been seeing many channels like this one just pop up recently in the recommended videos list.
Tf are you talking about you wacko
It's designed to plug directly into the wall plug.
sir i have 30w led chip i run 19.5v laptop adapter here amp rating is 3.3amp led glow but blinking what i do . i install 12v cooling fan also to keep led chip cool.
Sunny Chopra what is the rated voltage of the chip?
where 373 Volts ? series RC circuit Drops the Voltage and limits the Inrush current no ? Measure It Please !
240 volts AC actually reaches 340 volts peak to peak. Because there is a zero crossing as the polarity reverses, the average effective voltage is the stated 240 volts. If you connect an incandescent lamp to a sine wave with 340 volt peaks, it will shine the same brightness as if it were connected to a 240 volt battery. Therefore, the capacitor has to be rated for that peak voltage. The capacitor actually sees about 334 volts, because you can subtract voltage drop in the bridge rectifier, and the finishing charge voltage of the battery. You can neglect the resistor in parallel with the capacitor, it's such a high value that it only contributes a fraction of a milliamp to the bridge rectifier.
If you want to know how much current will go through a given size of capacitor, multiply the value of your capacitor X the voltage across the capacitor. At 50 Hz, like you have in Europe, divide that product by 3,183.0989, and that will tell you the amps going through the capacitor. Here in the US, we use 60 Hz, so we would divide that product by 2652.5824. We will get 20% more current through a given value of capacitance at a given voltage, due to the 20% higher line frequency.
Sir I don't know rated value but I am shore this chip is 30 watt. Firstly I use 12v 2amp adapter its brightness little low after 4 to 5 days my adapter suddenly short circuit
And never repairable. Pls tell me about amp or milli amp its working condition bcos I control voltage but how to manage amp or milli amp.
Pls clear this picture.
Thanks 4 reply.
First improve your English please, then talk.
Haaahaha , first of all i ne ver talk 2u, then why r u behaved like broker.
Sunny ch Sorry, didn’t get what you are saying. Also what do you mean like broker?
Sunny ch Also if you want to control amp or milli amp, then get a variable power supply
European
Bapskatha
The flashlight uses a Chinese outlet as it's plug.
49% nn 149%
I WISH ONE COULD BUY flash LIGHTS WITH ON OFF SWITCHES INSTEAD OF THE 3 OR 5 SETTING ic boards that drain my battery i guess i cab buy a old 6volt lantern n stick a car led head light in it with a battery pack n dimmer knob and a toggle switch be a cool build fer this guy to do ..pardon the capital letters i hit caps button wilts pecking words out
You first world people have never seen this type of light, in third world countries this was common in the last decade
Those plugs are not european but asian.