Your average Pound shop or Dollar store usually has some very useful low voltage (about 3V) LED arrays that can be used in projects or to fix other lights.
(Note that some of the round lights may apparently run quite hot.)
The COB (Chip On Board) modules usually have an aluminium backed PCB with flip-chip LEDs on it, protected by a layer of phosphor loaded gel. A flip-chip LED is a bare "dice" with metal contacts formed on the back of it as part of the manufacturing process, so it can be soldered directly in place with no need for bond wires.
For project use these COB arrays will need a resistor top limit current.
In the video I also converted one of the lights into a rugged magnetic emergency light that charges from a USB charger. If making your own in this style the batteries MUST be either Nickel Metal Hydride (NiMh) or old fashioned Nickel Cadmium (NiCad) cells. Non rechargeable cells like alkaline or zinc chloride will pressurise and may explode.
You could also use a protected lithium cell. But it would absolutely have to have protection fitted.
The resistor values can be juggled to suit your needs, noting that continuous trickle charging at high currents will reduce the working life of NiMh cells.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
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.
(Note that some of the round lights may apparently run quite hot.)
The COB (Chip On Board) modules usually have an aluminium backed PCB with flip-chip LEDs on it, protected by a layer of phosphor loaded gel. A flip-chip LED is a bare "dice" with metal contacts formed on the back of it as part of the manufacturing process, so it can be soldered directly in place with no need for bond wires.
For project use these COB arrays will need a resistor top limit current.
In the video I also converted one of the lights into a rugged magnetic emergency light that charges from a USB charger. If making your own in this style the batteries MUST be either Nickel Metal Hydride (NiMh) or old fashioned Nickel Cadmium (NiCad) cells. Non rechargeable cells like alkaline or zinc chloride will pressurise and may explode.
You could also use a protected lithium cell. But it would absolutely have to have protection fitted.
The resistor values can be juggled to suit your needs, noting that continuous trickle charging at high currents will reduce the working life of NiMh cells.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
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.
perfect for modification with scavenged dispo vape batteries
Take a new lamp ( as above ) and fit a diode bridge rectifier across the COB + a 10 microfarad electrolytic … then supply the AC side of the bridge via a MAINS RATED 100nF capacitor and 220 Ohm resistor or use a 100nF snubber ( neutral to other AC input of bridge ) connect other side of 100nF to mains live ( ! ) = super efficient " night light " that will last forever ( my version has been continuously connected for 10 years ( or more ! ) hint : X2 100nF motor noise suppressors are ideal !
i found a similar work light on ebay uk using the search terms " led magnetic work light torch lamp builders" it has a dc socket on the back which went straight to the battery holder made modding it very easy
I just bought one of those calipers and it works great. Stupid cheap too.
It Seems Clive has his spies everywhere. Whenever I visit my local el cheapo store ( Otherwise known as The Reject Shop here in Australia ) looking for items to experiment with/on , The items I purchase are debunked on Clive's channel.. Usually only a couple of weeks before but then again, some have been well over a year.. I take great pleasure in debunking some of the more dangerous items I have found . From USB chargers with mains potential across them, Mains Power sockets where the on off switch is in the Neutral wire on both outlets, Power saver plugs which do nothing and lots of cheap chinese rechargeable batteries with unholy capacities printed on them. I even found the LED lamps that Clive has studied and modified plus I rebuilt the solar LED PIR outside lamps with better batteries and a much better solar charging regulator… Clive, Keep up with the videos please, you are legend among Aussie Electronic and electrical enthusiasts..
Take apart the poundland fantastic fan.
Clive, Can you explain why adding 2 x 22Ohm resistors gives you 11 ohms and not 44?
am i wrong or are the batteries in the diagram drawn wrong? shouldn't they be reverse: the short sides on top long sides bottom?
Add some defusing media 'opaque plastic' and those heavy lines should disperse?
I have just bought a few of these- very good they are.
BTW: If you strobed the LEDs – would the batteries last longer? Like 60+hz?
I recently came across a bevy of these at the Dollar General for $1.00 ea. They are bright as the sun. Ima gonna go back and buy all of 'em!
have you checked the battery drain on the calipers when they are off? they seem to eat batteries very quickly.
Bought one of the round ones. Perfectly fine! Good red light on it too. Some cyclists round here could do well to invest in one!
black birds ravage our yellow grains butchering very good wheat: resistor colour code after 35 years still know my resistor bands lmao teacher always said we would always know it cuz memory aid