I’ve been using promotional 3 - AAA flashlights with the 9 LEDs / the ones they give at Harbor freight for free… they give a good amount of light for the size.
But I’m noticing that sometimes they may not be as bright as I’d like. I can unscrew the end cap and take out the plastic holder of the 3 AAA batteries and ‘spin’ the batteries in place - just rotate them a bit like a log in the water, put it back together and the light is brighter.
There’s oxidation on the contact surfaces of the batteries and battery holder. I realize that.
Is there something you guys use / recommend to put on the contacts to keep them clean?
And same idea with the threads of the end cap. Just unscrewing / screwing it back on makes the light brighter typically. the body is aluminum I figure.
have a few of those lights, not sure whether a lot of work would be worth it for them. however I would use alcohol to clean the board/springs and good grease for all threads. my board was full with strange stuff I scraped off.
the “driver” on those isn’t high quality, so there will always be the flaky output I guess.
I’ve heard ‘driver’ mentioned here often. Can someone explain that to me? I’m used to incadencents - bulb, reflector switch, battery.
In an LED, I thought there’s just a PC board that the LEDs are mounted on so they are in series / parallel to get the right voltage to each one?. There’s electronics on it also beyond current limiting resistors, etc?
What kind of ‘good grease’ would you use? I think I’ve heard of conductive grease? are there different grades of that I guess those on the contacts and threads woudl keep the contacts from oxidization building up?
Low voltage and high current is the perfect recipe for lots of losses.
I see plenty of steel springs (high resistance) and other crappy materials in those adapters. AAA cells, if alkalines, have quite high internal resistance. Trying to overcome this may be a waste of time, in my opinion. Clean the contacts with some alcohol, and move on.
LEDs exhibit exponential class voltage/current curves, this means slight variations in the voltage they are fed (Vf) with can drastically affect the system's current flow as long as there's no power source bottleneck.
This means the led's resistance to current flow decreases with increased voltage, and also with temperature!
Led's forward voltage (Vf) care/tuning is the role of the driver (or a cheap current limiting resistor if such a simple approach is enough for our needs).
Acetone on a Qtip, dont get it on your plastic parts (they will melt). Most of the retail electronic cleaner is junk. All the good stuff got banned by the EPA years ago.
The led lights have a driver PC board that contains an integrated chip that either current or voltage controls led board depending on applacation. It also has function to control memory and switching hi med low etc… This is just a quick and dirty description there are Threads dedicted to the many types of drivers and there uses.
thanks. The acetone / alcohol is short lived, right? I was thinking there’d be something you guys put on the threads / contacts to protect them on an ongoing basis?
I don’t think you are having oxidation issue, much more likely it is the result of weak spring and poor contact in these bargain basement lights. All of these lights behave this way. Every pressure point connection in the light is problematic including the switch. When you fidget with it it makes a better connection for a short time. Probably get the same result banging it in various ways on a table.
I switched to brake cleaner and have had the same (good) results. I just looked at a few different brake clnrs and they both use Methanol, Toluene, Acetone and Petro Distillates or Carbon Dioxide, whereas CRC contact clnr is Tetrachloroethylene 127-18-4 & Carbon Dioxide. Test your brake cleaner before use on electrical parts/plastic part , some brake cleaners eat plastic. I use it to clean and degrease damn near everything, cheaper than contact cleaner by the way.
I use the gold contacts from an old circuit board. Just rub it on and some of the gold deposits. Rub it on without cleaning. The chrome on those contacts is .0000006 inch thick. You don’t want to rub off any more than you have to.
I can recommend DeOxit. It’s seems to do a really good job on most of my projects. I’m sure most of your electrical contact cleaners would do a decent job. Easy to find at auto parts stores.
