Replacing the current sense resistor in Portable Chargers/Power Banks for powering low power DIY projects.
Mobile Phone/Tablet charging Power Banks can be used to power so many DIY projects. But if your project is low power and draws very little current, the power bank will auto turn off after a few seconds thinking that it isn't being used to charge gadget (because the current draw is very low). I need to figure out a way to hack one and locate and replace the current sense resistor with one of a higher value. Here is how I did it. This told me that the resistor would be located on the return path (ground path) of the output USB connector. I promptly located the R100 SMD resistor in my iBall portable charger. The fact that this resistor was fatter (higher power dissipation rating) and that it was 0.1 ohms in value confirmed that this had to be the current sense resistor Original 0.1 ohms current sense resistor I measured the voltage across it when nothing was connected. It was zero volts and the portable charger turned off in a few seconds when nothing was being charg...
Do you think glop-top IC packing is less reliable, durable and runs hotter than a typical packaging? This's and old reader i still have:
ReplyDeletehttp://mcbx.netne.net/hacks/cardrdr/neo-mod3.jpg
a very discrete circuit, even if you'd pay well for a well done reader, there are not anymore. I'm always afraid that my micro sd card reader (worse than yours, w/o smd caps), kills my 32gb cards (full of hard-important work). What do you think? . Nice blog.
@Blaze:
ReplyDeleteI think that glob top are a compromise on the quality too and yes that does seem to make them run hotter. I guess the best way is to connect your camera to the computer and not use a card reader at all. Now days even built in card readers found in Laptops are based on glob tops.
Its all about bringing down the cost. But then you end up discarding so much of these cheap electronics that it makes you think, wouldn't it be better to pay more for a high quality product that last longer and creates less pollution... but like you said, no one's making them.