USB Charger Stand (Making My Own) ?
Cellulars, Kindle, Nook, Yadda. Too many gizmos to count, it seems like. And the ebooks much prefer gentle charge rates (current limiters). Then there is Mexican electricity. In a fit of optimism, I purchased a Meanwell 12-amp power supply ($8.00). 5.0 volts + - 10% adjustment.
Yet another project.
If and only if I can get my hands on the necessary goodies to complete the project.
I want six outlets, but the USB outlets will have permanent 16" long USB cords and they will be designed to be changeable when their tips wear out. Where to buy shorter really great quality charge cords is a question, here. I like braided cords but they are usually 5' in length.
Four of the charging cords will be direct connect while two will have current limiting to 500ma for the ereaders. NOOK is especially mad-dog about insisting on gentle charging currents. It's OK - I have all night to recharge the devices.
Now some more questions...
Obviously 3.7 volt lithium batteries cannot tolerate 5.0 volts. So a device must have an onboard circuit to manage the disparity. A charge controller. What I do not know is if it is "best" to limit current with stuff other than the ereaders. If the answer is "yes" then all 6 outlets will get current limiters.
Do the batteries "suffer" with continuous charging? A laptop's circuit stops charging altogether. Laptop charging circuits cost more than the entire cost of a USB charged gizmo. They can stay plugged in. Putting individual charge time limiters on the new charger will be child's play. And look, it's ridiculous to think precise charging limits are mandatory. I can install 6-hour limiters. Some of the USB gizmos may stay connected for days and days and -that- is what I am concerned about.
Ho ho ho, you say?
Have a friend connect a Scope Meter to the output of YOUR USB charger. Check the RIPPLE developed by your USB charger. Then read up on lithium batteries and their vulnerability to being exposed to a charging current that has ripple. Surprise! It's pure cyanide for the battery. OF course the degree of ripple has everything to do with how good or bad the charging current is for the lithium battery.
With the Meanwell I can build an AC power inlet filter to make its life easier, then add capacitors to keep output ripple to under one millivolt. If you feel like arguing the ripple/battery life issue please do it with the battery manufacturer not me.
Why is this necessary?
It is necessary when one lives so far from the United States that buying (for example) a replacement NOOK means incurring a hundred fifty dollar DHL shipping charge once transfer from the seller's shipper to DHL is made (a hassle and a half). Then, arranging a 300-mile round trip to get to the DHL office. Wanna wait two weeks for a three hundred eighty dollar NOOK? I don't. And NO the battery is not field replaceable, period. I wish they were.
If I can manage to learn what I do not know about small device lithium battery onboard chargers, and secure great quality charging cords, I will build a bedroom shelf device charger that will last. And yes, the Meanwell is built to go the distance 24/7 for many years.
Thanks in advance for tips, and help. And yes, I am close to the border at present and yes the Nook and Kindle are sparkling brand new. After surgeries, I move 2,550 miles further south.
Yet another project.
If and only if I can get my hands on the necessary goodies to complete the project.
I want six outlets, but the USB outlets will have permanent 16" long USB cords and they will be designed to be changeable when their tips wear out. Where to buy shorter really great quality charge cords is a question, here. I like braided cords but they are usually 5' in length.
Four of the charging cords will be direct connect while two will have current limiting to 500ma for the ereaders. NOOK is especially mad-dog about insisting on gentle charging currents. It's OK - I have all night to recharge the devices.
Now some more questions...
Obviously 3.7 volt lithium batteries cannot tolerate 5.0 volts. So a device must have an onboard circuit to manage the disparity. A charge controller. What I do not know is if it is "best" to limit current with stuff other than the ereaders. If the answer is "yes" then all 6 outlets will get current limiters.
Do the batteries "suffer" with continuous charging? A laptop's circuit stops charging altogether. Laptop charging circuits cost more than the entire cost of a USB charged gizmo. They can stay plugged in. Putting individual charge time limiters on the new charger will be child's play. And look, it's ridiculous to think precise charging limits are mandatory. I can install 6-hour limiters. Some of the USB gizmos may stay connected for days and days and -that- is what I am concerned about.
Ho ho ho, you say?
Have a friend connect a Scope Meter to the output of YOUR USB charger. Check the RIPPLE developed by your USB charger. Then read up on lithium batteries and their vulnerability to being exposed to a charging current that has ripple. Surprise! It's pure cyanide for the battery. OF course the degree of ripple has everything to do with how good or bad the charging current is for the lithium battery.
With the Meanwell I can build an AC power inlet filter to make its life easier, then add capacitors to keep output ripple to under one millivolt. If you feel like arguing the ripple/battery life issue please do it with the battery manufacturer not me.
Why is this necessary?
It is necessary when one lives so far from the United States that buying (for example) a replacement NOOK means incurring a hundred fifty dollar DHL shipping charge once transfer from the seller's shipper to DHL is made (a hassle and a half). Then, arranging a 300-mile round trip to get to the DHL office. Wanna wait two weeks for a three hundred eighty dollar NOOK? I don't. And NO the battery is not field replaceable, period. I wish they were.
If I can manage to learn what I do not know about small device lithium battery onboard chargers, and secure great quality charging cords, I will build a bedroom shelf device charger that will last. And yes, the Meanwell is built to go the distance 24/7 for many years.
Thanks in advance for tips, and help. And yes, I am close to the border at present and yes the Nook and Kindle are sparkling brand new. After surgeries, I move 2,550 miles further south.
