I usually ask a friend in the US to have things shipped by him, especially when the seller refuses to ship directly or wants to use some shipping service with ridiculous shipping costs. USPS First Class Mail International when possible and USPS Priority Mail International when not… Checking the actual weight of the package at the USPS also gives a correct prize. I sometimes have to ask for the weight and check it myself then send the actual link to the seller for some people to understand… So I guess these extremely tough conditions may deter Americans from shipping overseas…
I have noticed however that Virtual Boy stuff is even harder to get, a lot of it is shipping only within the US.
Shipping via a friend also makes it possible to collect a batch of things and ship it together. Perhaps that’s the kind of service jojobean should offer instead…
I also wonder… it’s more to write when you need to enter the address manually…
EDIT: Didn’t see the news until now. Some people needs change all the time, usually girls…
But, as it’s not a commercial site – or is it – shouldn’t it have an .org-address?
Well, if you do one little piece at the time it would eventually be done. There are finished routines for reading files from an SD card for various PIC and AVR processors…
Yup, not that I have “a good, current-controlled bench supply”, who does? 😉
It’s likely one of those is even better than the standard charger. But nowadays there is usually a microprocessor that checks the voltage regularly and stops the charging when done “delta V” is the new “in-word” for chargers when you read tech magazines.
When I did a job for an electronics company they talked about another company’s UPS (I think it was). They checked the charging of the battery at intervals and recharged the battery by sending a pretty large short voltage pulse that fully recharged the battery – neat method…
I’ve charged a pair of NiMH C-batteries for my bicycle lamp by connecting them directly to a 3V powersupply a couple of times… That seemed to work. 😀
The resistor is there because that circuit is also charging the battery, limiting the current of the charging. When using the battery if the power supply fails or is disconnected the current flows mostly through the diode.
If you don’t have a rechargeable battery you should not have the resistor there. If you do have a rechargeable battery you may need to adjust that resistor so you get a proper charging current (on NiCd and NiMH it usually says how much on the battery).
The batteries will stop charging when the voltage level is high enough – usually you need to use a few volts higher voltage than the battery uses to be able to fully charge it. So a 12V source can’t fully charge a 12V battery. There’s a threshold you need to get over…
The first diode prevents any current flowing out of the circuit from the battery (to a not connected powersupply for example) the second diode prevents current from flowing into the battery – when using the powersupply.
That’s how I understand it. 😉
Make sure the diodes can handle the current you need, I’m guessing 1A is enough for a Virtual Boy application but don’t be afraid to use components that can handle more.
One negative thing about just using a fixed resistor and a power source to charge a battery is that the current changes while charging. If you measure and set it to a certain value at start it will slowly fall as the voltages on the charging side and what is being charged gets closer to each other – but it works, rudimentary. Not recommended for lithium-batteries though – it could be an explosive experience – I haven’t been stupid enough to try it myself though.
If you make your own power adapter for the controller you could build this circuit into it and then have the battery attached to it. So controller, adapter-plate (with circuit and connector for power supply) and then battery attached on the homemade plate…
It probably will unless you seal it with something, but perhaps not at the same rate in normal conditions. It’s like when you get a small rock punching a hole in the paint of your car, if you don’t do anything about it the rust will start eating away below the paint layer…
DogP wrote:
Yeah, but can the copper corrode and turn green inside the cable from sitting on a shelf? Here’s pics from a brand new Dubai display (notice all the green traces, and the green pitting on the wide traces). Compare them to the brownish gold of a “normal” display: http://www.projectvb.com/tech/displayfix/dispinstalled.jpg .
DogP
It looks like it can… 😉
Perhaps it’s because of high air moisture?
How do you solve that, replace it with the thin kind of IDE-cable?
