Hi Tyler, No. You would have to dish out lots of money and take several hours just to build a digital clock. A PDA is incredibly cheap for what it is because those multi-national conglomerates have built the whole thing on one chip that costs about $0.25 to stamp out. The rest of the cost is the case and software, oh yea, and something to cover the millions of dollars in development costs. If you want to play around with some basic concepts, thats fun and educational, but you will never build anything as complex as a PDA. :) Regards, James jimpanes@xxxxxxxxx jimpanes@xxxxxxxxxxxx "Everything is easy when you know how." ----- Original Message ----- From: Tyler Littlefield To: programmingblind@xxxxxxxxxxxxx Sent: Sunday, February 22, 2009 4:43 PM Subject: Re: using breadboards I figured I was totally scrued up. It's just something I want to do. I have an idea for a PDA I would like to build that sounds fun, just my personal little PDA. I could totally customize it, and it would be cheaper than anything I could buy more than likely. I also want to just learn how these things work. I've often found them interesting. I have been digging around for some electronics tutorials, but haven't found all that much that doesn't consist of a ton of pictures, etc etc. ----- Original Message ----- From: The Elf To: programmingblind@xxxxxxxxxxxxx Sent: Sunday, February 22, 2009 2:34 PM Subject: Re: using breadboards lol, odd list to send this to, but I used to do modular electronics, so your in luck. firstly, that setup will not do the job, you need to find a basic electronics tutorial and read it, smile, not ragging on you, just the truth. there are basic principles that you haven't grasped yet. for a battery charger, you need the 110 volt (wall) plug, a transformer, you need a full wave rectifier (I'll explain in a minute) and you may want some filter capacitors, though there not really needed for a bat charger. now then, your first mistake is that your setup would have put wall type current, called AC for alternating current, into resisters and batteries which are DC (direct current) devices , that's a large shocking flam buoy recipe. number two, you said resisters to bring the current down, yes resisters will drop current, but not in the way you need it to, this kind and type of current step down is done with a transformer (that's why so many things with removable wall plugs have that large box either at the wall end, or in the middle of the cord, the box is mostly the transformer that reduces the voltage and changes the amperage of the wall current. and without the full or half wave bridge rectifier I mentioned before, your still plugging DC parts into an ac circuit, another flam buoy! the full wave bridge rectifier I have been mentioning is the component that changes the AC current coming out of the transformer into DC current for the batteries to charge off of. here is the correct series of components for a simple power supply: 1. 110 volt power plug, which you attach to a specific set of contacts on a 110 AC to... (output voltage equals the number of batteries going into the battery holder, times 1.5 volts) so if you have a battery clip for 2 batteries, then its 3 volts, if its four then it's six volts) AC transformer (note here, all the transformer does is change the voltage and amperage of the power, not its type, at this point you still have AC current running through the thing). 3. to the output side of the transformer you attach the input leads off the full wave bridge rectifier (this is the device that changes the power from AC, to DC so its the same type of current as your batteries). 4. to the output side of the FWBR you can either: 4-1. insert two filter capacitors to screen out noise the circuitry generates, but this is not needed in a simple charger(*note,! the filter capacitors have to be hooked up the correct way, one end is positive one negative). or, 4-2. attach your battery holder, making sure you get the polarity of the wires correct to the battery holder , or your making a loud bang and a lot of stink and a hazard out of your batteries. another point, this simple setup has no way, like many chargers you buy do now a days, to tell when the batteries are fully charged, and stop trying to charge them, and this will heat up, and eventually give you another ka boom. the circuitry for a regulator is not to hard, but I can't pull it out of my head like I can a simple power supply. that is the basics of a power supply and it will work as a charger. and it will not cost much, but why reinvent the wheel, unless your going to try for some work in the electronics field? which I would not advise, some of the stuff is extremely complex, and some of it quite delicate, and none of it is marked in a method that can be read with our current tech abilities. laters, inthane ----- Original Message ----- From: Tyler Littlefield To: programmingblind@xxxxxxxxxxxxx Sent: Sunday, February 22, 2009 12:06 PM Subject: using breadboards Hello, I'm looking to start using breadboards to create some small things. I'd like to start off with something small, possibly a battery charger or something similar. I found a small tutorial on instructables, but not totally sure how to get going. It explained how things work somewhat, but not accurately enough for me. It mainly used pictures to explain, which didn't do me a whole lot of good. Any ideas on how I can set this up? I understand the polarity--hooking one negative end to the positive etc so that the circuit forms a loop, I'm just not sure how to do what I want. So, here's my idea. If I figure out the layout, I can set up a power cable going from the outlet to the breadboard. Then I can place in jumpers to bridge the gap. I can take the 120 volts down to 9 with some resisters (?) and hook a battery pack to the other end that will charge the batteries. I'm thinking I'm way off, but... ideas would be great. If I could, I'd like to set it up so it'd charge like 4 at once, then I could cut down the 120 to 36. Possibly put in a heat sink to keep it from getting really hot.