Hi Tyler, A transformer would be much better to step down the voltage and use lots less power. You will also need some sort of rectifier or full-wave bridge to convert the power on the 9 volt side from AC to DC. If you want to do a battery charger right, there should also be some type of a cut-off that detects when the current drops (indicating that the battery is charged) and turn the circuit off. HTH 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 3:06 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.