| ??? 08/21/09 11:06 Read: times |
#168434 - a universal mobile cell phone charger for example Responding to: ???'s previous message |
Unfortunately I don’t know anybody who has similar experience. But I guess I could get in touch with some electronics grads from my college.
I think an example would work great so…. Let’s take a universal mobile cell phone charger for example 1. can be plugged into a regular 240v a/c plug 2. can charge Nokia, Samsung, iPhone and Sony handsets 3. can be adjusted to switch off automatically after a preset time 4. not larger than a coffee cup 5. lives for 3000 charging hours, can withstand falls form 2 meters A simpler case of circuit design, but a good exercise for a commercial product Suppose I start with this charger circuit http://www.electronicsforu.com/electronicsforu/lab/ad.asp?url=/efylinux/circuit/feb2003/jan02_mobile.pdf&title=Mobile%20Phone%20Battery%20Charger And this timer circuit http://www.electronicsforu.com/electronicsforu/lab/ad.asp?url=/efylinux/circuit/cirmir3.htm&title=Sleep-Switch%20Cum%20Wake-up%20Timer Assuming I have the core functionality working on a bread or design board, and a sketch of the overall look of the product I would say I have the following tasks up my sleeve 1. Fail safe the circuit for the real world: In Per Westermark’s words “Transistors and some IC that have special pads for cooling” ….. “use EMI filters to block noise”…. “capacitors between Vcc and GND” etc. This is a real dark spot for me I guess, because I don’t have experience in real world products. Could you recommend some reading? 2. Miniaturize the circuit: Use smaller components where ever possible and see how small you can make the circuit. (I assume the relay and the transformer will take the maximum space. Wonder if there was a way to miniaturize them! Or use smaller solid state replacements, if any such thing exists) 3. Fit the circuit in the case: Get a CAD software guy to design the casing and see how and where the components could fit inside the casing. Could there be a general purpose casing for this as well? 4. Produce sample and test: Write down the test spec for the product and see if it passes every test case. Probably similar tests will have to be conducted on the design prototype during its evolution 5. Mass produce and quality check each piece Of course I may have to go back and forth between these sometimes. How would you recommend I proceed? |
