Posts

Showing posts from March, 2013

12V 7.2Ah SMF Battery Charger: Smart Approach for Smart devices by Smart People !!

Image
Difficulty Rating: 5/10 Abstract: This project gives an overview of the Sealed Maintenance-Free (SMF) Lead-Acid Rechargeable Battery charger using 3-pin  IC LM-317 as voltage regulator and opamp IC LM-324. In case of a simple battery charger, when the battery is fully charged and is left plugged in for more than a day or two, the battery may get damaged. In order to protect the battery from this major risk, the proposed battery charger is designed in such a way that the charging current falls gradually as the charging progresses. So the battery can be left plugged into this charger indefinitely, and it won't bother it in the slightest. Designing the Circuit:   Click the image to view the enlarged version The LM317 is an adjustable three-terminal positive-voltage regulator capable of supplying more than 1.5A over an output-voltage range of 1.25 V to 37 V. It is exceptionally easy to use and requires only two external resistors, R 2 ’ and R 2 ”  (R 2 ...

L293D: A notion to be cleared

Image
IC L293D, is the Motor Driver IC, which is usually linked to Robotics Applications. Even if you tend to use this guy, few basic questions still arouse in the minds of budding Hobbyists; Like Why 2 supply pins on the IC, How much voltage can be given to the IC, Should I short all the Ground pins of the IC ??????  Here, I'll be explaining the Pin description of L293D and not the specifications or other technical details. You can refer datasheet for that. L293D datasheet click here. To start with, any Microcontroller development Board works with a Max. of 5V, with a few hundreds of mA current. In case of ARDUINO Duemilanov: DC Current per I/O: 40mA DC Current for VCC & GND: 200mA  Is this current sufficient enough to drive a everyday 12V, 200RPM DC motor ? No.  So what ? Use a Motor Driver.  Does it help ? Yes. It converts low current to high, sufficient to drive a motor. Pin Conections (Important: Even pro's tend to m...