I can recall using a ULN2003 chip (which contains 7 of these) when building a few projects back in college. The ULN2003 itself is able to source 500ma (600ma peak) worth of current itself. So depending on the needs of the relay this chip would probably suffice. I also have to agree...
Using 2 resistors and an input voltage, we can create an output voltage that is a fraction of the input. Below you can see the formula that you need to use to calculate the resistors that you need in your circuit: Solving the formula above withVin=5V, R1=1000ohmsandVout=3.3V. We get...
Here is a useful tool to test the working of the Remote handsets used for operating TV, VCD player, and other remote-operated gadgets. These devices use Infrared rays pulsating at 38 kHz and the sensor used is the TSOP 1738 specially designed to sense the 38 kHz IR rays. The circuit giv...