circuit board is widely for switching Electrical load via Microcontroller or
any other means (TTL logic). By this PCB one can able to switch ON/OFF up to 4
than use individual Darlington transistors, you can use an integrated circuit
specially designed for driving high-current loads from TTL-level inputs. The
most common ICs of this type is ULN2003, which has 7 Darlington drivers in a
16-pin DIP package.