ULN***3A Module V1.0 -Arduino Compatible
The ULN***3A is a circuit module used to drive high current loads, it can directly drive a relay and also be used for level conversion. Each ULN***3A has eight load interface and can drive up to eight high-current load. "VEX" and "5V" interface can be used for an external power supply. The **5 chip is used for the ULN***3A cascade and the function of its corresponding interface "**5IN" and "**5OUT" is to connect the Arduino and to implement the cascade between the ULN***3A.
Its maximum voltage is *0 V, maximum output voltage is *0 V.
For example, when you use the SCM or MCU as the output current signal, which is too small to direct drive big load, then you can choose this ULN***3A module.
ULN***3A module's 4 up road and 4 down road is load (such as LED lamp tape) slot, each slot can be connected with one LED lamp tape. So every ULN***3A module can drive 1~8 LED lamp tape.
ULN***3A module's power supply is divided into two parts, one is VEX POWER driven green terminal on the module with the mark "VEX", which is the power of driving ULN***3A, and it requires users to connect the external POWER supply, when the requirement voltage of driving load is bigger than 5 V, you will use this VEX interface. The ULN***3A VEX interface can connect with the highest *0 V voltage.
Note: If the voltage of drive load is greater than 5 V, the jumper position is shown as below:
Another part is the interface that provide ULN***3A chip internal logic level 5 V power supply module interface, which is also the **5IN interface of this module, it is used to connect with the IDC*6 interface of Arduno IDC shield module, then getting 5 V logic level from Arduino derectly through connecting the **5IN interface with IDC*6 interface.
If the voltage of driving load is equal to 5 V, logic level is equal to the voltage of driving load, at this time, we may don't need external power supply, and can directly use logic level of **5IN port to drive the 5 V load.
Note: If the voltage of driving load is equal to 5 V, the jumper position is shown as below, and without external power supply:
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