[SOLVED] Digital combination locks

Thread Starter

vhiev

Joined Nov 5, 2023
2

Jerry-Hat-Trick

Joined Aug 31, 2022
494
Instead of connecting the green LED 470R resistor to ground, connect it to the base of an NPN transistor with the emitter connected to ground. The green LED should still turn on but less brightly. Connect the solenoid between power and the transistor collector. Check that the transistor can handle the current needed by the solenoid

This uses the transistor to switch the higher current you need from the small current into its base
 

Thread Starter

vhiev

Joined Nov 5, 2023
2
Instead of connecting the green LED 470R resistor to ground, connect it to the base of an NPN transistor with the emitter connected to ground. The green LED should still turn on but less brightly. Connect the solenoid between power and the transistor collector. Check that the transistor can handle the current needed by the solenoid

This uses the transistor to switch the higher current you need from the small current into its base
thank you for your answer.
the solenoid is now working after i added the npn transistor into the circuit.

thank you so much!
 
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