[SOLVED] Want to know the value of transistor

[jay_3189]

I want to control a 6 solenoid valves(Operates at 24DCV and 0.5A) with the use of 6 relays connected to an Arduino's 6 pins via 6 BJT(NPN) Transistor.

The Arduino output pin is 5V and can source 40mA maximum.

I would like to use a relay to switch the valve on and off.

So, suggest me that which transistor is better to use here and value of resistor that I have to put between arduino and transistor.
and DC voltage for relay to operate.

 

[Venkadesh_M]

make sure your relay takes 0.5A, typically its about 0.1A and at that point you can use a BC107... measure and tell the coil resistance... If your rating is correct then you can use BC 337 with 1kOhm in base....

 

[tpetar]

I want to control a 6 solenoid valves(Operates at 24DCV and 0.5A) with the use of 6 relays connected to an Arduino's 6 pins via 6 BJT(NPN) Transistor.

The Arduino output pin is 5V and can source 40mA maximum.

I would like to use a relay to switch the valve on and off.

So, suggest me that which transistor is better to use here and value of resistor that I have to put between arduino and transistor.
and DC voltage for relay to operate.

Voltage for relay coil should be used according to relay datasheet. If you have 12V relay, then use 12V for relay coil.

2N2222, BC817, BC546,...



Best regards,
Peter