Trouble with GPIO

[phentux]

Hi everyone, i have a triuble with the output of the GPIO. I want to use a relay with the output, i supose the A is not enough because the relay turns on with 3V, the V of the output. Now my question is, how can i do for turn on the relay?

I tryed with the Darlington NPN configuration with the 2N2222



But nothing happen. Please, help.

PS: I know about the existance of the relay card:



But i cant use it. Really, thank you.

[FLYFISH TECHNOLOGIES]

Hi,

But i cant use it.

Connect together GND of RasPi and GND of the relays' power supply.


Best wishes, Ivan Zilic.

[phentux]

Hi,

But i cant use it.

Connect together GND of RasPi and GND of the relays' power supply.


Best wishes, Ivan Zilic.

Hello Ivan, well, if i dont do that will never work, but my question is about what kind of transistor should i use for this, and what configuration. Thanks.

[FLYFISH TECHNOLOGIES]

Hi,

my question is about what kind of transistor should i use for this, and what configuration.

What is required current to fire the relay ?


Best wishes, Ivan Zilic.

[Richard-TX]

You dont need a transistor to fire the relay. What is really needed is to fully turn on the opto-isolator. Thos Siansmart relays are not the best designed boards around. If you really want to use a transistor, I would use a 2N7000.

[phentux]

I really dont know, i dont have a multimeter, but with the current of the 5V output of the RPi is enough. So, I can use a transistor to amplify the current, but i dont know how.

[Tarcas]

You really don't need a transistor in the circuit. I have a 4-relay board similar to that and it works on 3.3v to the IN pins.

I must confess I'm not entirely sure what that IC between the Pi and the Relay board is for. Is that a buffer? A transistor array? Sorry... I didn't use anything there.

Connect the 5v to JD-VCC on the board, not VCC.
Connect 3.3v from the Pi to VCC on the board. (This is compared against the 3.3v on the IN pins. If you're using a 5v GPIO, you would jumper 5v between both the VCC and JD-VCC rails.)
Connect your GPIO pins
And of course the ground from Pi to ground on the board.

This setup worked for me.

[phentux]

You really don't need a transistor in the circuit. I have a 4-relay board similar to that and it works on 3.3v to the IN pins.

I must confess I'm not entirely sure what that IC between the Pi and the Relay board is for. Is that a buffer? A transistor array? Sorry... I didn't use anything there.

Connect the 5v to JD-VCC on the board, not VCC.
Connect 3.3v from the Pi to VCC on the board. (This is compared against the 3.3v on the IN pins. If you're using a 5v GPIO, you would jumper 5v between both the VCC and JD-VCC rails.)
Connect your GPIO pins
And of course the ground from Pi to ground on the board.

This setup worked for me.

Thanks Tarcas, but i dont have the relay board, so i cant use it. I need the transistor.

[FLYFISH TECHNOLOGIES]

HI,

I need the transistor.

I like when people take life in a simple way... As said, to answer you about proper transistor, we need to know the current trough the relay. Optionally, post the relay label/type/model.

Without this information I could only write: NPN transistor + 1k ohm base resistor + protection diode like 1N4001.


Best wishes, Ivan Zilic.

[phentux]

HI,

I need the transistor.

I like when people take life in a simple way... As said, to answer you about proper transistor, we need to know the current trough the relay. Optionally, post the relay label/type/model.

Without this information I could only write: NPN transistor + 1k ohm base resistor + protection diode like 1N4001.


Best wishes, Ivan Zilic.

This is it!!! thank you man!!!

[Tarcas]

How to use relays and relay boards with the Pi This video should show you how to wire up your relay, without the extra components being included on the board.