ESP8266 Community Forum

- Wed Jan 21, 2015 1:15 pm #7882 cant see exactly the traces on the board but you can try to find out which resistor is connected to the optocoupler input pins and try to short the resistor (R1 and R4 I think)

Code: Select allIN 0-------[]----------------->|------------GND
        resistor     led inside optocupler


- Thu Jan 22, 2015 1:57 am #7924 Hey,

Quick reply:

Here is the schematic of the relay board:

Code: Select all                                JDVCC   RELAY
                                  o   o       o
                                  |   |       |
                                  |   |       |
                                  |   |       |
VCC o---[R1]------[OPTO1][OPTO3]--------[D1]-----[Q1-3][Q1-2]-
                                                              |--o GND
IN1 o---[IN1]-----[OPTO2][OPTO4]--------[R2]-----[Q1-1][Q1-2]-


So when the jumper is between JDVCC and VCC both the relay coil and the opt led are powered from the same source but you can power them separately.

Hope this helps.

- Thu Jan 22, 2015 8:34 pm #7991

Hey,

Code: Select all
VCC o---[R1]------[OPTO1]                                                   
IN1 o---[IN1]-----[OPTO2]


Are you shure about this - on this schematic its look like as you turn on the relays with LOW signal.
Check only the two pins of the optocoupler closer to the input - Imagine its an LED - when the LED is on, then the relay should be on.

- Fri Jan 23, 2015 1:49 am #8000

Hey,

Code: Select all
VCC o---[R1]------[OPTO1]                                                   
IN1 o---[IN1]-----[OPTO2]


Are you shure about this - on this schematic its look like as you turn on the relays with LOW signal.
Check only the two pins of the optocoupler closer to the input - Imagine its an LED - when the LED is on, then the relay should be on.

Just rechecked... You are correct...
Don't have to imagine as there is really an LED in there we just don't see it.

When you connect VCC to power and the jumper is in position you have to connect IN1 to a LOW pin for the relay to work (and of course GND to ground).

Another way to make this work is to separate the whole thing into two circuits. The first one is the one you drew and and the second one drives the relay coil. This way the relay is even further apart from the MCU (you basically put another layer of isolation between your MCU and the load of the relay)

Hope this helps...