Hello everybody.
I'm not very good with electronics so i need some help.
I bought from DealExtreme store this product ( http://www.dx.com/p/5v-4-channel-high-level-trigger-relay-module-for-arduino-red-157213#.U4wMOijgzqs ). As you can see there are connectors VCC, GND, IN1, IN2, IN3, IN4 and COM,GND (which are connected with a jumper) and I'm not sure how to connect it with an external 5V power supply and Arduino Yun .
Thanks in advance for any help.
You just need 7812 to activate relay. You can connect 12 vcc to turn on relay. where as you can use 5v from Power section unit
In1,in2,in3,in4 you can connected to digital IOs.
GND to GND
VCC to 7812 ic out. check the data sheet if the input says 5v you can give it from arduino yun itself. if they say 9v-12v you can use regulator ic 78XX .
usually 12 v recommended for relay
The relay has coilvoltage of 5 volts, 12 volts will burn the coil.
There is also an optocoupler (PC 817), perhaps thats the reason why COM and GND are connected together.
Look in the datasheet http://www.mycomkits.com/reference/Songle_SRD(T73)_Relay.pdf
Dielectric strenght coil to contact are ONLY 1500 volts.
Do not use this for switching mains current.
Pelle
I managed to connect everything properly.
From external power supplay I connected the +5V and GND with relay board VCC and GND, removed the jumper, and connect the Arduino GND with COM pin on relay board.
What do you mean, "Do not use this for switching mains current"?
Are these relays can not be used in order to control the devices connected to the common voltage of 220/240V ?
have you checked relay they used?? Is vcc 5v only??? Check coil voltage and contact voltage.
Info from DX page:
And I tested it with an input of 3.4V to 6V (properly worked turned on and off relay)