8 switch relay controller

[njafari]

hey whats going on? I am using the Pi 2 with a SainSmart 8-Channel Relay Module and i am trying to light up some LED diodes and for some reason the switches are working but there is no voltage coming out. I am using a program that i found on this video but i don't know what command to use to use to send out a voltage can you please help?

[texy]

Hi and welcome to the forum.
Show a circuit diagram of how you have the diodes connected to the relay, with the power source.
The diodes would not get power from the relays directly, but from an independent source.
Texy

[BMS Doug]

When you say the switches are working, do you mean that the relays energise (click on)?

If so then I think you have mistaken the way that the relays work, they simply make an electrical contact between switch positions.

You would need to put a voltage onto the common contact of the relay, which would then be switched to either the normally closed (when the relay is off) or normally open (when the relay is on) contacts.

[davidcoton]

Before you just add a power supply, each LED also needs a resistor to limit the current. Otherwise its first switch on will also be its last.