I'm using a relay like the one in the picture, controlled by an Arduino. I basically use it for turning mechanically on/off a circuit, when i have 0 as constant output from a series of values that describe a sinewave.
The system does what i expect, but every time that the sinewave cross the 0, it gives an input to the relay.
The input is so short that it doesn't trigger its status... this is perfect for what i want, but i don't know if this stress applied to the relay might brake it in the long run.
right, i should be more precise...
the arduino is comunicating with the DAC of a circuit via SPI. No waves from Arduino itself... it just gives the values to the DAC which then generates the wave.
The entire system have not be designed to be switched on/off by software (i need to automatize the process and save the battery). So, for controlling mechanically the ON/OFF of the circuit i added the relay, connecting it with a digital pin of arduino.
In the arduino firmware i figured out how to turn the relay OFF when the values of the wave are equal to 0 (so there is not real output), this work very well.
The problem is that since the values describe a wave that goes between positive and negative values, the 0 is "touched" for each period of the wave.
Apparently this give no problems, because the relay doesn't turn the circuit off, but i see that one of the LED of the relay module blinks according to the frequency i set, and the relay makes some noise with a pitch that vary also according to the frequency.
The relay is placed between the circuit and a 9V battery, so no much current going on there, but I don't know if this stress might brake the relay.
Here an approximate schematic... if it can help...