Weird solenoid unexplainable oscillation

[little_carlos]

Hello guys, im having some troubles with a solenoid that im trying to control
im trying to make a solenoid oscillate using a 555 timer, the timer output goes to tip31c and it controls a relay, when i dont connect the solenoid, everything works as how i want, at 1hz, the relay activates at the speed it should be, but when i connect the solenoid, it starts to oscillate at a high frecuency as well as the relay, both start to oscillate at a high speed, anyone knows what is happening?
both relay and solenoid has their own flyback diode, the power supply is 12v 2amps capable, the solenoid is 12v 200mA, it does work ok, ive tested it without the 555 timer, im trying to use it as a piston to move a little box.
any known of what is happening?

[AF6LJ]

With what you have provided to work with, my first stab at this problem would be that the 555 is being spiked by the current draw from the solenoid.
Try running the 555 from a separate supply, or a lower regulated voltage from the same supply source.

As a side note;
Grounding becomes a big deal in these kinds of circuits.
If the ground / common lead is shared between the 555 and the relay / solenoid noise on the ground line can cause this kind of stuff to happen.

[little_carlos]

i did what you said, i used 2 different power supply's and now it works properly

[AF6LJ]

Now what you might try is bringing your ground leads back to one point in the circuit where the - lead of your supply will be connected.
Do the same with the + connections.
If it starts acting up, you need to decouple the 555 in some manner.
You can do this by running your circuit off a higher voltage; say 15V or 18V and run the 555 off a 12V regulator.

Depending on your circuit you could keep the +12V and down-regulate the 555 V+ to 8V. The regulator will provide the decoupling.
The 555 timer is picky when it comes to having a clean supply to run from.