Transistor stops switching power after a few seconds/minutes

[laingsoft]

I've been trying to control an animatronic Christmas tree, but I've run into a problem I can't figure out.


I have three transistors that are controlling the three motors of the tree. The base is connected through a resistor to the GPIO pin of my Raspi. The Collector is connected to the ground, and the emitter is connected to the ground of the motor.

The same setup is being used to control the lights as well.

The problem that I have been having is that for whatever reason, the first pin that you seem to set high works for only a few minutes/seconds, then slowly stops working. After that, the other two transistors will work fine indefinitely. Once you turn the power off and allow the board to sit for a while with no power, the transistors all begin to work again.


Is there a problem with my current setup?

 

[Hermaphroditus]

Re: Transistor stops switching power after a few seconds/min

Given I am drunk right now I am not sureI can answer confidently, but it sounds like it may be a capacitance issue. Tried changing transistors yet?

 

[laingsoft]

Re: Transistor stops switching power after a few seconds/min

Never mind, seemed to have fixed it.

Turns out when you turned the motor on, it pulled on one of the wires on the motor.. Then when I pulled the board out, the wires touched and it started working again.

 

[grossaffe]

Re: Transistor stops switching power after a few seconds/min

Never mind, seemed to have fixed it.

Turns out when you turned the motor on, it pulled on one of the wires on the motor.. Then when I pulled the board out, the wires touched and it started working again.

Reminds me of my old car's window. Was a power window, but after I lowered the window, it wouldn't go back up. Turned out that the window moving down yanked the cables out of the motor that was controlling it.

 

[Ishwhale]

Re: Transistor stops switching power after a few seconds/min

So simple that you geniuses can't figure it out.