Shorting 5V to Ground

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JamesCoyle

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I'm using the 5V output on the Teensy 2 to power some LEDs. I have the LEDs wired with a resistor all in series between 5V and GND. The problem I have is how they are connected to the Teensy. I'm using a 3.5mm audio jack to allow the LED circuit to be plugged in when needed but this can lead to the 5V rail being shorted to ground for a second or so when the connector is inserted or removed while the Teensy has power. Will it cause damage to the Teensy over time and is there a relatively simple way to solve this issue?
 
A thought--you could put the resistor before the jack instead of after the plug. That way, the short will go through the resistor.

best,
Michael
 
It will short your USB-Connection:

schematic2.gif
 
Michael Ward said:
A thought--you could put the resistor before the jack instead of after the plug. That way, the short will go through the resistor.
Click to expand...

So I'm right in thinking any sort of load between 5V and GND should prevent any issues? I was thinking I could maybe put something like a 10k resistor across the leads of the port to add a load but then that would mean current would always be flowing with the jack disconnected which isn't ideal. I think desoldering the resistor and putting it inside the case might be the best option then.
 
Maybe I don't understand. 10K across the leads of the port (to ground from the output to the led?) wouldn't do anything about the short issue.
--Michael
 
Something like the following where the two switches represent the 3.5mm connector.
Ob51ycA.png

You were suggesting doing this:
JYpRK4i.png
Which would ensure there isn't a dead short.
 
Are you sure the tip and ring of the plug are shorting when inserted? In many of the 3.5mm jacks I'm familiar with, the tip (point) of the jack does not touch its contact until it's past the sleeve that contacts the ring.

There are some jacks that short the connections when nothing is plugged in. Or are you using a stereo jack or plug and using sleeve and ring instead of tip and ring?
 
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