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Moderated Re: Circuits on 2 sides


 

Bertho,

? Funny story. :) But in my case I was hoping and also using my JST connectors, there was a way to reverse polarity. Of course putting together the project correct would be ideal, but in the past not all LED's are properly configured as far as polarity. Once the project is soldered up I have (only once or twice) had the polarity backwards. The easy fix would be to unplug a connector and re-plug it in opposite for the power feed. So far everything I have done has been soldered so it makes it a little harder to fix but not really that hard. But when I switch to plugs using JST connectors I was just curious if there was a trick for future use just in case. Like a few jumpers that could be swapped around. In the end I will just pay attention and color code with wire colors etc.

Dave

On 11/13/2020 10:35 PM, Bertho wrote:
One trick is if you have a three pin connector is to use the center pin for
positive and the two outside pins connected to ground. Then polarity does
not matter.

Another common thing on multipin strip connectors is to remove a male pin
and insert a dummy plug in the matching female location. If reversed, it
will not plug in.
That reminds me. A very long time ago we were manufacturing a product with
a 12 pin in line connector with a missing pin. It turns out that a square
toothpick fit perfectly as a plug for the female connector: Just push it
all the way in and cut it off flush.

We had an angry customer calling about our terrible quality: He said there
was even a piece of wood stuck in the connector and it took him a long time
to remove it. Then even worse he said, when he finally plugged it in there
was smoke coming from the PCB and it did not work. Of course he had plugged
it in backwards.
Bertho

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