Micro BEC 6-60V to 5V blows up when connected through rocker switch

Other Hardware General Electronics
1

Hello, community.
I have encountered a strange problem with a simple rocker switch.
When the switch was used to connect a voltage regulator (Mateck BEC) to a 24V power source, the BEC would instantly blow up. The rocker switch would short both wires, positive and negative. I tried about 6(!) times in a row with new BECs and other switches and got the same result - the Mateck BEC would instantly blow up as soon as I turned on the rocker switch.

When the BEC was connected directly to the battery using an xt60 connector, it worked fine.

I tried another BEC with the same wiring and it worked correctly as expected.
In conclusion - I was able to bypass this Mateck BEC problem using a BEC from a different manufacturer, but I am still very curious to know what the physical background of this behavior is. I assumed that pressing the rocker switch is the same as connecting to the battery using an xt60, but (WEIRD) this is not the case.

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2

There are two types of switch.

  1. Make before break
  2. Break before make

Looks like you got the wrong sort.

2 Likes
3

Also have you considered that rocker switch?

You seem to have wired it up as if it were a single throw double pole switch. Have you checked it with a continuity meter if this is actually the case? The rocker switches I have come across are not wired like this.

4

Thanks for the reply.
It seems that the term "make before break" refers to switches with 3 or more positions? Whereas my switch has 2 positions.

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5

Put your multimeter in continuity mode and test all switch contacts between each other in both positions.

6

So then it looks like the problem is that you are switching both the power and ground. This could leave the voltages floating, and so causing the damage.

I would advise you connect the ground like you do on the circuit without the switch, and only switch the power through your rocker switch.

PS. Nice looking construction you have there.

7

Thank you.

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I tried to break the circuit in different ways: positive and ground, and both poles at the same time, but the result was the same sad.

There is another strange behavior of this BEC: my project is a pan-tilt motorized head, which is powered by a remote control side, and then power and signal go through a 30m twisted pair cable.

The motorized head uses the same type of BEC as a voltage regulator with the same 6s (24V) power supply, and there were no problems - everything works as expected. The rocker switch breaks the whole circuit, including the motorized head, but this does not damage the BEC at the far end of the cable, only the near one.

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