PCB Power (On/Off) Switch and Fuse Recommendation

Question

Hello All,

This is my first post here and admittedly, I am new to the Eagle CAD world. I recently hired a freelancer to convert a breadboard design to a PCB using Eagle and he specified a RDT1034 switch (3 pin) and I can not find a reasonable replacement. Can you point me to a good replacement/alternative?

He also placed a fuse after the switch and before the VI of the 3.3v voltage regulator. I'm also looking for a reference to a suitable fuse part number.

Thanks for your help!

genebren · Accepted Answer

Dave, It gets a little weird when you work with some people in remote locations and they are using older versions of the software. Depending on how you deploy your design, yeah the switch might not be necessary. If you are going to use a switch now, the one you linked to could be used if you are wiring it in remotely, as the footprint on the layout does not match with this switch. If you are intending to mount the switch on the PCB, you will need another switch. On the topic of fuses, it is still difficult to determine the value of the fuse that would be needed, without understanding the expected current draw. The line of fuses for use with this holder range from 40mA all the way up to 10A. You need to pick one that would cover your normal range of operation, which some headroom for inrush or other surges (within normal operation). I am a little ashamed to say this, but on low-voltage boards, like this, I do not usually install a fuse. If there were some regulatory requirements that needed to be met, I would, but for the most part that has not been the case. The protective device in most cases is the attached power supply. Most are capable of shutting down on an over-current situation. Good luck, Gene

genebren · Answer

Dave,

First off, welcome to the community. There are several active people here willing to help and be helped.

Switches are extremely plentiful in their size, shape and function. I could not find any info on RDT1034 part, so I am not sure that I can help you with this part. If you have more information, like a specification sheet, or even a snapshot of the switch in the schematic and layout, it might be able to help in understanding the form/fit/function that is needed.

The fuse is also problematic, in that fuses come in many varieties and have several parameters (trip/blow current, slow/fast blow, physical dimensions). Again, a better understanding of the design would be helpful to select a proper component (same as above, more information would help).

Good luck!

Gene

shabaz · Answer

Hi Dave,

You possibly don't need the fuse, because the diode inline (1N4148) doesn't support a lot of current anyway, and will probably blow open before the fuse does. What value was the fuse rated at?

PCB Power (On/Off) Switch and Fuse Recommendation

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