Looking for feedback on Circuit Board to Prevent Overvoltage

Juz89

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Hi,

After coming across a post asking about over voltage protection on devices specifically following the failure of a Buck converter i decided to post a design i had been playing with a while ago. I have since created a prototype PCB rated to 5amps and proved its function.
Basically what this circuit board will do is if greater then 5.3v (This voltage can be changed by changing 2 resistors) is detected on the input side it will essentially short circuit the + to - causing the on board fuse to blow.
In actual testing what i have found is that once that voltage limit is reached it drops the output power to approx 1.2v for a period of approx 1 sec before blowing the fuse.

These boards could also be used to protect 12v systems by just changing 2 resistors in manufacturing.
There was some feedback within chat last night about removing the fuse to reduce the footprint size which could be done but you would just need a fuse placed on the input side of the board. Doing this would also allow the removal of the Screw terminals and allowing wire to be soldered directly to the board and being covered in adhesive heat shrink for example.

These boards would be $10 each which i believe to be a decent price compared to the potential of replacing things that have been supplied power greater then designed to handle.

My questions are
Is there any interest within this community for such a board?
Is there any improvements anyone can suggest on the design?

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AAH

I love blinky lights :)
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I would fatten up the power traces and to make it more universal as 5v and 12v mark the resistors r1, r2 etc and have a table on the board for the values for 5v and 12v.. If you do make it universal then change to Vin and Vout potentially. I'm also a fan of having mounting standoffs. You could also have some holes of about 2.5mm or so diameter outside of where the screw terminals go so that it could be mounted to fly leads. And finally furthering that and with regards to a convo between darylc and yourself in chat the other night you could put similar sized pads to break out the fuseholder to an inline waterproof style ATO so that the entire assembly could be waterproofed.
 

Juz89

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Dec 10, 2015
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Middlemount
I would fatten up the power traces and to make it more universal as 5v and 12v mark the resistors r1, r2 etc and have a table on the board for the values for 5v and 12v.. If you do make it universal then change to Vin and Vout potentially. I'm also a fan of having mounting standoffs. You could also have some holes of about 2.5mm or so diameter outside of where the screw terminals go so that it could be mounted to fly leads. And finally furthering that and with regards to a convo between darylc and yourself in chat the other night you could put similar sized pads to break out the fuseholder to an inline waterproof style ATO so that the entire assembly could be waterproofed.
I have now doubled the trace size and added the holes for the fly leads and to breakout the fuse holder.
I am thinking of not using a fuse holder due to the fact that most people will already have them fused by a distro board or similar. What i am thinking now is just having the break out pads for an external fuse and the end user will be able to configure it by either adding a inline waterproof fuse like you spoke about or using there distro board fuses by soldering a jumper on the board.
I will take on board about the mounting stand offs. I amm thinking the most common method of mounting will be in shrink wrap near the prop. The standard stand off size as far as i am aware is m3 which would increase the board size and may not be needed.
I think due to not everyone having the ability/equipment to solder 1206 smd resistors to offer a 5v and 12v or.as it will only be one resistor that will need to be changed so there maybe an option to have both resistors on the board and the end user to solder the jumper to the correct resistor for the voltage they wish to use
 
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Juz89

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Here are the revised designs after the feedback from @AAH. I have decided to keep the footprint smaller on the one that will potentially be put out in the weather and covered in heat shrink to create two different boards. Both boards will now protect 12 and 5v circuits depending on what jumpers the end user solders together. As Shown in the images i have added some more text to reduce confusion. The Heat shrink board has had the screw terminals and fuse holder removed and 2.5mm holes in there place. This will enable the wires to be directly soldered to the board. There is also a fuse solder jumper on this board to be joined by solder if using Distro board fuses.


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AAH

I love blinky lights :)
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I reckon the smaller board is the way to go. Easy to heatshrink it up or a 3D printed mount could be made if put into an enclosure. The smaller 1 also means it could be made into a nice tidy v-grooved panel and fit 18 under 100x100mm. Much easier when slapping down some solder paste and cheap as well.
 
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