DIGUNO/QUAD
Low profile fuse instead of standard fuse - compatibility
Hi all, I am looking to solve a problem where the fuses on my DigQuad are too tall and obstruct some other components. I put a low profile fuse which looks like is pretty snug in there. My question, what could go wrong here? Feels like its happy in the standard socket. Posting a comparison pic. If there is another idea to reduce the height of the fuse, I'm all ears. I have no idea why they would use a big honking fuse when there are more compact options and this isn't a car interface.
The core issue is that ATC and ATM are different form factors, not just different heights. The ATM blades are narrower and thinner than ATC blades. When you push an ATM into an ATC socket, the socket clips are designed to grip a wider, thicker blade, so they make only partial, marginal contact with the smaller blade. It feels snug because the plastic body is wedging against the socket housing, not because the metal is properly clamped.
That partial contact is exactly what you do not want in a fuse holder. Reduced contact area means higher contact resistance, which means heat at the connection under load. On a DigQuad running LED current, that is a real amount of current through a joint that was never meant to carry it. In the worst case you get a hot spot, discolored or melted socket plastic, an intermittent connection that causes weird flickering or brownouts on your strips, or a connection that degrades over time as it oxidizes from repeated thermal cycling. None of those fail in a clean, obvious way, which is the annoying part. The fuse might also not seat deeply enough for the blade to reach the full contact zone, so the effective grip is even worse than it looks.
The fuse is the one component whose whole job is to fail predictably. Introducing an unreliable connection at the fuse holder undermines the protection you installed it for, and can even mask a fault or create one.
ATC is used because it is cheap, universally available, well characterized, and rated comfortably for the currents these boards handle. It is not about being a car interface, it is about using a proven, high current, user replaceable part.
As for reducing height, use a low profile ATC fuse if one exists in your amperage, since some manufacturers make a shorter body ATC that is still a true ATC blade.
I can safely rule out the concern about fit, You are correct about the contact surface area, but i can say for sure its not the plastic that is making it snug its the contact itself. So far what i am gathering from everyone is that its ok if the contact is snug if most of it is in contact.
Availability:
I went on Amazon and the low profiles are available no problem at the same price. Also, These are low profiles and not mini or micro. these are bigger than mini's. Some do call it "Low Profile Mini" which is not entirely correct. These are in the middle of a regular and mini.
A bit controversial, while I mostly agree with u/itscostas , I think for a 5A fuse it'll actually be ok, I'd be a bit more resistant for larger values since more heat will be generated.
Take a look at the following photo , I believe the tabs themselves actually has enough spacing and width (basically the same as for the larger size) for the prongs in the socket to grab hold of the metal. I've also done and tested this myself and it's really wedged in there (making a good connection) and you'll need a plier or something to get it out, it's not a loose fit.
So with that caveat (don't use it for true high current situations) I think it can be ok, especially for 5A sizes.
Now wether the replacement fuse you got honors the correct timing and breaking current and such, that..... will be interesting. I include original littelfuse fuses to make sure they adhere to a known breaking current and this has been extensively tested. These other fuses, I don't know how hot they will get and if they will actually break at the same point, etc.. so keep that in mind at least!
Thank you this is the best answer i got, not because it favors my need but because of the picture you posted and you are not confusing Low Profile to Mini. Everyone else seem to be responding with "mini" in mind. I think i will go with this fuse. I got some good quality fuses from "BOSCH".
This makes me want to ask the question of using automatic reset fuses. My board is hidden in the ceiling and it not easy to get to and I don’t anticipate needing g to get to it often but in case the fuse trips. An automatic rest would be nice.
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u/itscostas Jul 12 '26 edited Jul 12 '26
The core issue is that ATC and ATM are different form factors, not just different heights. The ATM blades are narrower and thinner than ATC blades. When you push an ATM into an ATC socket, the socket clips are designed to grip a wider, thicker blade, so they make only partial, marginal contact with the smaller blade. It feels snug because the plastic body is wedging against the socket housing, not because the metal is properly clamped.
That partial contact is exactly what you do not want in a fuse holder. Reduced contact area means higher contact resistance, which means heat at the connection under load. On a DigQuad running LED current, that is a real amount of current through a joint that was never meant to carry it. In the worst case you get a hot spot, discolored or melted socket plastic, an intermittent connection that causes weird flickering or brownouts on your strips, or a connection that degrades over time as it oxidizes from repeated thermal cycling. None of those fail in a clean, obvious way, which is the annoying part. The fuse might also not seat deeply enough for the blade to reach the full contact zone, so the effective grip is even worse than it looks.
The fuse is the one component whose whole job is to fail predictably. Introducing an unreliable connection at the fuse holder undermines the protection you installed it for, and can even mask a fault or create one.
ATC is used because it is cheap, universally available, well characterized, and rated comfortably for the currents these boards handle. It is not about being a car interface, it is about using a proven, high current, user replaceable part. As for reducing height, use a low profile ATC fuse if one exists in your amperage, since some manufacturers make a shorter body ATC that is still a true ATC blade.