New 24v system for heated bed not heating any faster?

[Mjolinor]

They would, fuses are horrendously complex things and their design is really complicated and difficult to understand but whatever the fuse type given the choice of a fuse and a transistor with both in overload state then the transistor will always blow first when the fuse is the sort with a burnable link.

[DBFIU]

What do you suggest I do?

I love how fast this bed gets up to temp.

[Mjolinor]

I would just leave it. The PSU should be able to look after itself so if you are using a relay and it has been working so far then leave it. The only thing to watch with relays is the back EMF from the collapsing magnetic fields but I think that has been mentioned already.

If it fails then you just look at it as an opportunity to learn something new while you fix it, a plus in anyone's book.

[DBFIU]

Cool thanks for the tips.

By the way, I bought a bunch of Fotek SSRs, and they dont work, none of them. Yet the reprap forum says the Fotek SSR's should work as a DC relay. Mine say they are for AC, and dont work in DC power circuits? Not sure, do you happen to know what gives with the contradiction?

[Mjolinor]

AC SSRs probably use thyristors for switching, DC SSRs will use MOSFETS.

[Roxy]

AC SSRs probably use thyristors for switching, DC SSRs will use MOSFETS.

I think what this means is: The Solid State Relay will turn on... But it won't ever turn off because it needs the current to reverse to turn off the Silicon Controlled Rectifier. Right?

[Mjolinor]

I think what this means is: The Solid State Relay will turn on... But it won't ever turn off because it needs the current to reverse to turn off the Silicon Controlled Rectifier. Right?

The thyristor needs the current to drop to zero before it will open circuit once it is short.

[Roxy]

The thyristor needs the current to drop to zero before it will open circuit once it is short.

Right! That is what I thought. But I used the wrong term. I said 'Silicon Controlled Rectifier'. A Thyristor is two of those in parallel but pointed in opposite directions.