I want to upgrade my heated bed. I currently have a 400w silicone heated bed running through my azteeg x3 at 24v. Heat up times are OK… But I want them to be better. I have a large heated bed. The heat spreader is 17" x “17” x 1/8" aluminum. I am thinking of running it at 120v. I have heard positives (simplicity) for using an SSR. But other have stated a larger MOSFET is really what should be used for a PID controlled bed.
I am no electrical expert by far. I am thinking of using an 800w 120v silicon heater to lower the duty cycle and increase heat up times. Can someone give me some guidance on how an electrical novice like me could build and implement an off board 120v MOSFET based controller to take input from the azteeg. Any help is appreciated.
@Eclsnowman , a mosfet is a terrible idea. SSR works just fine, and is, as you stated, by far the simplest solution.
I’m running a 1000W bed over a SSR, no problems. PID works perfectly.
@Rien_Stouten thanks. I also know others using them with no issue. How big is your bed at 1000w. Do you run into issues at higher power? Thermal distortion during heat up? Layer banding during heat cycles once at temp. I want to go high power. But I assume there is a sweet spot where too much power causes its own issues.
@Eclsnowman No issues at all. My bed is 400 x 400 mm. As I’m using PID, there is no big temperature fluctuation. Only small problem is a temperature overshoot at the beginning, which is easy enough to tune out, but I’m too lazy for that. I just want to print. As heating elements I am using two halves of a grill ( http://www.competenciaperfecta.com/reviews/p/733607-princess-classic-multi-grill/shop/) which gives me two nice, flat and sturdy heating surfaces, Drilled some holes in them, screwed them to my 4mm alu bed.
Glass windowpane 4mm thick on top, finished! (Checking the grill type I learned it’s not 1000 W but 1150W).
Heating the bed takes about 10-15 minutes.
Eric, SSR going only by AC or pulse current, by DC should be a MOSFET. If You need, can I make the wiring diagram. And yes, MOSFET ist more reliable vor quick switch (PWM? ).
@Maxim_Melcher that would be nice to have the circuit. I will try SSR first. But a good schematic might teach me some things that I should be learning. One thing I struggle with is knowing where to source electrical components… And which ones to pick (I assume like anything else some brands are the cheapest, some are high quality, and rarely are those two the same item).