Connect through a relay?
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Hi,
In the printer that I am mounting, the hot bed, which has a high consumption, works through a relay, and the relay is the one that connects to the Duet board (v3 mini) ...
And I am weighing, after the negative experience, if this same solution could not be applied to the Heater Cardride. To avoid possible short-circuit problems, even to more components ... such as fans.
Happy new year!!!!!!!!! in advance.
Only 2/3 cups, take care.... -
Do you mean a real relay (with a coil and a flappy contact), or a solid state relay?
A real relay might be rated for 1E6 switching cycles. At 25Hz (say), that's only 11 hours of heater use. It will also be noisy. At the default 250Hz it will only be an hour before you've exceeded the rated lifetime, but actually it probably can't run that fast (say, 10mS switching time, you're limited to 50Hz).
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undefined droftarts referenced this topic
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@achrn think its a Solid State Relay
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@peirof
Be aware that you need special type of solid state relay to switch DC power to a heater, not a common / generic SSR.It may also limit the PWM frequency you can use, as many simple DC SSRs are rather slow switching & continuous fast switching may cause problems or overheating.
Just using a fast-acting or semiconductor rated fuse of the appropriate rating is likely cheaper and simpler, if you are concerned about wiring faults.
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When a SSR or a mosfet fails they often keep the output on and heating up uncontrollably.
I’m considering using 2-3 relays just for safety reasons.
The normal coiled ones are enough if you use them just for turning the power off. They would switch on when the printer goes on and off when there is a failure or the printer goes off.
The only caveat is that I’m using a WiFi power socket so I can turn off the whole printer over Wi-Fi and NodeRED and I would not need any additional wiring.
