Archive for June 21st, 2013

LinuxCNC + Mesa 7i76: Solid-state Relay Light

I intend to use solid-state relays to control things like extruder and platform heaters, so I wired a Fotek SSR-10 DD to the same output bit as the First Light test, with a random 12 V SLA battery providing power for the LED strip:

Mesa 7i76 with Fotek DC-DC SSR

Mesa 7i76 with Fotek DC-DC SSR

Nothing groundbreaking, but it’s always nice to confirm these things.

Note that the SSR must have a DC output, not the more common AC output, to control DC power. In effect, a DC-DC SSR is just an up-armored power FET with an optically isolated gate terminal.

Dan reports that the Fotek SSRs have just about exactly the internal build quality you’d expect for a cheap product from halfway around the planet. Although the specs would have you believe they operate from a 5 VDC source, that may not be the case. The 7i76 output pins switch the +24 VDC field power to the SSR, so it’s firmly turned on.


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