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General Category => Do-more CPUs and Do-more Designer Software => Topic started by: PLCwannabe on October 27, 2024, 12:42:40 AM

Title: Using analog output for pwm control of heater
Post by: PLCwannabe on October 27, 2024, 12:42:40 AM

  Can I safely use an analog output to trigger a solid-state relay for heater control? Relay is triggered at 3 -32 vdc. I want to use a 10 second on/off period,and I don't want to add a transistor output card for just this one output.


https://www.automationdirect.com/adc/shopping/catalog/relays_-z-_timers/solid_state_relays/gq-75-60-d-1-3

Consumption GQ-xx-xx-D-x-x models:   ≤ 8mA @ 260VAC GQ-xx-xx-A-x-x models: ≤ 13mA @ 32V

Title: Re: Using analog output for pwm control of heater
Post by: Controls Guy on October 28, 2024, 02:15:43 PM

Probably work as long as it's a current and not a voltage output.    Looks like the impedance is too low for a voltage output.

If it was me, I'd just buy an SSR that takes an analog input and phase-fires accordingly, so long as you can lose the zero cross (I think they still turn ON at zero cross and turn OFF at the point determined by the signal).   I've used Crydom pretty much exclusively for SSRs, and they at least used to have that.