SSRs: So many kinds

[Raul]

Phase Angled, Pulsing, Zero Fired, Three Phase, there's even on called standard.

I get the Pulse vs Standard Standard has to be energized the whole time to complete the high voltage circuit and then breaks the circuit when 3VDC power to the SSR is cut. The pulsing type switches from on to off based on receiving a signal pulse and defaults to open when powered down entirely.

I'm looking to drive a series of Water Heater Elements at various levels of energy output by using SSRs to cycle in response to a thermocouple input.

I think I want a zero fired standard configuration SSR, but I'm unsure.
Driving the SSR would be an Ardunio open sourse controller or maybe PIDS both of which put out 3 volts to run the SSR they are in circuit with.

Also I'm thinking that I only need an SST for each hot lead and not the neutral that combined with a dual pole throw switch should effectively isolate the heater elements.




Any wisdom from the gathered minds about relays?

 

[KMoffett]

Standerd AC SSR: The output will turn on any time the input LED is turned and the AC voltage is beyond (+ or -) zero. It will remain on for the completion of one half of the AC cycle after the LED is turned off.

Zero crossing AC SSR: The output will turn on when the input LED is turned and only at the start (zero crossing) of the half cycle output AC voltage. It will remain on for the completion of one half of the AC cycle after the LED is turned off.

The advantage of the zero-crossing SSR is less switching noise. The disadvantage is that it will only conduct for full half cycles.

The advantage of the standard SSR is that it will conduct for partial half cycles. Phase-angle switching or time proportioning pulsed. The disadvantage is that is will generate switching noise.

The standard SSR will allow more precise temperature control on low heat capacity (low volume) systems. On high heat capacity systems there is not a lot of difference.

Ken

 

[Raul]

Thank you.
Standard is is.