Posted: 7/8/2013 8:46:47 PM EDT
| Ok lets say im hooking up a DC/DC SSR to a 24v 200W heater. Im seeing that I need a diode across the Load to keep the SSR happy. What Size Diode would I need? Is a 24v 5KW too large? |
| Anything in that range would probably be fine- even with an unrealistically high inductance for the heater, you're still only dissipating Edit: ~0.003 J, and in around 20 us. The specific thing you're looking for here, if you don't have something laying around already, is a TVS diode. Anything similar to here is probably fine: Digikey |
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Am I missing something here? The heater element would be pretty much straight resistive, right? Why would there be much/any inductance? A really long wirewound heater would have some small inductance, but probably not very much. I'm actually surprised the SSR wants external protection for a load like that- they've usually got a lot built in. |
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Am I missing something here? The heater element would be pretty much straight resistive, right? Why would there be much/any inductance? A really long wirewound heater would have some small inductance, but probably not very much. I'm actually surprised the SSR wants external protection for a load like that- they've usually got a lot built in. It's a Kapton element, so not wirewound, right? My guess is you're good to go. |
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Am I missing something here? The heater element would be pretty much straight resistive, right? Why would there be much/any inductance? A really long wirewound heater would have some small inductance, but probably not very much. I'm actually surprised the SSR wants external protection for a load like that- they've usually got a lot built in. It's a Kapton element, so not wirewound, right? My guess is you're good to go. Just looked up what these Kapton elements are. OP, you shouldn't need any diode for one of those. |
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Am I missing something here? The heater element would be pretty much straight resistive, right? Why would there be much/any inductance? A really long wirewound heater would have some small inductance, but probably not very much. I'm actually surprised the SSR wants external protection for a load like that- they've usually got a lot built in. It's a Kapton element, so not wirewound, right? My guess is you're good to go. Just looked up what these Kapton elements are. OP, you shouldn't need any diode for one of those. whoohoo! |