Solar Off Grid.  PV Solar Matched to Heating Element .

Author	Message
Murphy's friend Guru Joined: 04/10/2019 Location: Australia Posts: 662	Posted: 08:31am 14 May 2023         phil99 said   Yes, as long as the switching 'on' time is short enough to prevent excessive burning and the 'off' time long enough to extinguish the arc. Well, maybe. All thermostats are not created equal. If the contacts are slow to open or/and the opening distance is insufficient, it will create a DC arc when the contacts *open*. Once the arc is established, 'off' time no longer plays any role as long as there is solar power and a load to feed it.
Confused Newbie Joined: 02/05/2023 Location: Ireland Posts: 17	Posted: 11:29am 14 May 2023       Hello Davo99,              Yes, It was the Arduino board and the caps that I was referring to. I just wanted to get as close to what you  used and any other unit you used.                                                              JS.
phil99 Guru Joined: 11/02/2018 Location: Australia Posts: 2257	Posted: 12:39pm 14 May 2023         Quote   phil99 said   Yes, as long as the switching 'on' time is short enough to prevent excessive burning and the 'off' time long enough to extinguish the arc. Well, maybe. All thermostats are not created equal. If the contacts are slow to open or/and the opening distance is insufficient, it will create a DC arc when the contacts *open*. I worded that poorly. I should have said the 'on' and 'off' times of the MOSFET. The MOSFET 'on' time needs to be short so that if the thermostat opens while it is on you want the MOSFET to switch off before the arc damages the contacts. The MOSFET 'off' time needs to be long enough to ensure the arc has extinguished and prevent the arc re-striking. Having the thermostat switch the gate or gate power supply is the safer option.
Murphy's friend Guru Joined: 04/10/2019 Location: Australia Posts: 662	Posted: 03:15pm 14 May 2023         phil99 said   Having the thermostat switch the gate or gate power supply is the safer option. Understood, that is exactly what my system does.
Confused Newbie Joined: 02/05/2023 Location: Ireland Posts: 17	Posted: 09:49pm 14 May 2023       Davo99,         With what the lads are saying and what you say in your long post. In there any modifications you'd make.  Any chance of a simple diagram.                                   J.S