# Solid State Relay - 40A (3-32V DC Input) (COM-13015) **URL:** \ **Category:** Sparkfun\ **Created:** [11 March 2020 03:32 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408 "2020-03-11T03:32:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Core](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/core/32/57_2.png) [@Core](https://forum.core-electronics.com.au/u/Core)\ **Post date:** [11 March 2020 03:32 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/1 "2020-03-11T03:32:09Z")
This is a placeholder topic for [**“Solid State Relay - 40A (3-32V DC Input)”**](http://core-electronics.com.au/catalog/product/view/sku/COM-13015) comments. ![](https://core-electronics.com.au/media/catalog/product//s/o/solid_state_relay_-_40a __3-32v_dc_input___ com-13015__01.jpg) A solid state relay (SSR) allows you to control high-curent AC loads from lower voltage DC control circuitry. Solid state relays have several advantages over mechanical relays. One such advantage is that they can be switched by a much lower voltage and at a much lower current than most mechanical relays. Also, because there’s no moving contacts, solid state relays can be switched much faster and for much longer periods without wearing out. [**Read more**](http://core-electronics.com.au/catalog/product/view/sku/COM-13015) ---
**Author:** ![Colin113088](https://avatars.discourse-cdn.com/v4/letter/c/d6d6ee/32.png) [@Colin113088](https://forum.core-electronics.com.au/u/Colin113088)\ **Post date:** [11 March 2020 03:32 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/2 "2020-03-11T03:32:11Z")
Hi im after a solid state relay dimrail mounted 24vdc coil switching 24vdc load l. Can you please suggest what ones you have and how much. Would be much appreciated. Regards Colin Dow ---
**Author:** ![Dion267210](https://avatars.discourse-cdn.com/v4/letter/d/6f9a4e/32.png) [@Dion267210](https://forum.core-electronics.com.au/u/Dion267210)\ **Post date:** [7 March 2024 07:20 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/3 "2024-03-07T07:20:03Z")
Hi there, do you supply or recommend a heat sink to go with Solid State Relay - 40A (3-32V DC Input)? > **[Solid State Relay - 40A (3-32V DC Input)](https://core-electronics.com.au/solid-state-relay-40a-3-32v-dc-input.html?registered=1)** > > A solid state relay (SSR) allows you to control high-curent AC loads from lower voltage DC control circuitry. Solid state relays have several advantages over mechanical relays. One such advantage is that they can be switched by a much lower voltage... ---
**Author:** ![Robert93820](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@Robert93820](https://forum.core-electronics.com.au/u/Robert93820)\ **Post date:** [7 March 2024 08:03 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/4 "2024-03-07T08:03:03Z")
Hi Dion These have a very low ON resistance hence virtually no voltage drop. This equates to near zero power dissipation within the relay itself so no heatsink is normally required or used. Be aware these are for switching AC loads only. They will not switch DC. Cheers Bob ---
**Author:** ![Dion267210](https://avatars.discourse-cdn.com/v4/letter/d/6f9a4e/32.png) [@Dion267210](https://forum.core-electronics.com.au/u/Dion267210)\ **Post date:** [7 March 2024 10:22 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/5 "2024-03-07T10:22:20Z")
Thanks Bob, that’s good to know. It will help me save on space in my project. I am also aware of their application to AC, my project involves 10A/240V load. I have used a similar SSR in another project but it had a built in heat sink. regards Dion ---
**Author:** ![Michael](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/michael/32/3545_2.png) [@Michael](https://forum.core-electronics.com.au/u/Michael)\ **Post date:** [8 March 2024 00:28 UTC](https://forum.core-electronics.com.au/t/solid-state-relay-40a-3-32v-dc-input-com-13015/7408/6 "2024-03-08T00:28:05Z")
Hi @Dion267210 - i can confirm these _rarely_ need heatsinking. However, if you’re sure you need it, i know jaycar have them: [https://www.jaycar.com.au/heatsink-to-suit-sy4084-sy4086/p/SY4085](https://www.jaycar.com.au/heatsink-to-suit-sy4084-sy4086/p/SY4085)