Inkbird Solid Temperature Controller with Thermostat Function Review

I didn't use them on the project I bought them for because the relays were more efficient. I may be using them in a lower circuit soon, but I have to say. The heatsink was designed by someone who either didn't know thermodynamics or just didn't care. For heat to reach the upper fins, it must first pass through a thin cross-section. This throttles the flow of heat, making the heatsink less efficient.

Update: It's been about 3.5 years since they were installed. The one below works best. The load is constantly around 17.5A when on. Whatever happened, it failed when on and the terminal melted a bit. For additional cooling, the case is equipped with an 80mm fan. I'll probably strip more of the wire and wrap it around the screws for better contact. Original: I have no idea if this device is actually rated for 40A but I only need it for a 25A load. Intentionally overrated based on YouTube videos…

If you look at a site like Digi-Key you can find similar solid state relays in the $50 range. On Inkbird website (you can buy them directly there) inkbird.shop/products/ssr?variant=13851338047551 the price is $5.59 with free shipping! So you have to be wondering where they cut corners to sell them for 1/10th the price of a "standard" SSR. The unit I bought seems to work fine, although I've only tested it with a 250w load so far, around 2 amps. . At that level, the voltage drop was 0.98VAC, so…