tag:blogger.com,1999:blog-582219234592513124.post1068870632842453371..comments2023-11-21T23:09:42.770-05:00Comments on Electronics projects and tutorials: The op-amp as a comparator : temperature change detection circuitTesthttp://www.blogger.com/profile/10476755884474865744noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-582219234592513124.post-35149425445642693222014-03-04T23:00:00.195-05:002014-03-04T23:00:00.195-05:00Instead of having the 5V reference on the (+) inpu...Instead of having the 5V reference on the (+) input, you could duplicate the voltage divider with a 10k resistor and another thermistor. That way, when the thermistor on the (-) input is hotter, the op-amp output would go high. To drive a relay, you would have to use a transistor because the op-amp cannot provide enough current. Have a look at that picture : http://i.stack.imgur.com/Oarz3.gifTesthttps://www.blogger.com/profile/10476755884474865744noreply@blogger.comtag:blogger.com,1999:blog-582219234592513124.post-35347771283680568162014-03-04T22:46:59.597-05:002014-03-04T22:46:59.597-05:00Could you explain how to activate a relay when one...Could you explain how to activate a relay when one thermister is hotter than the other? Thanks<br />Anonymoushttps://www.blogger.com/profile/11141291929572026770noreply@blogger.com