Comments for Electronic Thermometer Project by LM35 and LM3914 at http://www.circuit-projects.com , comment 0 to 17 out of 17 comments http://www.circuit-projects.com Sat, 10 May 2008 00:34:39 +0100 FeedCreator 1.7.2 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_81 can i have the codes? - buddy Mon, 07 Apr 2008 20:17:10 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_56 Hi, i´ts me again. I´m trying to get these values: 600mv, 900mv, 1200mv and 1500mv so i can measure up to 150°C. I reduced R3 and R4 to 1k2 and R2 to 1k, and i can get 1500mv, 1200mv and 900mv. But i cant get 600mv in the wiper of POT 2. What should i do? Thanks - Alex Mon, 10 Mar 2008 20:35:47 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_54 Hi they arae 330 ohms and 75 ohms - marok Sat, 08 Mar 2008 06:08:13 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_53 Hi! I just want to ask what the 330R and 75R are... - Caleb Sat, 08 Mar 2008 04:21:47 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_52 try decreasing the R2 R3 and R4 values. Lets see what will happen - cremer Tue, 04 Mar 2008 05:46:11 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_51 I cant get a range of 500 mv to 1500mv with the 1k trimpot. What should i change? Thanks - Alex Mon, 03 Mar 2008 23:54:04 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_49 I searched for parts but couldn't find out any sensor in this range. National has a sensor which measures maximum 200°C. You can check out National Semiconductor Temperature Sensor Handbook http://www.national.com/appinfo/tempsensors/files/temphb.pdf - cremer Sun, 02 Mar 2008 09:43:49 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_48 Do you know what sensor is capable of measures 250°C? Thanks - Alex Sat, 01 Mar 2008 16:54:14 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_47 You should change the ref voltage values shown in the schematic (90mV, 190mV, 290mV and 390mV). Starting from 490mV to 1500mV. I think it is not possible to read 200 °C by using LM35DZ because it doesnt give a linear output at the values greater than 150 °C - cremer Sat, 01 Mar 2008 00:08:05 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_46 Hi. The LM35DZ measures up to 150°C. What voltages do I need for a thermometer from 50°C to 150°C? Can the LM35DZ in some way measure 200°C? - Alex Fri, 29 Feb 2008 23:34:24 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_39 I wonder if you could substitute an LM34 (Fahrenheit) directly? It appears to have the same scale division as the LM35 (10mV/F). - Bill Wed, 20 Feb 2008 14:05:18 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_37 thanks for all, now i wiil try it in my college,s laboratory! - ilham afandi Wed, 20 Feb 2008 04:26:43 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_36 hi . . I am using the lm35dz sensor to measure the body temperature by connected to ETH 256C AMP . Am not getting the result output from the AMP . hope you e mail me Thanks - aziz Tue, 19 Feb 2008 23:26:10 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_35 Take a look at the schematic. The LM35 output is scaled 10mV/degree C. Look at the reference voltages on the three stages U!-3 and see how they are scaled (90,190,290,390 mV). If you want the highest reading to be 1000 mV, then you could add more stages (a really long bar graph!) or you could adjust for different reference voltages (250, 500,750,1000 mV) on pots 2,1,3,4 respectively. - Alan Sun, 17 Feb 2008 13:00:04 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_14 What resistor values should I change If i want to make the range from 0 to 100c? I'm sorry, I only know how to solder and I do not know how to recompute the circuit. - Rens Tue, 15 Jan 2008 12:42:34 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_8 hello I want to do this thermometer too please write the result for me man.. It will be nice if you send some photos of the circuit also. good luck :) - math Sat, 29 Dec 2007 17:17:04 +0100 http://www.circuit-projects.com/index.php?option=com_content&task=view&id=106&Itemid=52#pc_7 I decide to make this thermometer for the Girl i love and she wanted it for her project in university and God help me if will not work! Pray For me! LOL! - MEHDI Sat, 29 Dec 2007 11:03:53 +0100