Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



Thermistor Circuits
 

Last Updated: December 07, 2017 02:04 PM


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

10°C to 40°C Thermistor Thermometer -  The LT1789 is a micropower, precision instrumentation amplifiers that are optimized for single supply operation from 2.2V to 36V.  The quiescent current is 95μA max, the inputs common mode to ground and the output swings within 110mV of ground.  The gain is set with a single external resistor for a gain range of 1 to 1000 for__ Linear Technology/Analog Devices App Note, Mar 30th 2010

2-Wire Thermistor 0°C to 100°C Temperature Transducer with 4mA to 20mA Output -  The LTC1040 is a monolithic CMOS dual comparator manufactured using Linear Technology’s enhanced LTCMOS TM silicon gate process.  Extremely low operating power levels are achieved by internally switching the comparator ON for short periods of time.  The CMOS output logic holds the output information continuously while not consuming __ Linear Technology/Analog Devices App Note, Mar 30th 2010

50MHz Thermistor RMS to DC Converter using 5V Supply -  The LT1014 is the first precision quad operational amplifier which directly upgrades designs in the industry standard 14-pin DiP LM324/LM348/OP-11/4156 pin configuration.  it is no longer necessary to compromise specifications, while saving board space and cost, as compared to single operational amplifiers.  __ Linear Technology/Analog Devices App Note, Mar 30th 2010

5V Powered Thermistor Heating/Cooling Automatic Thermostat -  The LTC1040 is a monolithic CMOS dual comparator manufactured using Linear Technology’s enhanced LTCMOS TM silicon gate process.  Extremely low operating power levels are achieved by internally switching the comparator ON for short periods of time.  The CMOS output logic holds the output information continuously while not consuming __ Linear Technology/Analog Devices App Note, Mar 30th 2010

A Galvanically Isolated Thermistor Digitizer -  The LTC1799 is a precision oscillator that is easy to use and occupies very little PC board space.  The oscillator frequency is programmed by a single external resistor (RSET).  The LTC1799 has been designed for high accuracy operation (≤1.5% frequency error) without the need for external trim components__ Linear Technology/Analog Devices App Note, ,Mar 30th 2010

A Simple Circuit Thermistor Interface to an ADC -  App Note/ 1753 / Oct-03__ Maxim Integrated

Alarm Sounds At Freezing Temperatures -  This electronic hobby circuit below is designed to activate a beeper alarm, whenever the outside air temperature is below 0 degrees C (32F).  A 9v battery powers the hobby circuit.  The average 9ua current is so low that the battery should last for many years . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

AN75 - Circuitry for Signal Conditioning and Power Conversion -  Linear Technology AN75 __ Designed by Jim Williams - Mar 1st, 1999

AN98 - Signal Sources, Conditioners and Power Circuitry Circuits of the Fall, 2004 -  Linear Technology AN98 __ Designed by Jim Williams - Nov 19th, 2004

Anticipator Improves On Earlier Idea -  EDN Design Ideas:  05/24/2012   A self-biasing thermistor circuit had an overall dominant thermal/electrical time constant as small as 25 msec but had a significantly rounded response following a square (thermal) input pulse of 100 msec; the source was a pulsed blue LED.  A single-op-amp-based “anticipator-like” circuit generated a more faithful picture of the actual input excitation, and improved on the circuit described in a previous Design ideas (Reference 1).  The lowpass filter in Figure 1, with an RC time constant of approximately 25 msec, models the circuit. __ Circuit Design by Nicholas Lockerbie, Scottish Universities Physics Alliance, Glasgow, Scotland

Anticipator Speeds Signal Settling to a Final Value -  03/17/11  EDN Design Ideas:  Use a differentiator circuit to predict the final value of an exponential signal.  The circuit in this Design idea anticipates, or jumps instantly to, the final voltage of an input-signal change.  it relies on the fact that the intended input signal changes exponentially with a known time constant.  This circuit was adapted from a 1970s-era instant-reading electronic thermometer, which displayed a patient’s body temperature within seconds after a thermometer probe was placed under the patient’s tongue.  it exploits the fact that the temperature probe’s exponential thermal response-time characteristic is known.   __ Circuit Design by Tim Regan, Linear Technology App Note, San Jose, CA-- 03/17/11

Battery-Powered Freezer Alarm -  A typical freezer can contain hundreds of dollars with of food.  if the device becomes unplugged or if the door is left open too long, the food inside can quickly become spoiled.  The hobby circuit below is a battery powered alarm system, which is attached . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006

Circuit Improves On Earlier Idea -  EDN Design Ideas:  05/24/2012   A self-biasing thermistor circuit had an overall dominant thermal/electrical time constant as small as 25 msec but had a significantly rounded response following a square (thermal) input pulse of 100 msec; the source was a pulsed blue LED.  A single-op-amp-based “anticipator-like” circuit generated a more faithful picture of the actual input excitation, and improved on the circuit described in a previous Design ideas (Reference 1).  The lowpass filter in Figure 1, with an RC time constant of approximately 25 msec, models the circuit. __ Circuit Design by Nicholas Lockerbie, Scottish Universities Physics Alliance, Glasgow, Scotland

Circuitry for Signal Conditioning and Power Conversion -  Linear Technology AN75 __ Designed by Jim Williams - Mar 1st, 1999

Determine balancing current for the LTC3305 lead-acid battery balancer -  EDN Design Ideas:  06/29/2016    Delve into PTC thermistor intricacies to optimize battery-balancing designs __ Circuit Design by LTC Design Note

Freeze Alarm -  I chose an accurate thermistor from Keystone as the temperature sensor for this circuit.  This device has a very specific resistance at a particular temperature.  According to the data sheet for the thermistor, the device will have a resistance of 361K at zero degrees C, which is the freezing point of water.  The thermistor is wired into a simple bridge circuit, which uses 1% resistors.  The bridge is connected to a very low power voltage comparator.  The circuit forms a switch circuit, which changes state, when the resistance of the thermistor reaches a certain value.  At zero degrees C the voltage at the non-inverting input of the comparator exceedsCircuit Solution by David Johnson P.E.-May, 2006

Freezer Over-Temperature Alarm -  This circuit turns on a beeper whenever the inside temperature of a freezer is greater than zero degrees Centigrade.  The circuit draws only a few microamps from a 9 volt battery.  it uses a glass bead thermistor accurate to 1 degree C.. . . Circuit by David A. Johnson P.E.-November, 2014

Freezing Temperature Alarm -  The circuit below is designed to activate a beeper alarm, whenever the outside air temperature is below 0 degrees C (32F).    A 9v battery powers the circuit.    The average 9ua current is so low that the battery should last for many years.. . . Circuit by Dave Johnson P.E.-November, 2014

Heat Sensor -  The Thermistor, or NTC (Tony van Roon's Negative Temperature Coefficient) of 10K, is a standard type.  Most types will work.  The one in the diagram is a 10K model made by Fenwal (Tony van Roon's #197-103LAG-A01)  __ Designed by Tony van Roon  VA3AVR

Linearize thermistors with new formula -  EDN Design Ideas:  03/03/2014     Optimize thermistor performance at any preferred temperature __ Circuit Design by Mark Biegert

LTC Design Note: Determine balancing current for the LTC3305 lead-acid battery balancer -  EDN Design Ideas:  06/29/2016    Delve into PTC thermistor intricacies to optimize battery-balancing designs __ Circuit Design

Pseudologarithmic thermistor signal conditioning spans wide temperature range -  6-Jan-05 EDN Design Ideas:  Given its low cost, small size, robust construction, accuracy, versatility and sensitivity, it's no wonder that the thermistor rates as one of the most popular temperature sensors available.  However, in some applications, a thermistor can exhibit too much sensitivity for wide-range temperature measurements __ Circuit Design by Stephen Woodward, University of North Carolina, Chapel Hill, NC

Sensor to Display, Built with Thermistor, 12-Bit ADC, 89S52 & LED Display -  This is my student assignment for the class "Designing Microprocessor Based instrumentation".  The board demonstrates the use of 12-bit ADC, writing c program with digital filtering and interface the LED display.  The reading provides 0.1C sensitivity.  The optional input of the ADC is available for exercise with other input signals or sensors.   __ Designed by Wichit Sirichote

Signal Sources, Conditioners and Power Circuitry Circuits of the Fall, 2004 -  Linear Technology AN98 __ Designed by Jim Williams - Nov 19th, 2004

Simple Circuit Anticipator Improves On Earlier Idea -  EDN Design Ideas:  05/24/2012   A self-biasing thermistor circuit had an overall dominant thermal/electrical time constant as small as 25 msec but had a significantly rounded response following a square (thermal) input pulse of 100 msec; the source was a pulsed blue LED.  A single-op-amp-based “anticipator-like” circuit generated a more faithful picture of the actual input excitation, and improved on the circuit described in a previous Design ideas (Reference 1).  The lowpass filter in Figure 1, with an RC time constant of approximately 25 msec, models the circuit. __ Circuit Design by Nicholas Lockerbie, Scottish Universities Physics Alliance, Glasgow, Scotland

Simple Circuit Thermistor Interface to an ADC -  App Note/ 1753 / Oct-03__ Maxim Integrated

Temperature-to-period provides linearization of thermistor response -  11/10/05 EDN Design Ideas:  Highly accurate pulsewidth varies with temperature __ Circuit Design by S Kaliyugavaradan, Anna University, Madras Institute of Technology, Chennai, India

Thermistor Preamp -  (spice design)  __ Designed by Rick 

Thermistor Thermometer: LCD Version -  This is the 2nd version of Thermistor Thermometer Project done by another group of my student.  The 1st version having 4-digit 7-segment LED shows the use of simple display device.  For applications that needs text display, this LCD version is more suitable and easy to adapt for many kinds of measuring devices.   __ Designed by Wichit Sirichote




Thermistor Circuits


HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy


Copyright  January, 1998 - December, 2017     David A. Johnson & Associates.  All Rights reserved. 


 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.