electronic heater help - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st April 2003, 09:48 AM   #1
fezz is offline fezz  United Kingdom
diyAudio Member
 
Join Date: Feb 2002
Location: milton keynes, UK
Default electronic heater help

i want to design an electronic heater that heats water to a certain temprature (lets say 60c) and keeps it there, the problem is i really have no idea how to do this so could anyone point me in the right direction.

i was thinking of some sort of comparitor using a set resistor the same value as a thermister at that temprature
  Reply With Quote
Old 21st April 2003, 06:32 PM   #2
diyAudio Member
 
Join Date: Feb 2002
Location: Belgium
Something like a bridge and a comparator might do it, like you are proposing.

It all depends on what exactly you want. Are we talking about a plate to keep your coffee cup hot at the office, or to keep a swimming pool at temp?

Take a look at the TDA1023.
  Reply With Quote
Old 21st April 2003, 07:01 PM   #3
Ilianh is offline Ilianh  Canada
diyAudio Member
 
Ilianh's Avatar
 
Join Date: Oct 2002
Location: Montreal, Canada
Send a message via MSN to Ilianh
Do not forget to use hysteresis on your comparator otherwise (depending on the use) it might start/stop/start/stop at unwanted speeds (hearing fast clicking relays is not fun).

I remember making a Thermostat for pcb etching thing I made some times ago. It could give the temp in Kelvin and Celsius, had variable temp control and variable hysteresis.


I used a Temperature controlled current source that gives 1 uA at each kelvin degree I think.

Thats the IC http://cache.national.com/ds/LM/LM134.pdf

I remember choosing it because of its precision.

Use a similar Ic (national gives samples) with something like a 1k presision resistor that way at 100uA you have 100mV , a opamp to shift from Kelvin to celsius and a comparator with variable hysteresis.

Do not forget to keep the tracks and leads very short on that kind of circuits.
__________________
Time is the best teacher; unfortunately, it kills all its students
  Reply With Quote
Old 21st April 2003, 07:17 PM   #4
fezz is offline fezz  United Kingdom
diyAudio Member
 
Join Date: Feb 2002
Location: milton keynes, UK
this will be used to heat about a gallon of water, its to remove the crap from it (for other projects such as my computer water cooling)

i definatly need some sort of comparitor, ive decided that when the input is the same as the resistor value the output needs to be zero, but when the thermister value is different it gives a output of 1

seems like i need an or gate comparitor.

this wil be hooked up to a relay to control the temprature of the heater

is it possable that the temprature could go above the set temprature with this setup though?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New DHT heater Guido Tent Tubes / Valves 680 31st March 2014 05:20 PM
how to wire 6.3VDC heater on a heater with center tap (12.6V series, 6.3V parallel)? jarthel Tubes / Valves 9 14th April 2012 05:36 PM


New To Site? Need Help?

All times are GMT. The time now is 09:08 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2