in english
in-russian
AM-FM Transmitters and Bugs
 

Frost Alarm

 

Alarm

Notes:
The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead type thermistor is found in the Maplin catalogue. The 100k pot allows this circuit to trigger over a wide range of temperatures. A slight amount of hysteresis is provided by inclusion of the 270k resistor. This prevents relay chatter when temperature is near the switching threshold of this circuit.




Leave a comment
Your name: *
Your Mail:

Comment: *

 :)   ;)  :D
 :(  =)  ?)
 :ups:  :cool:  :bad:
 :like:  :angel:  :love:

Enter characters: *
captcha
Reload

1999-2010. cxem.net. All right reserved!