Homebrew PCBs

The transistor is being used as a diode. I’ve seen this on amplifiers to monitor the power transistors and adjust the bias so it don’t go into thermal runaway.  In all heater circuits I have dealt with we always used a temperature control with a thermocouple. These withstood the higher temperatures . they also had some form of high limit protection in case of a shorted thermocouple or controller failure.if the thermocouple failed open the controller simply shut the heat off altogether.

 

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Sunday, January 01, 2017 2:12 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: Temp upgrades of lam's HOW high is high heat conditions

 

  

A transistor with two of three legs soldered together makes a temperature probe. Is 

the temperature inside of lam too hot? Google for temperature probe circuits like I 

do for other projects.