This circuit was found in an Electronic Design from the 90s. The circuit uses a type J thermocouple that can measure from -50 to + 100º C. Power is provided by a 3 V lithium battery.
The frequency of this circuit depends on the crystal. The transistor supports a modern equivalent. We...
Indicated in Maxim's documentation from the 90's, this circuit has a gain of 40 dB and an output...
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...