This circuit was obtained in an Electronics World of 1968. The operational amplifiers ones are types of the time, no longer used today. The circuit responds from less than 20 Hz.
For the component values used in thisf this circuit, the frequency can be adjusted between 740 Hz and...
We found this circuit in an old European documentation. Transistor TR1 can be BC548 and TR2 can be...
This circuit can be used in broilers, greenhouses, drying chambers to regulate the temperature in a simple...