Temperature responsive astable multivibrator

An oscillator circuit responsive to a predetermined ambient temperature, comprising:

• an astable multivibrator including a first transistor, and a second transistor connected at its input terminal to the output terminal of said first transistor through a first capacitor and at its output terminal to the input terminal of said first transistor through a second capacitor, each of said capacitors being connected between a pair of resistors for defining a pair of time constants, and at least one of said transistors being arranged to be exposed to an ambient temperature;
• a switching transistor for receiving at its input terminal an output voltage appearing at the output terminal of said first transistor and for producing an inverted output voltage at its output terminal with a predetermined time delay;
• and
• an additional capacitor responsive to the inverted output voltage from said switching transistor for applying a terminal bias voltage thereacross to said first capacitor and the input terminal of said second transistor at opposite voltage polarity relative to that of a terminal voltage appearing across said first capacitor, said additional capacitor having a predetermined capacitance value determined in such a way to turn off one of said first and second transistors in relation to said terminal bias voltage when the ambient temperature becomes the predetermined one.