Circuit arrangement for applying a temperature stabilized voltage to a voltage sensitive component

Claim 1

In a tuning circuit arrangement having a plurality of predetermined resonant frequencies, each in response to a corresponding tuning voltage furnished at a tuning output, a temperature-compensated system for furnishing said tuning voltages at said tuning output, comprising, in combination, a plurality of sources of tuning voltage, corresponding in number to said plurality of resonant frequencies; a plurality of switching transistors, each having an emitter connected to a corresponding one of said source of tuning voltage, a collector and a base, each for furnishing the corresponding one of said tuning voltages at said collector in response to a control signal at said base; electronic step switch means having a plurality of switching outputs, for furnishing said control signal at a selected one of said switching outputs upon external activation; first connecting means connecting each of said switching outputs of the base of a corresponding one of said switching transistors; a plurality of first diodes each having a first electrode connected to the collector of a corresponding one of said switching transistors, and a second electrode, the voltage across each of said plurality of first diodes varying as a determined function of temperature; second connecting means connecting all of said second electrodes to a common line; a temperature compensating circuit element having a first electrode connected to said common line and a second electrode connected to said tuning output, the voltage across said temperature compensating circuit element also varying as said determined function of temperature upon flow of current therethrough; and biasing means including a source of electric energy having two terminals and a conductive impedance element connected between said common line and one of said terminals of said source of electric energy, said biasing means connected to said temperature compensating circuit element for causing a current flow through said temperature compensating circuit element opposite in direction to the current flow through said first diodes and through said conductive impedance element, whereby the change in voltage across said temperature compensating circuit element as a function of temperature compensates for the corresponding change in voltage across any of said first diodes, the voltage at said tuning output thereby constituting a temperature compensated tuning voltage.