Electronic indicator

An electronic frequency indicator for a radio frequency receiver having a dial plate comprising a plurality of light emitting diodes distributed across the dial plate at desired frequency increments, means providing a variable DC voltage which varies with frequency, a source of regulated DC voltage, voltage divider means connecting each of said diodes to said regulated source and establishing a different voltage at one terminal of each diode, first and second transistor means of opposite conductivity type connected in circuit with each of said diodes and responsive to the voltage established at said terminal and to said variable DC voltage for varying the current through each of said diodes from a minimum to a maximum and back to a minimum level corresponding to a range of frequencies whereby only one diode is activated at any time but successive individual diodes are activated and previously activated diodes are deactivated as the frequency is varied.

An electronic frequency indicator for a radio frequency receiver having a dial plate comprising a plurality of light emitting diodes distributed across the dial plate at desired frequency increments, means providing a variable DC voltage which varies with frequency, a source of regulated DC voltage, voltage divider means connecting each of said diodes to said regulated source and establishing a different voltage at one terminal at each diode, the voltage at the diode located at successively higher frequencies being a higher voltage, first and second transistors of opposite conductivity type connected in shunt with each of said diodes and responsive to the voltage established at said terminal and said variable DC voltage for varying the current through each of said diodes from a minimum to a maximum and back to a minimum level corresponding to a frequency range from a lower frequency to a higher frequency, voltage dropping means connected in circuit with each of said second transistors whereby a plurality of light emitting diodes are activated at any one time.