Audio signal driven analog flame display

A system comprising:

• a base unit including an analog base unit controller circuit arranged to receive an audio input signal and generate an analog control signal that is responsive to the audio input signal;
• a control wire connectable to the base unit to distribute the analog control signal;
• and
• a flame display unit electrically connectable to the control wire to receive the analog control signal;
• the flame display unit including a combustible fuel source to generate an open flame;
• and the flame display unit including a proportional valve to control flow of fuel from the fuel source so as to controllably vary a height of the open flame responsive to the analog control signal during operation of the flame display unit;
• the flame display unit includes a flame control circuit arranged to receive the analog control signal and generate an analog valve position signal;
• and
• the flame control circuit is coupled to utilize the analog valve position signal to control electrical current in the proportional valve during operation, thereby producing an active flame show responsive to the audio input signal;
• and
• wherein the analog base unit controller circuit comprises:
• an input section to receive the audio input signal;
• a full-wave rectifier circuit coupled to the input section to rectify the audio input signal to form a rectified signal;
• a low-pass filter circuit coupled to the full-wave rectifier circuit to filter the rectified signal to form in interim signal, the low-pass filter having a roll-off frequency selected based on response characteristics of the proportional valve;
• and
• a current summing circuit to combine the interim signal with a predetermined DC offset voltage to form the analog control signal, for setting a minimum drive current in the proportional valve during operation.