Automatic gain control system for cascaded transistor amplifier

• US 3,328,714 A
• Filed: 06/15/1964
• Issued: 06/27/1967
• Est. Priority Date: 06/15/1964
• Status: Expired due to Term

• Current Assignee: Eduard H. Hugenholtz
• Original Assignee: Eduard H. Hugenholtz
• Inventors: Hugenholtz, Eduard H.
• Application Number:
  US04/375,062
• Time in Patent Office: 1,107 Days
• US Class Current: 330/280
• CPC Class Codes: H03G 3/3068 Circuits generating control signals for both R.F. and I.F. stages

Claims

1. AN AUTOMATIC GAIN CONTROL SYSTEM FOR A CIRCUIT OF THE TYPE HAVING FIRST AND SECOND AMPLIFIER CIRCUITS, A SOURCE OF SIGNALS, MEANS APPLYING SAID SIGNALS TO SAID FIRST AMPLIFIER CIRCUIT, MEANS APPLYING THE OUTPUT OF SAID FIRST AMPLIFIER CIRCUIT TO SAID SECOND AMPLIFIER CIRCUIT, A DETECTOR CIRCUIT AND MEANS APPLYING THE OUTPUT OF SAID SECOND AMPLIFIER CIRCUIT TO SAID DETECTOR CIRCUIT, WHEREBY SAID DETECTOR CIRCUIT PRODUCES A DIRECT AUTOMATIC GAIN CONTROL VOLTAGE, SAID AUTOMATIC GAIN CONTROL SYSTEM COMPRISING MEANS FOR APPLYING SAID DIRECT VOLTAGE TO SAID SECOND AMPLIFIER CIRCUIT FOR DECREASING THE GAIN THEREOF AS THE AMPLITUDE OF SIGNALS APPLIED TO SAID DETECTOR CIRCUIT INCREASES, MEANS FOR APPLYING SAID DIRECT VOLTAGE TO SAID FIRST AMPLIFIER CIRCUIT FOR DECREASING THE GAIN THEREOF ONLY AS THE AMPLITUDE OF SIGNALS APPLIED TO SAID DETECTOR CIRCUIT INCREASES ABOVE A PREDETERMINED MINIMUM AMPLITUDE, AND MEANS RESPONSIVE TO A DECREASE IN GAIN OF SAID FIRST AMPLIFIER CIRCUIT FOR INCREASING THE GAIN OF SAID SECOND AMPLIFIER CIRCUIT, SAID MEANS RESPONSIVE COMPRISING DIRECT CURRENT CONDUCTIVE MEANS CONNECTED BETWEEN SAID SECOND AMPLIFIER CIRCUIT AND A POINT IN SAID FIRST AMPLIFIER CIRCUIT HAVING A POTENTIAL DEPENDENT UPON THE GAIN THEREOF.