Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
205 words
A system for electronically trimming the ohmic value of a printed circuit resistor without changing its physical dimensions, said system comprising: A a self-contained generating unit producing a low radio-frequency carrier having a predetermined frequency which is overmodulated by a sonic frequency to cause the carrier to be periodically interrupted to produce periodic bursts of radio-frequency energy at a repetition rate determined by the sonic frequency, whereby bursts of such energy are yielded at an output terminal; B a portable probe assembly independent of the generating unit including a tank circuit tuned to the carrier frequency, a tipped "Up" probe directly coupled by step-up means to the tank circuit and a tipped "Down" probe directly coupled by step-down means to the tank circuit; and C an extension cable connecting the output terminal of the generating unit to the tank circuit of the probe assembly whereby a corona discharge beam is projected from the tip of the "Down" probe, which beam when directed at the resistor acts to decrease its ohmic value, and a relatively low voltage having a high current density is established at the tip of the "Up" probe when it makes contact with the resistor to effect an increase in its ohmic value.
Claim 2
Independent Claim
205 words
A system for electronically trimming the ohmic value of a printed circuit resistor without changing its physical dimensions, said system comprising: A a self-contained generating unit producing a low radio-frequency carrier having a predetermined frequency which is overmodulated by a sonic frequency to cause the carrier to be periodically interrupted to produce periodic bursts of radio-frequency energy at a repetition rate determined by the sonic frequency, whereby bursts of such energy are yielded at an output terminal; B a portable probe assembly independent of the generating unit including a tank circuit tuned to the carrier frequency, a tipped "Up" probe directly coupled by step-up means to the tank circuit and a tipped "Down" probe directly coupled by step-down means to the tank circuit; and C an extension cable connecting the output terminal of the generating unit to the tank circuit of the probe assembly whereby a corona discharge beam is projected from the tip of the "Down" probe, which beam when directed at the resistor acts to decrease its ohmic value, and a relatively low voltage having a high current density is established at the tip of the "Up" probe when it makes contact with the resistor to effect an increase in its ohmic value.
Claim 3
Dependent Claim
23 words
A system as set forth in claim 1, wherein said carrier frequency lies in an operating range of about 200,000 to 300,000 Hz.
Claim 4
Dependent Claim
21 words
A system as set forth in claim 1, wherein said sonic frequency lies in the range of 2000 to 3000 Hz.
Claim 5
Dependent Claim
29 words
A system as set forth in claim 1, wherein said probe assembly is housed in a tube, and said cable is a coaxial cable whose outer conductor is grounded.
Claim 6
Dependent Claim
20 words
A system as set forth in claim 1, wherein said unit includes a crystal-controlled oscillator operating at said carrier frequency.
Claim 7
Dependent Claim
28 words
A system as set forth in claim 5, wherein the tank circuit is formed by a tank coil in parallel with a capacitor tuned to the carrier frequency.
Claim 8
Dependent Claim
25 words
A system as set forth in claim 6, wherein said step-up means is in a multi-turn coil of high inductance coupled to the tank coil.