THICK-FILM RESISTOR TRIMMING DEVICE Russian patent published in 2009 - IPC H01C17/22 

FIELD: electrical engineering.

SUBSTANCE: proposed device comprises first reference voltage source (1), comparator (2), resistance metre (3), ADC (4), voltage absolute value separation unit (6), comparator (17), second reference voltage source (8), shift register (6), monostable multivibrator (7), elements AND (8-1) to (8-n), DAC (12), flare discharge generator (12), switch (14), working electrodes (14-1) to (14-n), fitting resistor (15) and substrate holder (16), additional electrode (18) and third power supply (19). Radiating cone vertex of every electrode is located at fixed distance from surface of resistor (15) that decreases with increasing order number of working electrode (14-1) to (14-n), and adds to increasing accuracy and efficiency of trimming which displays at larger degree in the region of minor resistance increments. Device uses multiplying DAC (10), second reference voltage source (9) (to automatically set flame discharge power depending upon resistive film evaporation temperature). It comprises also switch (13), additional input and output, third reference voltage source (19), least voltage selection unit (11), comparator (17), reversing shift register (6) and discharge repeated switch-on unit (5).

EFFECT: higher accuracy and efficiency of trimming.

1 dwg