AUTOMATIC MACHINE FOR TESTING CAPACITORS AND NETWORKS 1189 



indicating relay K2 in an attempt to charge the defective unit, l)ut this 

 current will close relay K2 which in turn closes relay K3. This completes 

 the circuit through the "B" contacts of relays K3, K5, and Kll to close 

 memory relay K4. The closure of relay K4 prevents the memory test 

 I relay KG from closing the "go" calibration indicator relay K5, thereby 

 heaving contact "C" open on relay K5 and no power is applied to the 

 "acceptance solenoid" K7 circuit, which rejects the unit under test. 



IMPEDANCE — • TEST CIRCUIT OPERATION 



The impedance test is made with a 15-kc circuit (see Fig. 9). One arm 

 of the circuit, composed of resistor R12 paralleled by capacitor C5 and 

 the imit under test, is compared with another arm, composed of resistor 

 Pvll, paralleled by capacitor C4 and either one of two resistance boxes, 

 R13 and R14 respectively, representing maximum and minimum im- 

 pedance limits. The detector consists of a balanced diode V2 with a 1-0-1 

 microampere sensitrol relay K24 connected between the diode cathodes. 

 If the impedance of the unit imder test falls within the limits for which 

 the resistance boxes were set, the acceptance solenoid will be energized 

 to accept the unit under test. A product outside the preset limits is re- 

 jected because the acceptance solenoid is not energized. 



The circuit operation is discussed for the following four conditions 

 under A, B, C, and D. 



A. Impedance Test on Dual Unit Capacitors 



This test is made on capacitors to prevent shipment of resistance- 

 capacitance networks mislabeled as capacitors. Fig. 9 shows dual unit 

 networks connected to the test terminals. Capacitors to be tested are 

 connected to these same terminals. The greater than minimum test 

 cutout relay K18 is preset closed by the switching circuit K23. The 

 cammed memory reset timing switch S14 (normally closed) is opened 

 momentarily to clear relay K19, K20, and K21 at the start of the test. 



The sensitrol relay reset switch S16 is cammed shut momentarily to 

 reset the contactor on the sensitrol relay K24. With relay K2(3 open, the 

 "less than maximum" resistance box R13 is connected to the test cir- 

 cuit. If unit "A" of the dual unit capacitor under test is acceptable 

 product, the contactor on sensitrol relay K24 will close on contact "A", 

 which applies power to close and lock test No. 1 "less than maximum" 

 memory relay K19. Cam operated switch S13 applies power to close 

 relay K26 to connect the "greater than minimum" resistance box R14 

 into the test circuit. This resistance box is set on zero ohms when capaci- 



