Test UC3843/3842

 https://jestineyong.com/uc3842-test-circuit/

https://fareedish.blogspot.com/2014/11/tester-ic-pwm-uc3843-untuk-smps.html

https://www.electronicrepairegypt.com/uploads/3/9/0/1/3901930/how_to_easily_make_your_own_uc3842__pwm_ic_tester.pdf