The proposed device uses a combination of the variable and current transformer by means of varying the voltage in the primary side of the transformer. From the principle of electromagnetic induction, the secondary side of the transformer will produce a minimum and maximum rate of current necessary to meet the ampere trip rating of the circuit breaker under test. The device also uses a simple DC regulated power supply for the contact resistance tester.
The device is limited to a maximum produced current of 200A only with the circuit breaker rating of less than or equal to 100AT (ampere trip) that the device can only test. Continuous operation is not advisable because the device can inject or produce high amount of current making the small devices inside to easily heat up, thus, causing failure or damage to the device.