Contactor Power Characterization

Owned by Jenna Kong
Last updated: Aug 18, 2023
2 min read

Setup:

  • Multimeter

  • BK Precision Power Supply

 

Connector Pinout
Set-up (From left to right: Multimeter, Power supply, contractor)

 

The multimeter was connected in series from the positive from the power supply to the positive of the connector to measure the max current, and also in parallel with the HV contractor to confirm the relay had closed.

 

Initial Power for Relay ON:
Max current: 2.0A

Voltage: 8.5V

 

To remain ON:

Voltage: >=7.0V

Voltage (V)

Current (A)

Power (W)*

Voltage (V)

Current (A)

Power (W)*

15.00

0.10

1.50

14.00

0.12

1.68

13.00

0.13

1.69

12.00

0.14

1.68

11.00

0.15

1.65

10.00

0.15

1.50

9.00

0.18

1.62

8.50

0.18

1.53

7.88

0.20

1.58

7.29

0.21

1.53

7.20

0.23

1.66

7.00

0.22

1.54

*To determine power, Voltage is multiplied by Current.

Purple highlights the max of each column

  • The multimeter was used to measure the current surge to close the relay, measuring a max of ~1.5A

  • However, current-limiting the power supply, the contractor would only shut when the max is set to 2.0A

    • Assume the current spikes to >1.9A and<2.0A to close the relay