Report for 5/14
We did the solenoid heat test (A1/B2), the conclusion is even with the minimum current solenoid is still too hot.
For A1, it need aroud 220mA (votage is around18.9V) to close the solenoid, and the solenoid will open again when the current down to 70mA (votage is around 5.5V), so during the heat test, first we adjust the current up to 220mA to close the solenoid, then we directly decrease the current down to 80mA (votage is around 6.5V), then we observe the temperature of the solenoid by FLIR camera.
The calibration of the camera has some problem, but we can see at the beginning (17:03), the temperature of A is 30.4deg in Fig.1, 1 hour later(18:20), the temperature up to 37.2 deg in Fig.2
For B2, it need aroud 260mA (votage is around20.2V) to close the solenoid, and the solenoid will open again when the current down to 110mA (votage is around 8.5V).We adjust the current up to 260mA to close the solenoid, then we directly decrease the current down to 120mA (votage is around 8.9V), then we observe the temperature of the solenoid by FLIR camera.
We can see at the beginning (15.31), the temperature of A is 30.3deg in Fig.3, 13 mins later (15:44), the temperature up to 38.1deg in Fig.4.The B2 solenoid heat very soon even with the minimum current.
A1 and B2 should have same structure except the direction, but the needed current is differenct, A1 solenoid heat much slow than B2 (1 hour vs 10 mins), we want to know the difference between A and B soleniod. It seems promising to decrease the heat if we know the difference(as LIGO 's soleniod).
We will try to test the other 2 solenoid and solenoid driver today.
We also found that the cooling fin might help to decrease the heat, so we will do the measurement again when we get the cooling fin.