Download Galvos specs

GMAX M2/M2T 9.5mm XY Open Frame Head
4.2.2.6 Current Cutoff Circuit
The circuit described below is sensitive to RMS current only and not coil
temperature. It is essential that the user perform the above calculations to
prevent malfunction or damage to the scanner.
WARNING
Should the current cutoff circuit cause the scanner to operate intermittently
the user should cease operation immediately and review his input drive
command.
There is a current cutoff circuit on each driver board which calculates RMS current in the
scanner coil and disconnects the driver when the current exceeds 1.7 amps RMS (square
wave input) and 1.42 amps RMS (sine wave) steady state for 30 seconds. The power
permitted at these currents must be calculated using the coil resistance at the galvo operating
temperature. The power at room temperature (25 °C) is calculated using a coil resistance of
4.65 ohms. At 100 °C, the power is calculated using a coil resistance of 6.05 ohms. Since the
circuit has a built in delay, the current may exceed these values for periods of time shorter
than 30 seconds. For instance, the circuit will permit 2.13 amps (square wave) for 13
seconds. This circuit should prevent coil damage under most long-term over power
situations, but does not eliminate the possibility of damage due to brief fault conditions
involving significantly higher currents. In summary, this circuit will not prevent damage
due to unusual fault conditions during tuning or system debug.
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