The following tables provide the highest Fill Fraction value obtained at various scan speeds and zoom levels for a particular Cambridge 6210H 3mm galvo controlled by a 671xx Class 1 servo.
- Scan Amplitude = 2V (or 4V if a differential input is employed). This corresponds approximately to field-of-view scanned using Scan Amplitude = 2.5V (or 5V with differential input) under ScanImage 3.0/3.5.
- For this particular galvo, measured Acquisition Delay = 100?s (Scan Delay = 200?s). These values were entered and held fixed -- i.e. the linear optimization regime was employed. This Scan Delay value is well above small-angle step response specification; a better tuned scanner/servo would likely perform better.
At the specified fill fractions, the temperature remained below 50°C during 1 hour of continuous scanning. The temperature had remained stable for at least 5-10 minutes at that point.
Values are color-coded as follows:
Red: Maximum safe value found (if any) is below the optimal fill fraction value determined for the linear regime (given in parentheses). In other words, thermal considerations are the limiting factor at this speed/amplitude.
Orange: Value represents the optimal fill fraction value determined for the linear regime. At that value, stable temperature was reached in the range of 40-50°C at 1 hr. Higher fill fractions, which would be in the nonlinear regime, were not tested and appear to be at risk of overheating.
Green: Value represents the optimal fill fraction value determined for the linear regime (or 0.819, whichever is lower). At that value, stable temperature was reached below 40°C at 1 hr. Higher fill fractions were not tested, but appear to be possible.
These results, of course, are provided as a reference only. They are in no way a guarantee.
Sawtooth Scanning
|
16° |
8° |
5.33° |
4° |
3.2° |
|---|---|---|---|---|---|
1 ms/line |
NONE (0.554) |
NONE (.621) |
0.585 (.640) |
0.621 (.640) |
0.640 |
2 ms/line |
0.706 |
0.759 |
0.787 |
0.819 |
0.819 |
Bidirectional Scanning
|
16° |
8° |
5.33° |
4° |
3.2° |
|---|---|---|---|---|---|
0.5 ms/line |
NONE (0.640) |
NONE (0.640) |
0.706 |
0.706 |
0.706 |
1 ms/line |
0.819 |
0.819 |
0.819 |
0.819 |
0.819 |
2 ms/line |
0.819 |
0.819 |
0.819 |
0.819 |
0.819 |
NOTE: Values above 0.819 were not tested.
Testing Conditions
- Temperature measured using Fluke 179 multimeter using Fluke 80BK-A temperature probe (Type-K thermocouple)
- Galvo was mounted on a standard aluminum mounting block (available from Cambridge Technology) which in turn was placed on a stainless steel shelf in a well-ventilated room/area
- Probe was fixed to exposed side of galvo can, towards the mirror, using thermal compound
- Baseline temperature for tests was ?24.5°C
- Optimal fill fraction fulfilling 'linear' condition was determined by eye - i.e. it was judged that ripple had sufficiently settled by the desired ramp start position