Method and system for communicating pulse width in a night vision system power system
View Patent ↗A night vision system including a power system having a low voltage unit coupled to a high voltage unit. The low voltage unit includes a low voltage controller and a low voltage table correlating step values to pulse widths, the low voltage controller obtaining a desired pulse width and accessing the table to obtain a step value. The high voltage unit including an opto-isolator for receiving the step value from the low voltage controller, a high voltage controller response to the step value accessing a high voltage table correlating step values to pulse width to obtain a pulse width, the high voltage controller generating a control pulse in response to the pulse width.
1. A night vision system comprising:
a power system having a low voltage unit coupled to a high voltage unit;
the low voltage unit including a low voltage controller and a low voltage table correlating a plurality of step values to a plurality of pulse widths, the low voltage controller obtaining a desired pulse width and accessing the table to obtain a step value;
the high voltage unit receiving the step value from the low voltage controller, a high voltage controller response to the step value accessing a high voltage table correlating step values to pulse width to obtain a pulse width, the high voltage controller generating a control pulse in response to the pulse width.
2. The night vision system of claim 1 wherein:
the high voltage table is a copy of the low voltage table.
3. The night vision system of claim 1 wherein:
the high voltage unit includes high voltage power electronics responsive to the control pulse.
4. The night vision system of claim 1 wherein:
the step value is represented using 9 bits.
5. The night vision system of claim 4 wherein:
the step value is transmitted with a steering bit.
6. The night vision system of claim 1 wherein:
the pulse width represented by the step value ranges from 1250 us to 300 ns.
7. The night vision system of claim 1 wherein:
the step value corresponds to pulse widths ranging from a maximum value and decreasing logarithmically to a minimum value.
8. The night vision system of claim 7 wherein:
the pulse widths decrease from the maximum value to the minimum value in decrements of 2.5%.
9. A method for controlling a night vision system, the method comprising:
in a low voltage unit, obtaining a desired pulse width and accessing a low voltage table correlating a plurality of pulse widths to a plurality of step values to obtain a step value;
transmitting the step value to a high voltage unit;
in the high voltage unit, accessing a high voltage table correlating step values to pulse width to obtain a pulse width, the high voltage unit generating a control pulse in response to the pulse width.
10. The method of claim 9 wherein:
the high voltage table is a copy of the low voltage table.
11. The method of claim 9 wherein:
the step value is represented using 9 bits.
12. The method of claim 11 wherein:
the step value is transmitted with a steering bit.
13. The method of claim 9 wherein:
the pulse width represented by the step value ranges from 1250 us to 300 ns.
14. The method of claim 9 wherein:
the step value corresponds to pulse widths ranging from a maximum value and decreasing logarithmically to a minimum value.
15. The method of claim 14 wherein:
the pulse widths decrease from the maximum value to the minimum value in decrements of 2.5%.