1. A heater assembly for heating when ambient temperature drops below a set point temperature, said heater assembly comprising:
a laser;
a heater external to said laser;
a thermal transfer member positioned at least partially in thermal contact with said laser and said heater, wherein said heater heats said thermal transfer member and said laser to maintain said set point temperature for said laser when ambient temperature is below said set point temperature; and
a temperature sensor in thermal contact with said thermal transfer member for sensing the temperature of said thermal transfer member wherein said temperature sensor is mounted on a printed circuit board of a fiber optic transmitter.
2. The heater assembly of claim 1 wherein said heater is off when said ambient temperature is above said set point temperature.
3. The heater assembly of claim 1 wherein said heater is a transistor.
4. canceled
5. The heater assembly of claim 1 further comprising a thermally conductive material between said temperature sensor and said thermal transfer member.
6. Canceled
7. The heater assembly of claim 1 wherein said laser and said heater are mounted to a circuit board of said laser and said laser circuit board is mounted in a vertical manner to said fiber optic transmitter circuit board to economize space on said fiber optic transmitter circuit board.
8. The heater assembly of claim 1 wherein said thermal transfer member is positioned in between said laser and said heater.
9. The heater assembly of claim 1 further comprising a controller for determining when to increase and decrease the amount of heating by said heater based upon said set point temperature and said ambient temperature.
10. A heated laser assembly for heating a laser to maintain a set point temperature, said heated laser assembly comprising:
a transistor external to said laser;
a thermal transfer member in thermal contact with said laser and said transistor, wherein said transistor heats said thermal transfer member to maintain said set point temperature for said laser when ambient temperature is below said set point temperature; and a temperature sensor in thermal contact with said thermal transfer member for sensing the temperature of said thermal transfer member wherein said temperature sensor is mounted on a printed circuit board of a fiber optic transmitter.
11. The heated laser assembly of claim 10 wherein said transistor is off when said ambient temperature is above said set point temperature.
12. canceled
13. The heated laser assembly of claim 10 further comprising a thermally conductive material between said temperature sensor and said thermal transfer member.
14. canceled
15. The heated laser assembly of claim 10 wherein said laser and said transistor are mounted to a circuit board of said laser and said laser circuit board is vertically mounted to said fiber optic transmitter circuit board to economize space on said fiber optic transmitter circuit board.
16. The heated laser assembly of claim 10 wherein said thermal transfer member is positioned in between said laser and said transistor.
17. The heated laser assembly of claim 10 further comprising a controller for determining when to increase and decrease the amount of heating by said transistor based upon said set point temperature and said ambient temperature.
18. canceled
19. canceled
20. canceled
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Compounds of the formulae (IV-a) and (IV-b)
in which
R1 represents OR3,
R2 represents alkyl and
R3 represents alkyl.
2. Compounds of the formulae (IV-a) and (IV-b) according to claim 1,
in which
R1 represents OR3,
R2 represents C1-C6-alkyl and
R3 represents C1-C4-alkyl.
3. Compounds of the formulae (IV-a) and (IV-b) according to claim 1,
in which
R1 represents OR3,
R2 represents methyl, ethyl, n-propyl or n-butyl and
R3 represents methyl, ethyl, n-propyl, n-butyl or i-butyl.
4. Compounds of the formula (III)
in which
R1 is as defined above.
5. Compounds of the formula (III-a)
in which
R1 is as defined above.
6. Compounds of the formula (III-b)
in which
R1 is as defined above.
7. Process for preparing compounds of the formula (III),
in which
R1 is as defined above,
characterized in that compounds of the formula (II)
in which
R1 is as defined above
are reacted with ammonium carbonate and alkali metal cyanides or trimethylsilyl cyanide (TMSCN) in the solvent water.
8. Process for preparing compounds of the formula (III-a),
in which
R1 is as defined above,
characterized in that compounds of the formula (II)
in which
R1 is as defined above
are reacted with an alkali metal cyanide and ammonium carbonate in water.
9. Process for isolating compounds of the formula (III-a)
in which
R1 is as defined above,
characterized in that compounds of the formula (III) are treated with aqueous ammonia.
10. Compounds of the general formula (I)
in which
R1 represents OR3,
where
R3 represents alkyl.
11. Compounds of the formula (I) according to claim 9,
in which
R1 represents OR3,
where
R3 represents C1-C4-alkyl.
12. Compounds of the formula (I) according to claim 9,
in which
R1 represents OR3,
where
R3 represents methyl or ethyl.