1. A light-emitting diode (LED) drive circuit including a circuit that drives a light-emitting diode with a common connected cathode, said drive circuit comprising:
a first resistor having a first terminal connected to an anode of said light-emitting diode;
a first NPN-type transistor that has an emitter connected to a second terminal of said first resistor and that approximately determines a control current for emission of light in cooperation with said first resistor;
a second NPN-type transistor positioned parallel with said first resistor element that has an emitter connected to said anode of said light-emitting diode; and
a current supply, a level shifter, and a switch for selectively changing a voltage between a base-emitter of said second NPN-type transistor, that are positioned between a base of said second NPN-type transistor and said second terminal of said first resistor.
2. The LED drive circuit according to claim 1, wherein said level shifter comprises a third NPN-type transistor.
3. The LED drive circuit according to claim 1, wherein said switch comprises a second resistor, a first terminal of which is connected to a second NPN-type transistor side of said second resistor and a second terminal of which is connected to a constant-current source side of said second resistor, and a pair of wires connectesd at said first and second terminals of said second resistor; wherein a voltage drop is or is not produced at said second resistor depending on which one of said pair of wires is selected as active.
4. The LED drive circuit according to claim 3, wherein said switch further comprises at least one additional NPN-type transistor for activating one wire of said pair of wires.
5. The LED drive circuit according to claim 4, wherein at least one pair of said additional NPN-type transistors comprise said switch and said pair of said additional NPN-type transistors are connected, respectively, to said first and second terminals of said second resistor, and one pair of control input terminals are connected to said pair of said additional NPN-type transistors for control thereof.
6. The LED drive circuit according to claim 4, wherein said cathode of said light-emitting diode is commonly connected to a ground potential.
7. The LED drive circuit according to claim 1, further comprising a compensator providing a compensation circuit for compensating for an effect of said level shifter or said switch on said control current.
8. The LED drive circuit according to claim 1, further comprising an idle current produced at said light-emitting diode.
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. A syringe for taking up and discharging a fluid, comprising a cylinder, a piston portion slidably disposed in the cylinder, and an operating means connected to the piston portion for sliding thereof, the operating means projecting from a first end of the cylinder, the cylinder having an inlet and an outlet part for said fluid at a second end, wherein a sealing means is connected in a contamination-free manner to the cylinder in an area of the first end thereof and wherein the sealing means is of such a length that the sealing means may extend into the cylinder to an area of the second end of the cylinder and isolates the inside of the cylinder from the environment.
2. A syringe as claimed in claim 1, wherein said sealing means is arranged to form a seal between the inside of the cylinder and an inner end of the operating means extending into the cylinder.
3. A syringe as claimed in claim 1 or 2, wherein the sealing means is located substantially inside the cylinder.
4. A syringe as claimed in claim 1, wherein the sealing means has an open end into which the inner end of the operating means extends.
5. A syringe as claimed in claim 4, wherein the open end of the sealing means is connected to the first end of the cylinder.
6. A syringe as claimed in claim 1, wherein a guide sleeve is arranged at the first end of the cylinder to guide the operating means.
7. A syringe as claimed in claim 4 or 5, wherein the sealing means forms a piston-like portion at its end opposite to the open end, wherein the piston-like portion is movable by the operating means inside the cylinder, the piston-like portion sealingly engaging the inside of the cylinder.
8. A syringe as claimed in claim 4, wherein the open end of the sealing means is connected to the first end of the cylinder by being turned inside out around the edge of the first end of the cylinder.
9. A syringe as claimed in claim 1, wherein the sealing means is made of an elastic and sealing material.
10. A syringe as claimed in claim 1, wherein said syringe and sealing means are pre-sterilized.
11. The syringe of claim 10, wherein the syringe and sealing means are pre-sterilized by irradiation.
12. A syringe as claimed in claim 1, wherein the opposite end of the sealing means, at the inner end of the operating means, is movable and the open end of the sealing means is held still at the first end of the cylinder.
13. A syringe for taking up and discharging a fluid, comprising a cylinder, a piston portion slidably disposed in the cylinder, and an operating portion connected to the piston portion for sliding thereof, the operating portion projecting from a first end of the cylinder, the cylinder having an inlet and an outlet part for said fluid at a second end, wherein a sealing portion is connected in a contamination-free manner to the cylinder in the area of the first end thereof and wherein the sealing portion maintains the contamination-free connection to the cylinder when the piston portion is disposed at the second end of the cylinder and isolates the inside of the cylinder from the environment.
14. A syringe as claimed in claim 13, wherein said sealing portion is arranged to form a seal between the inside of the cylinder and an inner end of the operating portion extending into the cylinder.
15. A syringe as claimed in claim 13, wherein the sealing portion is located substantially inside the cylinder.
16. A syringe as claimed in claim 13, wherein the sealing portion has an open end into which the inner end of the operating portion extends.
17. A syringe as claimed in claim 16, wherein the open end of the sealing portion is connected to the first end of the cylinder by being turned inside out around an edge of the first end of the cylinder.
18. A syringe as claimed in claim 16, wherein the opposite end of the sealing portion, at the inner end of the operating portion, is movable and the open end of the sealing portion is held still at the first end of the cylinder.
19. A syringe as claimed in claim 1, wherein a first end of the sealing means is connected in a contamination-free manner to the cylinder and wherein a second end of the sealing means is connected to the piston portion.
20. A syringe as claimed in claim 13, wherein a first end of the sealing portion is connected in a contamination-free manner to the cylinder in the area of the first end thereof and wherein a second end of the sealing portion is connected to the piston portion.