Operating Instructions Dplmagic Marker Dplgenesis ... - ACI Laser

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Detailed Advanced Information Example 2 Conventional, diode-pumped marking laser, multimode Starting values: Pcw = 40 W f = 2000 Hz dt = 100 ns r = 35 · 10 -6 m This gives: and: 40 W PP = —————————— = 200,000 W P Pd = —————————— = 5.19 · 10 13 Wm -2 Summary It can be seen that the pulse power density on the material is higher with the DPL Magic/Genesis/Nexus Marker than with conventional, diode-pumped marking lasers in multimode operation. It does not rise linearly with the value of the continuous power. 13.4 Thermoelectric Air Cooling 13.4.1 Design 2000 s -1 · 100 · 10 -9 s 200,000 W (35 · 10 -6 m) 2 · π The design of the laser with the realisation of the highest peak pulse powers at low cw power enables the required pump output of the laser diode to be substantially reduced. This means that the heat generated and the dissipation power at the laser diode module are very low. The dissipation power which is turned into heat in the DPLMagic/ Genesis/Nexus Marker is about 25 W. This means that this important characteristic is substantially lower in comparison to conventional diode-pumped laser marking systems. For cooling and stabilising the temperature of the laser diode, the DPLMagic/Genesis/Nexus Marker can therefore do without a waterair cooling system without impairing the performance capability of the cooling. Modern thermoelectric air cooling by means of Peltier elements is used instead. 44 Operating Instructions DPLMagic/Genesis/Nexus Marker - 08/2006
Principle of operation of a Peltier element 13.4.2 Cooler Dimensioning Detailed Advanced Information Peltier, the French physicist, discovered in 1834 the effect that the temperature falls below the ambient temperature when current flows at the contact point of two touching metals. The efficiency of this effect has been increased enormously over the last few years by the use of modern semiconductor materials. A Peltier element consists of an n- and a p-conducting semiconductor leg. These legs are linked by a copper bridge. If a direct current flows through such an element, one side of the element cools and thus takes heat energy from the environment. This heat energy is then released again to the environment or a heat sink on the other side. The direction of the heat flow is reversed by changing the direction of the current. A high cooling capacity is achieved by combining several Peltier elements in a Peltier block. The individual elements are connected electrically in series and thermally in parallel. Cooling the laser diode The following boundary conditions apply to the dimensions of the cooler for the DPLMagic/Genesis/Nexus Marker: • minimum cold side temperature on the laser diode: Tk = 20 °C, • maximum dissipation power of the laser diode: Pv = 25 W, • maximum permissible ambient temperature: Tu = 35 °C. A cooler unit which fulfils these requirements is integrated into the DPLMagic/Genesis/Nexus Marker. A constant cold side temperature is maintained at the laser diode at an ambient temperature of T u = 35 °C with simultaneous full load operation of the laser (P v = 25 W). This requires the use of high performance Peltier blocks. Two Peltier blocks, each with 127 Peltier elements are used thermally in parallel for cooling the laser diode. The waste heat thus taken away from the laser diode is transferred to an aluminium cooler and released to the environmental air by means of a high performance fan. The dimensioning of the aluminium cooler (surface, volume etc.), the selection of a suitable fan and the implementation of optimal heat transmissions play a key role here. The thermal resistance, characteristic of the cooler module are determined to Rth < 0.1 K/W. Operating Instructions DPLMagic/Genesis/Nexus Marker -08/2006 45
Page 1 and 2: Operating Instructions DPLMagic Mar
Page 3 and 4: Table of Contents 1 Introduction ..
Page 5 and 6: Table of Contents 13.2.5 Laser Cont
Page 7 and 8: 1 Introduction 2 Important Informat
Page 9 and 10: 2.3 Symbols in the Document Warning
Page 11 and 12: Important Information Type plate Th
Page 13 and 14: Important Information General Infor
Page 15 and 16: 3 Brief Description 3.1 View of dev
Page 17 and 18: 3.4 Unpacking Brief Description The
Page 19 and 20: Brief Description Focussing NOTE! A
Page 21 and 22: 3.7 Electrical Installation 3.7.1 I
Page 23 and 24: Brief Description Connections for o
Page 25 and 26: 4 Initial operation 4.1 Checking th
Page 27 and 28: 5 Operation Operation All operating
Page 29 and 30: Care objective. In so doing, draw t
Page 31 and 32: 9 Fault Finding 9.1 General Faults
Page 33 and 34: Status/Error Trigger Message LoopSt
Page 35 and 36: 12 Technical Data Laser device Diod
Page 37 and 38: 13 Detailed Advanced Information De
Page 39 and 40: 13.2.1 Laser beam source 1 E[ev] E
Page 41 and 42: 13.2.4 Plane field objective Detail
Page 43 and 44: 13.2.6 Marking Software Detailed Ad
Page 45: 13.3.1 Pulse Power Density Detailed
Page 49 and 50: 13.5.1 Pulse Overlapping Detailed A
Page 51 and 52: Detailed Advanced Information Plast
Page 53 and 54: 14.2 Technical drawing M6 x10 deep
Page 55 and 56: 15 Index Index A Additional symbols
Page 57 and 58: Index O Objective .................
Page 60: 08/2006 - Marker DPLMagic/Genesis/N

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