Miller Electric T60 Manuel de l'opérateur télécharger pdf (Page 64)

technical reference

36 Synrad Firestar t-Series operator’s manual

Controlling laser power

Warning

serious

personal

injury

Always use shielded cable when connecting your PWM Command

signal source to PWM Input / PWM Return inputs. In electrically-

noisy environments, long lengths of unshielded wire act like an

antenna and may generate enough voltage to trigger uncommanded

lasing.

Figure 3-3 Representative Firestar t-Series waveforms

Firestar t-Series lasers are designed to operate at Command signal base frequencies up to 25 kHz; however,

the choice of PWM frequency depends on the user’s speciﬁc application. In the majority of laser applica-

tions, the UC-2000’s default Command signal frequency of 5 kHz has proven to work well. When con-

sidering Command frequencies at 5 kHz or below, please review Marking/engraving operation later in this

section. For high-speed motion applications that cannot tolerate any ripple in the optical beam response

but still need adjustable power levels, we recommend the use of higher PWM frequencies, up to 25 kHz

maximum. At 25 kHz, the laser’s optical beam response no longer follows the Command input and is very

nearly a DC value with just a small amount of ripple present.

Command signal

2.00 V M 50.0µs Ch1 1.24 V

Ch1

Representative optical output pulse

80% PWM duty cycle at 4.8 kHz

2.00 V M 50.0µs Ch1 1.24 V

Ch1

50% PWM duty cycle at 4.8 kHz

Representative optical output pulse

The modulated Command signal applied between Pin 9, PWM Input, and Pin 1, PWM Return, of the

User I/O connector on the RF power supply has three basic parameters: signal amplitude, base frequency,

and PWM duty cycle. By changing these parameters, you can command the beam to perform a variety of

marking, cutting, welding, or drilling operations.

The ﬁrst Command signal parameter, signal amplitude, is either logic low—corresponding to laser beam

off, or logic high—corresponding to beam on. The laser off voltage, typically 0 V, can range from 0.0 V to

+0.8 VDC while the laser on voltage, typically 5 V, can range from +3.5 V to +6.7 VDC.

Base frequency, the second parameter, is the repetition rate of the PWM input signal. The standard base

frequency is 5 kHz, which has a period of 200 µs. Maximum PWM frequency is 25 kHz.

1 2 ... 59 60 61 62 63 64 65 66 67 68 69 ... 133 134

Pas de commentaire

Miller Electric T60 Manuel de l'opérateur Page 64