Hi I have an SPI RedPower laser source , its 1064nm and 250 w its application is for cutting thin stainless steel.
The unit has developed a fault , I can power up the diode pump externally and shoot a beam but the unit is in fault mode, I am thinking the seed laser which acts like a band pass filter for the diodes has a fault on the control pcb .
I have laser experience in lumonics and Rofin yags plus Rofin co2 slab and Q switched lasers but my experience in diode pumped is limited.
My question is how do I control the seed laser to switch the beam on/off , I would build a circuit to modulate the seed . The laser has only one function to switch on/off the beam at a fixed power.
Any advice appreciated
Peter
Maybe you can try these ways.
- Inspect the Control PCB: Look for any damage or short circuits.
2.Control the Seed Laser: Use a transistor or MOSFET to control the power supply to the seed laser.
3.Use PWM: If possible, use Pulse Width Modulation (PWM) to adjust the power.
Hi Andy
Appreciate the response to my question.
Unfortunately I have very limited information on the unit SPI was taken over by Trumph and they don’t have the circuit details .
I have inspected the pcb,s and had a look around with my storage CRO but when the unit goes into alarm mode most active components are shut down.
I can see the seed laser and there is an opamp with unity gain driving it so I will attempt to drive it externally.
What waveform and frequency should I drive the seed . Is the mark space ratio 1:1
As mentioned if this was an acoustic optic modulation I could drive it but don’t have experience with diode p7mped seed laser .
Peter
[quote=“Peter_Klos, post:3, topic:1478”]
Trum
Hi Peter,
Here are some general suggestions that might help, but please note that these are based on typical practices and may not be specific to your laser model:
1.PWM: Implement with a frequency of 1kHz to 10kHz. Consider a duty cycle of around 50% (1:1 mark space ratio) for initial testing.
2.External Driving of Seed Laser: Externally driving the seed laser could be a viable approach if it’s currently driven by an opamp with unity gain. A stable DC signal is generally recommended for consistent operation. The wavelength of 1064nm is common for such applications, but verify this with your laser’s specifications.
3.Protection Measures: Consider incorporating protection circuits like current limiting resistors and voltage stabilizers to prevent overcurrent and overvoltage conditions, which could lead to equipment damage.
Andy
Hi Andy Thanks I will do some experimenting.on the driving of the seed and install on my laser rail.
I always take precautions with lasers I have lamp pumped Yags and have eye protection goggles and my power supply has current limiting .
Peter