New line of laser diode drivers from 1A to 60A portable and stage ones

[0th3r]

Hello Guys,

Maybe some of you noticed me in the SELL section with my cylindrical optics. I'm here from 2010 but I was not posting much. I was learning and learning reading forums, news and even books
Together with friends we set up a laser company. Since I'm not well known brand yet, I would liek to make the review of my products myself. Since it is auto presentation I will try to be precise and show as much parameters as I can.
I'm open for all questions and critisizm, I can change and customize my projects. If you have any questions, feel free to ask. I'm able to provide any information - Trust me I'm engineer^^

I would like to start with my 5A micro driver.

It is designed to work with all diodes (<=5W), but because of the 5A capability it can work with 5W 808nm diodes or 3,5W 445nm ones.

This is linear driver with softstart and analog modulation and can be powered by 3,3 - 8V. Can not be used with 12V! It may be a slight obstacle but it is connected with the amplifier used in this project. Micro size didn't let me to use a voltage regulator.

For tests I was using: 5A Zhaoxin lab PSU, 2MHz signal generator 0-5V and Atten digital scope. Capacitor is needed since the long wirest from the lab psu made it oscillate. With capacitor all is working correctly. so driver should not be used without it. 220uF is minimum I think, but is provided with 470uF 10V one. I didn't add it on the PCB because THT capacitor can be mounted in different positions and help to save the space.


Driver's main parameters:

Input voltage 3 - 8 V
Output current - adjustable 0 - 5 A (one turn potentiometer)
Sense resitor - 3W 0,1ohm (for voltage drop calculations)
Softstart - 500 ms
Protection - 5V1 zener on TTL/Analog input
Board dimensions - 15,5 x 10,5 (mosfet size board)
Drills diameter - 0,8mm (dedicated for 0,34mm wires)


First the outlook:








Modulation scopes:




Softstart scopes:

Analog input was in high state during the main power switch on. After 500ms of course there is no delay between input and output signal.
You can see small bounces of the VCC input. It is caused by many effects. One - not very good PSU. Second - long cables between PSU and driver (around 1,2m).
Third - not very big input capacitor (330uF). But as it can be seen driver doesn't care with input fluctuations and the output is as it should be.




Load and frequency test:

9A load test at 100kHz modulation frequency shows how it works with bigger load and much bigger frequency (blue line was not connected):



I was also testing it at 12A with around 8V input but it is way too much for the sense resistor It is metal stripe 0,1 ohm 3W Bourns resistor so these are not 1W 2510 popular resistors.

Tell me what do you think about this project?
I will post more of my projects soon. I hope you will be interested in my 60A driver for high power infra red diodes

Hope to get your comments,
Mateusz

[danielbriggs]

Mateusz,
Great work - I might snag one to play with.

Just a question: are you (OptLasers) affiliated at all with the Chinese OptLaser?

Keep up the good work,
Dan

[0th3r]

Dear Dan,

thanks for your words!

No, I'm not connected with the Chinese OPT laser.
My brand name was created long time ago when I was not that much into lasers and I just didn't know about OPT Laser.
There are six people our the company and we are only in Poland for now on. I would like to tell the world about us.

The company name is "Tomorrow's System Sp. z o.o." in english it would be Tomorrow's System LTD and Opt Lasers is our brand.

[0th3r]

I would like to introduce my another two drivers. This one is much more advanced and is dedicated for laser projectors and RGB systems.

This one took much more time to fully test and make final version. There was I think four prototypes before final version.
During the tests I quickly found that that adding D-SUB connectors is not helping to achieve higher modulation frequencies. D-SUBs used in this project are rated at 5A / pin so it is hard to buy better D-SUB connectors.
Using my small drivers (for example from the first post) I can easily reach 200kHz just changing some capacitors.
This one has wider current paths, better elements arrangement, more space between paths... but the moment of adding D-SUB connector is spoiling the frequency graphs.
Hard to achieve nice and minimum round slopes. D-SUB connector won over the frequency so I lowered my expectations concerning >150kHz in below driver.

Taking into account the advice of the other forum member I created "lite" version of this driver without heatsink and without mounting holes as a cheaper version.
I also created three channel version, which can be easily changed into two channel version. It is the same circuit like the one channel version, nevertheless it doesn't have D-SUB connector.

Each version contains TEC controler with PID algorithm. Proportional parameter is most important and it is 8 times bigger than the intergrational one.
TEC is drivern by low frequency PWM which helps to obtain better efficiency of the Peltier module.

Features:

- 5A diode maximum current
- 1,5A maximumdiode bias current
- diode input voltage 5 - 16V
- reverse polarity protection for diode line
- modulation frequency 0 - 100kHz
- modulation voltage range 0 - 5V (Analog)
- 15A maximum TEC current
- TEC input voltage 3 - 16V (recommended to use >5V because this voltage is used to open the TEC N mosfet)
- 2 second soft-start (start delay for amplifier, not for power line, it works the same as the softstart in first post)
- PID algorithm which drive TEC using PWM
- 10k NTC thermistor as a temperature sensor
- temperature stabilization accuracy +-0,1*C
- LEDs for indicating TEC, NORMAL WORK, > 50*C ERROR
- D-SUB 25pin connector for 1 channel version
- appropriate heatsink applied

Only 5pcs of each have been produced to check market needs. I've already found that it would be nice to add some input connectors. When I'm using drivers which works with high power diodes I'm trying to solder wires directly to the PCB, especially the ones going to the diode. But I realized that anyway I should add at least input connectors in feaute versions. At the diode output it is possible to use 5mm terminal blocks.


One channel with D-SUB connector version:








Lite version:



Below you can see specific paths layout. It is made this way that D-SUB 15 pin can be used. So we can use D-SUB 25 or D-SUB 15 or just solder the wires.




Three channel vesion:





Just near the holes there are solder pads which are left free. It is made on purpuse to solder for example 3V3 transil diode or other protection devices.


If you have any questions feel free to ask. I'm sharing my small win, and maybe some of you will be interested in this kind of drivers.

[danielbriggs]

Mateusz,
These look very professionally fabricated.

A few questions:
- Is there any way to "tune" the PID response when the driver is connected to a thermal load?
- What is the voltage drop of the driver? i.e. If a connected laser diode has a forward voltage of 4.5V, what is the minimum voltage required to be applied to the driver for proper operation? (To keep heat dissipation to a minimum).
- Would there be any way of using these connectors for the TEC outputs? They do pins + housing for 10, 20, 30, 40A; I've used them before on high current loads. http://www.conec.com/en/d-sub-steckverbinder/
- What is the pitch spacing between the analog inputs pins, and diode output pins, should connectors want to be fitted?

Thanks,
Dan

[andy_con]

these look great, prices?

[0th3r]

Mateusz,
These look very professionally fabricated.

A few questions:
- Is there any way to "tune" the PID response when the driver is connected to a thermal load?
- What is the voltage drop of the driver? i.e. If a connected laser diode has a forward voltage of 4.5V, what is the minimum voltage required to be applied to the driver for proper operation? (To keep heat dissipation to a minimum).
- Would there be any way of using these connectors for the TEC outputs? They do pins + housing for 10, 20, 30, 40A; I've used them before on high current loads. http://www.conec.com/en/d-sub-steckverbinder/
- What is the pitch spacing between the analog inputs pins, and diode output pins, should connectors want to be fitted?

Thanks,
Dan

Dear Dan. Thanks again! I produced 10pcs of the one channel and 5pcs of three channel to improve everything in future versions.

Regardless of your questions:

1. In this version no. I was making lots of test and this PWM driver is workich such well that is almost do not need D and I parameters. I was doing many tests wit hdifferent values but result are explicit:
When we use quite high I parameter we got longet response but the temperature stabilisation is more accurate, even +-0,02*C but in laser projector the power is changing very spontaneously, and the system is too slow to react.
Proportional parameter is most important here it must react fast.
When we use derivatival D (I'm not sure about the word written properly) it is not helping.
In the current algorithm P=17, I=1, D=0.

2.
There is a 8A shottky diode with 550mV voltage drop to protect against reverse polarity.
The sense resistor is 0,1 ohm 3W 1%.
Problem is with the D-sub connector, it is 22mohm / pin but when we add male and female connector + cables it is creating much more resistance.
The mosfet is being opened with the voltage no more than 3,3V (because of the linear voltage regulator). I had to choose which regulator should be use 5V or 3,3V.
I decided to use 3,3V because in this situation, you can power the diode line with 5V and regulator will still be working correctly. Especially that I'm using this voltage for the bias current divider.
This means that mosfet is opened by high voltage (5 - 12V). The mosfet used are IRLZ44N it is not a secret. They are quite cheap and with low Vgs. We need around 0,5V.



So if Ud is diode operating voltage and I is desired current:
U = I * 0,1 + 0,6V + 0,5V + Ud + connector+cables resistance*I (I would choose 0,1 ohm or even 0,2)

For 4,5V diode operating voltage we will have:
I*0,2 +1,1V + 4,5V = 5,6V + I*0,2

3.
I'm not sure if I fully understand you. But:
I'm not using housing as a - connector. The number of pins I'm using is a bit too large, but I wanted to minimize the resistance of the TEC line espetially that it can use even 15A.
The connectors you send me are very nice but probalby they are also a bit expensive

4.
I must admit I made small mistake. The diode outputs distance in three channel driver is 4,5mm but you still can use 5mm raster connectors! I checked it
For the analog input raster is 2,5mm.
At start I didn't want to make any connectors and this is why I just forgot about this distance.

In future versions I will correct the pinout distances, for TEC too.

[0th3r]

these look great, prices?

Prices can be found on our website. But since these are new products all suggestions are taken under consideration.
http://optlasers.com/en/29-compact-drivers

[0th3r]

Hello Everyone.

I would like to show you a different driver. It is dedicated to work with high power (up to 60A) infra red laser diodes. Can power single diode or diode stack.

The heatsink is made of two parts. One inside is made of copper and is directly soldered to the power mosfet. It helps with fast energy transmission. Second part is alluminium body which is isolated from the copper part.
The current paths are made of 75um copper and are 15mm width, I would like to change them into 1mm copper flat in future improvals.

The main assumptions were: >50A current, compact build, and low voltage dropout. After first prototype I decided to stop at 60A and I managed to power 60W 808nm diode @60A with 3,3V PSU set to 3V only. So the heatsnk was just warm without additional cooling. Voltage drop on the driver is really low ~I * 0,015. Of course if we need to modulate the diode with sharper slopes a bit higher voltage is welcome for example 3,3V not 3V.

After 12V input there is 8V linear regulator and this voltage is used to power the logic part and to open the MOSFET. 8V on the MOSFET gate assures low Rds ON resistance - around 1,5 mohm.

It has 2 second softstart on modulation input (not on power line) I wanted to ensure that during switch on, modulation input is grounded. Shutdown pin is used to close the modulation input and does not switch off the main power line. After putting it to >3V it is indicating soft start again.

The modulation frequency is 5kHz but it is possible to make it even around 30kHz I wanted to ensure round rising slopes because the diode I have is CW one.


Parameters:

Maximum diode current: 60A
Maximum bias current: 20A
Laser diode suppply voltage: 2,5 - 24V read below!
Logic supply voltage: 12V
Modulation voltage ANG: 0 - 5V
Maximum modulation frequency ANG: 5 kHz
Connector material: copper
Power connector screws: stainless steel M5
Driver dimensions: 100mm x 50mm x 30mm
Inner heatsink material: copper plate
Outer heatsink material: alluminium
Isolated from all signals heatsink: YES
Mounting holes raster: 76mm x 40mm
Mounting hole diameter: 5,5mm
Transistor type: High power N-MOSFET
Maximum power dissipation: 200W
Current monitor: 10mV / 1A









What would you like to change, what do you like? Looking forward for your comments.

[0th3r]

Hello,

This time I have something a bit different. I don't want to create new thread as this one is not a laser diode driver. It is temperature controller. Since using Oclaro diodes is pain in the neck if we don't cool them I decided to make a project of good quality temperature controller. Price is not fixed so any resonable offers are taken under consideration (the same with all our products).

I was making many proportional TEC controllers but efficiency is not very good then. This is why I decided to make PID controller with PWM. PWM frequency is not high since all heating systems have long time response.
Using UART and Putty software you can read the PID parameters and temperature setpoint.

After small changes it can be adjusted to work with low voltage Peltier modules. In this version TEC input voltage is used also to open N mosfet, this is why it cannot be used with for example 2V TECs. But it is just a matter of one path.

If you have any questions please feel free to ask


Parameters:

Maximum TEC current: 8A
Supply voltage: 7,5 - 15 V
Radiator required: NO
Temperature sensor: 10k NTC B=3950
Temperature stabilization accuracy: +-0,1*C
TEC indicator: TEC LED diode
Power supply indicator: PWR LED diode
Connection with temp sensor loss: WARNING LED diode
Over 55 degrees Celsius: WARNING LED diode
Dimensions of the board: 47mm x 62mm
Heating mode: J1 soldered
Cooling mode: J1 unsoldered
0 - 50*C temperature range: J3 unsoldered, J2 unsoldered
0 - 20*C temperature range: J3 soldered, J2 unsoldered
15 - 35*C temperature range: J3 soldered, J2 soldered
30 - 50*C temperature range: J3 unsoldered, J2 soldered