Blue laser 74W NUBM35 Portabl?

[RedCowboy]

4.5V x 4.5A x 14 diodes = 283W + 5-10% for the drivers waste and the battery sag under load means about 12A from your pack @ 25V and as your cells discharge a little more, so as you have 2 x 18650's doubled up that's really about a 6A+ load per cell which they will do, you want to use good quality cells designed for high drain such as IMR or INR formulated so they don't sag excessively.

 

[Borislav@87]

4.5V x 4.5A x 14 diodes = 283W + 5-10% for the drivers waste and the battery sag under load means about 12A from your pack @ 25V and as your cells discharge a little more, so as you have 2 x 18650's doubled up that's really about a 6A+ load per cell which they will do, you want to use good quality cells designed for high drain such as IMR or INR formulated so they don't sag excessively.

I think it would be better to use two power supplies of 6 batteries each. As we commented, it will be best. Each pack of 6 batteries will power 1 driver and 7 diodes. I am wondering about the cooling fan, should I connect it to separately powered or should it be in one of the two power supplies.

 

[RedCowboy]

The fan doesn't draw much but if you have room then give it it's own battery, that way you don't need another dc to dc converter or a PWM speed control, just 3 cells in series and a switch.

 

[Borislav@87]

@RedCowboy
I bought 16AWG silicone cables today. I assume they will fit?

 

[RedCowboy]

That's more than sufficient.

 

[Borislav@87]

That's more than sufficient.

I also bought this 1800W converter which I plan to put in another project
1200W/1800W DC Converter Boost Automotive Power Module 20A 40A 20A Voltage Converter CV Boost Converter Voltage Regulator

https://a.aliexpress.com/_mtCSAIO

 

[RedCowboy]

Looks nice, the big caps are promising, I have some that I haven't tested yet, that said today's multi mode laser diode's are tougher than they used to be, but we still don't want a driver that produces start up spikes if someone switches on-off-on quickly, especially when we overdrive near the limit. I don't know enough to tell you by looking at it if it should be ok or not, but it probably will be.

 

[Borislav@87]

I will check for spikes before connecting the diode. I received these a few days ago and linked NUBM0E to them. Works great and no spikes on initial power up.

XL4015E1 5A DC-DC Buck Step-down Module Step-down Circuit DC To DC Voltage Step Up Down-converter Voltage And Current Regulator

https://a.aliexpress.com/_m06wm4K

 

[Borislav@87]

@RedCowboy

I have a question about battery power. I played around a bit the other day and wired up this box for 4pcs 18650 batteries. I didn't have a suitable cable at the moment and used a single wire hard cable, taking only the copper. I have connected everything in sequence as it should. I measured with a multimeter and the power output was about 15 volts. So far everything is ok. I wired up a 24V H7 truck bulb, wiring both the short and high beams together. After about a minute of operation, 1-2 of the batteries heat up too much. The question is, what is this due to?

That they are different batteries, that some are more discharged or I am confusing something. Brown ones are high discharge and green ones are normal.

Some of the things I've been waiting for have arrived. I'm waiting for the diode and batteries now.

 

[RedCowboy]

You want to use good quality cells, all the same brand/capacity cells, all fully charged and all the same age, new preferably for your high drain needs.

 

[Borislav@87]

I wanted to share some information that might be useful regarding this topic.
I manage to build a sexy looking version of NUBM35 portable laser inspired in the design of StyroPyro and with the HUGE help of Giannis_TDM. Big thanks to both of them!

You can see the end result here:

If you are interested in more information, you can download the FULL step by step instructions on how to make it yourself here:
https://truelasersaber.com - Just click of the "GET FREE" button and download the PDF.

The design features stable dual driver made of LM338s. One circuit for 5% power or 1.5W (positioning on target beam) and another 100% power or 70W. The drivers are controlled by momentary buttons that control the MOSFETs. There is also a general switch to turn on the device, as well as thermometer and voltmeter. All the power is supplied by 125C peak power Turnigy 4S+5S LiPo batteries connected in series. The charging is done by opening the lid and charging the LiPo batteries with regular LiPo charger.

The heatsink has 116 cm3 of aluminum which means that the temperature increase at a rate of 1.2 C for every second.
This equals to 10s on / 20s off duty cycle . If this duty cycle is respected the temperature is kept under 40 degrees C.

Runtime is also limited- between 3 and 5 minutes on max power (depending on how low you want to run the batteries - 3.5V vs 3.3V both under load.)
Of cause this is far from impressive, but IMO having a 70W sexy pocket BEAST with all the features you need (thermometer, voltmeter 5% and 100% modes, general switch, etc...) far exceeds the inconveniences. Finally, I built this almost an year ago and so far runs flawlessly after 35-40 charges.

I hope this information can help anyone that is trying to build something similar. Feel free to ask, if you have any question.

Alex

Ти от България ли си, защото адреса на сайта е български?

 

[TrueLaserSaber]

Здравей Борка. Да, от Русе съм, ама админа ми изтри поста. Каза че е "БС"

 

[Unown (WILD)]

Здравей Борка. Да, от Русе съм, ама админа ми изтри поста. Каза че е "БС"

Hello Borka. Yes, I'm from Ruse, but the admin deleted my post. Said it was "BS"

I'm warning you not to start arguments, thank you for your cooperation.

 

[Unown (WILD)]

Can you tell me how can I sponsor this wonderful page?

Please contact https://laserpointerforums.com/members/c0ldshadow.10634/

 

[Unown (WILD)]

You can also message him on discord with the link in my signature

 

[TrueLaserSaber]

I will do that too, just in case he does not read the direct message.
Thank you once again for your time, and apologize for the initial controversy.