PHR-805t Build Questions?

[furrylaser]

Hi. I've never made a laser before and I really want to start. I have purchased a PHR-805t diode, a groove v2 driver, an aixiz module, a lab heatsink, and a 9v battery. I have a few questions,
Has anyone used the groove V2 driver and is it reliable?
Can i use a 9v battery or do i need a different battery?
And fyi I want to power the diode at around 100mW.




Thank you

 

[Isoleucine]

Oh wow, I shoulda written up a super thorough build guide. Anyways...
I have the exact same build as you do.

Yes! I have one of these things, a 9V battery will work, although it's capacity is really, REALLY bad. It will not keep your diode running very long. But for a beginner's build, it'll get you by in a pinch.

As far as the groove goes, drlava did a fairly nice job with this thing. Do note that you MUST know how to measure and set current. It will work, but remember the dropout voltage. Anyways, use a test or dummy load as a ... basically a dummy. For a PHR use 6 1N4001 (4001-4007) rectifier diodes, and hook up a 1ohm resistor at the end. This will emulate/simulate the diode's load when in operation. Power the driver up with the battery. Use a multimeter and measure the millivoltage across the 1ohm resistor to get your current in milliamps. This is so because of ohms law:

I =V/R
WHERE I is current in amps, V is voltage and R is resistance. Since R is 1, we just get current, but in mV form.
This will cost no more than 3$ for the rectifier diodes.
The diodes may get hot-ish, since energy is lost in the rectification as heat.
The current you want to set it to to balance diode life and diode power is around 120mA to 130mA. Do not go above.

The groove v2 is relatively reliable. As long as you're not powering anything outrageous, you should be fine. I have the same build as you, and it works FINE.

The lab heatsink you have... is not really needed unless you are going to run your diode for more than 20 seconds. The diode will get warm and hot if heatsinked improperly. Typically used for the 445 diodes here on LPF. They get hotter tenfold.

Hope it works, don't forget to check out soldering guides, I can help with that too.

Iso

 

[piferal]

^ I have a question,

if your diode is an PHR-805t, and this usually running at ~5.5V approx.

And you use a 9V battery with a linear driver with an Dropout Voltage of 1.2V,
this gives a ~7.8V approx. in the output of the driver.

Ie about ~2.3V more than expected for this diode.

There is something that escapes me here?

Maybe the Dropout Voltage of this driver is more than 1.2V of what is stated in the specifications?

 

[Isoleucine]

It'll work. I think he's following the styropyro build with a 9V battery. I've checked on HTD and many other sites, and it shows quite a similar pattern... although it has a terrible capacity, it is commonly used, and even I use it and its fine. The dropout voltage doesn't really matter in most cases, even if the voltage is higher than the diode... its not that bad really. AS long as the current doesnt go overboard, he should be perfectly fine.

 

[furrylaser]

which battery would u recommend for best life and performance?

Would two 18650 3.7v batteries work well?
I have a lot of those for some flashlights i have.

 

[Isoleucine]

Well, since a 9V battery works, you can use two 18650's. They will most likely work, with such a huge capacity, you can keep it running for hours. If you can find a HOST (housing, typically a flashlight that has been gutted out and cleaned of stock components and ready to install your diode), you can put a laser in a flashlight. I prefer 18650's since they are nicely sized and have a large capacity. 14500's ... 10440's even AA's if you have enough.

But usually a Li-Ion battery works best as you can recharge. If you only want to use a single battery, use a boosting driver, which automatically boosts the voltage to meet the appropriate needed voltage. They're a tad expensive, but they are suitable for high current use, if you're gonna reuse drivers. But for now, stick to two 18650's or a single 9V battery and you can go lase as much as you want. Building a flashlight laser requires some degree of research on wiring, but its not that hard.

DIY: How to Make a High Powered Burning Blue/Violet Laser Pointer - YouTube

Your build is easily and clearly demonstrated here. However, a previous version of the diode, the 803T not 805T is used, and it comes from a laser sled housing. You can use two 18650's the driver and diode will be able to operate with no problem. Except for maybe some heat... but its no big deal if you have a short duty cycle. Used to prevent overheating of the diode.

duty cycle: time on = time off.
30 seconds on, then 30 seconds off...

Edit. If you use extra voltage, the largest chip on the drive board... the LM117 or 317, can't remember probs 117, will get warm. Excess voltage will be dissipated as heat. If you are using a high voltage source, BE CAREFUL and heatsink your thing.

 

[jost4318]

so would the driver just output the correct voltage for the diode?
sorry for the noob question still learning

 

[Isoleucine]

In short yes. It'll just dissipate the extra voltage as heat in the driver and the diode. The closer the voltage to the operating range of the diode, the less heat will be generated. Since you're using a Groove 2 or some other linear current regulator, you may want to consider using a voltage that is ideally 5.7 volts, but 6 volts should be the best. The reason you do this is because the driver will cut off the extra voltage and leave you with a nice voltage that will work with the diode. The dropout of the groove is 1.2V, and the operating voltage of the PHR is 4.5V last time I checked. The dropout voltage is the amount of voltage that the driver will cut off in order for it to regulate the current properly. So you will need to provide it with 'extra headroom' and use 6V as a voltage source. Keep in mind that 6V is ideal because the dropout voltage may vary from unit to unit so keep some leeway for it to operate, and as a tradeoff, you generate a slight amount of heat.

Iso