help identifying diode and specs

[AUS]

I have three of the modules you picture above but they're all for a 5.6mm diodes not 9mm. One of them has a screw you force the diode into the holder with do no press required. The others don't and yours probably won't have. They are aluminium and fairly soft and easy to press, but then I've never pressed a 9mm diode, the one I have here I bought in a module.

Pressing 5.6mm diodes can be easy or hard without a press. I've found a piece of pipe about 15mm long or a few nuts the right size works. It's not so bad if you have a vice. I've done it with multi-grips but it can be tricky. I've also had modules that are so loose the diode almost falls in and some so tight it has been almost impossible (mainly the chrome plated brass ones).

I would imagine the 9mm ones would be less fiddly but take more force.

 

[cyclonite]

Hi Aus,

Thanks for being with me through this.

I've received my drivers in the post today and so I hooked them up to an old stock of 1N4001 diodes with a 1/4 watt 1 ohm resistor.

By varying the dummy load I've found that it had an inverse effect on the current (doh!). i.e. the lower the dummy load, the higher the current that goes through the circuit for the same pot setting.

I've also found that even if I cranked the pot up to the maximum, it wouldn't supply more than 370mA with just a single 18650 battery (which had circa 4.0v). I had to stack 2 batteries in series to get the current to go up. Since my battery holder will only take 1 x 18650 battery, I'll stick 2 X CR123A batteries in there instead so I'll be able to supply the driver with circa 6.4v (assuming 3.2v per cell). I've adjusted the pot to give 1.01A at through the circuit at at 2.5v output.

The last bit is a bit of a problem. My 1N4001 diodes have a huge variance among them. All are a bit off 0.7v each. I'm unable to hit between 2.0v - 2.2v on the dot. So what I'm going to do is to tune down the pot so it puts out maybe 900mA at 2.5v. That way if the LD only has a load of 2.0v then the amperage shouldn't exceed 1200mA.

There's a slight design flaw with this driver in that the pot is on the same side as the power transistor so once I've epoxied a heatsink on, the value will be fixed for life.

Do let me know if you've spotted anything odd with my observations above.

Thanks.

 

[cyclonite]

An update, I've received an Email from the seller of the diode. Quote:

We've verified the laser driver you mentioned from the link you attached due its poor quality we do not recommend it to you.

However, we can suggest you another one from a different eBay seller (see link bellow).
You may see it simple but it will work Ok as an adjustable power supply.
LM2596 DC 7V-35V to DC 1.25V-30V StepDown Adjustable Power Supply Module LED td | eBay

I've checked it out and it looks great for the price. I'll probably order a couple to test.

 

[AUS]

Cool, and no worries on giving you a hand.
I forgot the linear regulator will drop the voltage by 1.125 volts too, that's probably why you needed two batteries in series (maybe). Putting them in series raises the voltage not the current, whereas putting them in parallel gives you more current but the same volts (although they need to be the same type and capacity or you can end up with one cell discharging into the other).

I'm away from home at the moment and on the iPad so taking me a while to respond.