Recent content by SenorFrog

I think you may be right, hmm... This is an 89PR100 I found a data sheet here: 89PR100 - BI Technologies - datasheet If this is the case, what is happening? The resistance of the pot is going down? It has a minimum of 2 Ohms and at this setting the current should be 400 but is often 720, this...

Ive taken a photo of the complete circuit. Here it is: My camera is not the best, so Ive also drawn up a simple circuit diagram. The circuit is soldered onto stripboard, according to the included indication of connectivity. circuit diagram.jpg (I couldnt upload it here because of the images...

I also forgot to give you some information about the power source. It is a Ni-Cd rechargeable battery from an RC car, outputting about 7.5V. On the Laser drive site listed above it says that you could put 12V into the thing without worry, as the LM317 will dissipate whatever voltage it cannot...

Yes, the LM317 has a large heatsink bolted to it with thermal conductive gel, and the heatsink gets quite hot during operation.

I forgot to mention, once the test load reads 460mV, it stays there and doesnt fluctuate at all. The value only changes after ive removed the multimeter leads and found a stable value again. The same goes for the other value, when it reads around 700mV it doesnt seem to change at all unless I...

Ive built the DDL driver as specified at Laser driver - It can be done. I will be using it to drive an 808nm 300mW LD. Ive determined according to consensus on this forum that about 400mA is optimal for this diode, and I built the driver with 450mA as a maximum. Everything is functional and...

" Voltage needed by red LD 3v Voltage needed by regulator to make it work 3v Additional voltage to get long life between battery changes 1.2v. Add that up and you get 7.2volts " from: Laser driver - It can be done And since an infra red laser diode requires approximately 2V, I followed the...

Hi there, thank you for the welcome. I am planning on building the driver detailed here: Laser driver - It can be done Ive determined thus far that ill need 6.2 volts in total. 2.2V for the diode, 3V for the LM317 and 1.2V as recommended on the above page for longer battery life. Based on what...

Ive got everything I need to make the driving circuit for the 300mW infrared laser diode except the resistors, which I have yet to purchase. It seems to me that the 1 Ohm resistor in the test load will be subject to 2.2V and 400mA, which is what Ive calculated should be ideal for the 300mW IR...

Yes, just wood charring is what im after. After reading somebodies experience with a 300mW infrared diode, I bought two of those for a dollar each on ebay and will try my luck with them before spending anymore cash on a stronger diode. It seems he was quite successful with 300mW, although it may...

Hi again, I've answered my first and third questions already. I would still appreciate advice about the 2nd question if anyone is willing, and I have one further question about the drive circuit. Does the capacitance vary at all from diode to diode? Or will the 10uF 16V capacitor suffice for...

I am planning to start working with my first laser in an etch a sketch laser plotter I've been building, which is intended to burn wood and if everything goes well various other materials as well. I have a few questions I've been unable to answer on my own, I hope you can help! 1. Will the...