Using jayrob's build but im having a problem

[chaosfourever]

it it also read 0.65v before I put on the test load also.

 

[jayrob]

Yeah... I know you said you checked everything, but either something is not built correctly, or possibly, components got 'fried' from when you connected improperly.

Have you studied this diagram from DDL's thread?

Everything is the same, except you are not using the pot, and you are replacing the 10 ohm resistor. (3 ohm = 420mA's)
Jay

 

[chaosfourever]

Im using that one,but also im using the 2 10ohm resistors because im doing this build for the 16x burner. Im just using the mxdl like yours. I just have no clue because it was at 5V and now when I put the 1n4001 the correct way it is at 0.65V. much harder then I thought this would be.

 

[jayrob]

It's actually very easy when it is spread out like the diagram (picture). It's when you try to compact it onto a small round board like the MXDL circuit...

I always use my DMM to test continuity... (open or closed) connections between the different components to make sure that everything is connected correctly. Test from the circuit board as well.
Jay

 

[chaosfourever]

I'll look again. I just don't wanna do it again because this is my second time completely building the driver. Though I did impliment your electrical tape idea on the board and it helped to keep the circetry a little cleaner.

 

[daguin]

I'll look again. I just don't wanna do it again because this is my second time completely building the driver. Though I did impliment your electrical tape idea on the board and it helped to keep the circetry a little cleaner.

How many rebuilds is it worth to you to have a laser that you built yourself?  Are you paying by the hour somewhere to use the equipment?  This is a HOBBY.  That means you spend time on it.  If it takes 15 rebuilds, it will still be done and made by you.  Your next one will be easier.  The one after that even easier.  Take the time needed (how ever much that is) to LEARN.  If you just want a laser today, buy one from somebody else who took the time to learn.  Of course you're going to be paying at least three times as much for it AND you cannot say you did it yourself, but hey . . .you've got it now.

Peace,
dave

 

[chaosfourever]

Wow ok so I have a major update. I Tried some more to fix my second driver. I finally decided to start again now. I tested directly at the silicon chip and im actually reading 7.6v. I bought rechargable ones that said each was 3V, but apparently they lied so yes I have 7.6V and that would help to explain a few of my problems. OK so jayrob using your build still what must I get for resistors and such to counter act this 7.6V so that I will get the correct 3V needed?

 

[chaosfourever]

also I am still building this for the Sony 16x diode.

 

[jayrob]

It's kind of strange the way it works with measuring these DDL drivers. But it is very important that you test for current.

* When testing voltage, without a load, you will see very close to the same as your input voltage. Once you connect your test load, you will measure the test load voltage (at the test load) The LD will take what ever voltage it needs, as long as the supply voltage is at least 3 volts more than the voltage that the LD needs.

For a red diode/DDL driver, you will want to use 2 X 3.6 volt rechargeable batteries. (not 3.0)

For a blu-ray diode/DDL driver, your supply voltage will be better at 9 volts.

* Current: This is the main thing you will want to confirm with your test load. It is important to have a proper test load in order to get an accurate reading for the current.

If you are going for 420mA's, then a 3 ohm resistor is what you will want. (this is a good place to be for a long open can - heatsinked)

2 X 10 ohm resistors in parallel, will give you 250mA's. (this is the same as a 5 ohm resistor)

A Sony/Senkat diode is good at around 250mA's to 300mA's. If you use a 4.3 ohm resistor, you will get about 294mA's. This is what I like for those diodes. (heatsinked) That will put you right around 200mW's through an AixiZ acrylic lens.

The formula is: Voltage divided by ohms = current. (the voltage is always 1.25 - this is the regulated voltage between the pins at the LM317) Example:

1.25 / 5 ohms = 250
1.25 / 3 ohms = 416
1.25 / 4.3 ohms = 290

Jay

 

[chaosfourever]

ok, but like i said I took off the entire driver and tested directly at the chip. This was 7.6v with the 2 3v rechargables so by doing this I should try to compensate for the extra voltage correct? How will I get rid of the extra 0.4v?

 

[jayrob]

If you carefully read my last post, it should answer the questions that you keep asking about voltage... Final voltage is determined by the LOAD. You must have a proper test load. CURRENT is what you need to check...
Jay

 

[chaosfourever]

okey, cool I finally got it. After using the test load it started at like 3.5V initially, but in like a second or two it was able to stay at about 3.2V. So now I just gotta build it like normal again right?

 

[jayrob]

I may be able to help you more, but I would need to see pictures of your entire set up. Including battery supply, DMM connections, and everything...
Jay

 

[chaosfourever]

ok ill get to work this week and update here later. thx again for the extra help

 

[chaosfourever]

ok so I just built a new driver again and it is my best one yet. With the test load attached I hold steady at 2.43v. So now what? Will it be perfect without the testload attached or what's my next move?

 

[jayrob]

ok so I just built a new driver again and it is my best one yet. With the test load attached I hold steady at 2.43v. So now what? Will it be perfect without the testload attached or what's my next move?

If you have a proper test load, you are just checking the current. This will tell you if your driver/battery configuration is correct.

Once you have done this, remove the batteries, short the two leads together to discharge the cap, and then you are ready to connect your LD.
Jay