Stan_Ham diode driver (analog)

[megaton]

It seems to work...
I have one running at 12v and its outputting 1.3A and another running off 5.5v and it outputting 400ma.
But i cant seem to get the signal wire to work. i put it to 5v high and nothing happens.
I am using a different transistor.
MJE3055Tjp its rated to 4a the only difference is it has to be mounted backwards for the pins to line up.
but it should be working wish someone might be able to get on and answer a few questions tho.

I also change the transistor and work fine, try adjust the presets, Main for idle and idle for main.
But in your picture the transistor the base is in the emitter and the emitter is in the base.
I check the pins in the MJE3055T (you put it the same way like the other trans.)

[Elektrotechniker]

Hi

1-The red Led, I think is just for 20mA and there were suppose to be the Led Laser.
2- The 1 ohm resistor is in the green led (try that with 470 0hms).
3- The shunt resistor looks like a 10 ohms instead of 1.
All other parts looks fine.
Try to adjust first with a dummy load (4 diodes in series 1n4001 for red or 6 for blue)
I put 1N4007 and also work.
And put a voltmeter in the Monitor to adjust. (for 1mV = 1mA)for the 1 ohm shunt.
And the presets for me work Idle for Max current and Main for threshold or idle.
But I adjust it just perfect and work fine at the end.

I hope this help
Cheers,
Eduardo

BTW nice cutting.....

Heh thx for the compliment about cutting I first want to get this working then cut it properly. I don't have cutting tools anyway.

1- i just put that red led to test the driver( i will use a test load now )
2- what do you mean? The circuit in first post does not say I should place a 470 ohm resistor in parallel to the led( green led for me )
3- No, its an 1 ohm resistor.

[megaton]

Heh thx for the compliment about cutting I first want to get this working then cut it properly. I don't have cutting tools anyway.

1- i just put that red led to test the driver( i will use a test load now )
2- what do you mean? The circuit in first post does not say I should place a 470 ohm resistor in parallel to the led( green led for me )
3- No, its an 1 ohm resistor.

R16 is in series with the led (green for you)
R16 220 Ohms to 470 all depend your Volts. 220 for 6 Volts 470 for 12 V.
It said that you calculate that.
So shunt around 1 Ohm (R9)

[Elektrotechniker]

R16 is in series with the led (green for you)
R16 220 Ohms to 470 all depend your Volts. 220 for 6 Volts 470 for 12 V.
It said that you calculate that.
So shunt around 1 Ohm (R9)

Now i get it. thanks. My soldering station died, I will have to go and buy one tomorrow, so I can't make any changes to the circuit now. Last question, did I place the T1 BD437 the correct side or i need to place it the other way around ?

[kiyoukan]

i rotated it after i took the pictures of it.
It still does not seem to work and it looks like it fried my red loc laser... it outputs but not a beam and it gets hot quick. i dont see how 5.5v at 400ma should be perfect for this laser.
Will any npn transistor work?
I am going to try a different one in a bit.

[megaton]

Now i get it. thanks. My soldering station died, I will have to go and buy one tomorrow, so I can't make any changes to the circuit now. Last question, did I place the T1 BD437 the correct side or i need to place it the other way around ?

Yes T1 BD437 is correct

[megaton]

i rotated it after i took the pictures of it.
It still does not seem to work and it looks like it fried my red loc laser... it outputs but not a beam and it gets hot quick. i dont see how 5.5v at 400ma should be perfect for this laser.
Will any npn transistor work?
I am going to try a different one in a bit.

Yes you fry your loc. I use to run at that current but some locs cant handle it, but for long run between 360mA and 380mA is better (I run mine at 370mA).I fry some
And check for substitutes for the T1 (almost all npn work).
The 5.5 Volts mmm...
This is a current regulator and the laser just see no more than 3 volts (2.86 Volts in mine) But I use 6 Volts PSU. (just have to adjust the current if you use more)Less than 6V I never try.

[kiyoukan]

Okay i am having issues.
I dont get anything on my monitor port and nothing happens when i turn the pots.
the traces are all good but i get no response from the ports to check my current.

[Elektrotechniker]

Okay i am having issues.
I dont get anything on my monitor port and nothing happens when i turn the pots.
the traces are all good but i get no response from the ports to check my current.

check the bd transistor. Maybe you put it the wrong way.

[kiyoukan]

it is in the right way i turned them around after i took the picture.
The only things different are the transistor but i turned it around and it is in the right way now.
Would putting in the transistor the wrong way break the op amp?
And i use 1ohm smd resistors.
Other than those things everything is the exact same.
I have checked my traced and every one of them is solid and even checked with my multi meter.
this is so frustrating i build these drivers but in my infinite wisdom i still screw something up.