HELP: ScanPro20 DMX Board!

[Things]

I just tried this, and it worked perfectly!

Just one thing, if you use it and notice the laser still abit dim, try putting a potentiometer across R5. I used a 10K pot, but any pot below that should be fine!

Just adjust the pot untill the laser is the brightest, and still has blanking. Go to far and you wont have blanking.

Mike - I'm not quite sure what your asking, but if you mean use a single transistor, then i assume it could be done.

I ended up using 2N2222A 's instead of the 2N3904 's, because jaycar didnt have them in stock. Still works perfectly!

[Hemlock Mike]

For simple switching like this, almost any NPN transistor will work.

I'm surprised at having to go below 1K for R5 to get sufficient drive.

Mike

[Hemlock Mike]

I was setting up my DX labbies tonight and noticed that they self bias ON. I have not tested yet but a simple inline diode may raise the TTL bias to 2.2 volts which may be enough to get the 0,1 logic levels.

Mike