ilda electronics help needed please

[badger1666]

hi i am in need of a little help
i have an rgb projector running on a riya dac (the dac drives the colour channels differential +2.5v -2.5v)
what i also want to do is run my 2w445 mini projector on the same dac , so far i have just
run its diode drive from the intensity channel, the problem with that is it ttl,
is there a way i can run it analog and keep the projection whole ??
just putting it on one of the colour channels is no good only got part of the frame doing that need to find some way of mixing all three colour channels into one ?

any ideas wellcome

thanks

[stanwax]

easiest way is using diodes on the RGB inputs but you WILL loose a little signal
Rob

[badger1666]

easiest way is using diodes on the RGB inputs but you WILL loose a little signal
Rob

hi rob that what simon said to me untill i told him i got to diff drive the lasers
because the dac's + - 2.5v
can i still do it with diff drive ?
dont think 0.3v volt drop will be a big deal, would it ?
how would i place the diodes in a diff drive set up ?

thanks

[stanwax]

I did a mod to the 2 projectors Simon sold to Jem (which Richard now has) They were green with diff input and were driven from QM - works a treat
Just put a diode on each +input with the anode to ilda and tie the 3 cathodes together and place the other diodes in the -leg with the anodes tied and the cathodes to ilda

Rob

[badger1666]

cool thanks rob would these diode do the job ?
http://cgi.ebay.co.uk/Pack-6-x-BAT85...-/290422702406

[stanwax]

yeah should do the lower the forward volts the better
Rob

[mccarrot]

You should use low drop diodes like the BaT85, with this diode you will only 0,3V over the diode.

A standard 1N4148 will give 0,6V drop. 0,6V - 2,5V, this is 24% signal loss.

[stanwax]

Like the BAT85s he linked to.....

Rob