Steve Ward's Universal Driver 1.3: using IFD95 fibre optic receiver

[matt0852]

Hi again,

Has anyone successfully used IFD95T as the fibre optic receiver in Steve Ward's UD1.3? May I know the changes that need to be done to UD1.3?

Thanks!

[Mads Barnkob]

I used IDF95 in my http://kaizerpowerelectronics.dk/tesla-coils/kaizer-drsstc-i/

The difference is the polarity of the fibre optic receiver. You need to either leave out the IC1F pin 5 and out from pin 6 in the schematic: http://stevehv.4hv.org/newdriver08/DRSSTC_pndriver1_3b.pdf

Or you could use one more hex Schmitt trigger in series (IC1C is spare) with it to reverse polarity and still have the good clean square signal instead of just feeding the optic receiver straight into the AND gate, but I never had any problems by just leaving the IC1F out.

[matt0852]

I see. Do you have the pinout for IFD95? The pinout in the datasheet is rather unclear and I think I exposed it to reverse voltage first time round. Now it doesn't seem to be producing a voltage on my oscilloscope when I run a fibre optic signal into it.

[Mads Barnkob]

Looking at my first UD1.3 driver, I had the same trouble with the datasheet being a little unclear on the direction the pin out is seen from, as you can see here I ended up turning the opto 180 degrees.



I do not have the schematics accessable here at work, so we will have to do with this bottom side picture of the above driver



If you look into the opto, where you put the fibre cable in, you would have the negative leg in the left side and positive leg in the right side, signal in middle.

[matt0852]

Thanks! Could I see how you powered the IF-E96E fibre optic transmitter that you used in your interrupter in DRSSTC I? Can I just treat it as a regular LED and power it directly with a 100 ohm resistor using an arduino?

[Mads Barnkob]

Yes, you just drive it like a regular LED.

I would use 150 Ohm resistor for 5 V supply, since that would give you 20 mA forward current and a relative brightness of 1, according to the datasheet ( http://i-fiberoptics.com/pdf/if-e96edatasheet.pdf ) and you do not need it to be more powerful than that.

[matt0852]

Is there a difference between IF-D95OC and IF-D95T? I have a IF-D95T and so far I have been unable to get it to work even after following your instructions to integrate it into UD1.3. I can't even get any signal using my scope.

From what I can see, I'm guessing I should be getting IF-D95OC instead?  Apparently, IF-D95T has a "push-pull output" while IF-D95OC has a "open collector output". Since the UD1.3 had a 1K resistor between Vcc and the output, it kind of hints that the open-collector IF-D95OC should be used?

[matt0852]

Additionally, this is the fibre optic cable I'm using along with the IFD95T: https://www.digikey.sg/product-detail/en/broadcom-limited/HFBR-RNS005Z/516-2091-ND/1990489, and I have this weird feeling that this fibre optic cable isn't suitable. Could this be the reason instead as to why my receiver isn't working?

[Hydron]

Additionally, this is the fibre optic cable I'm using along with the IFD95T: https://www.digikey.sg/product-detail/en/broadcom-limited/HFBR-RNS005Z/516-2091-ND/1990489, and I have this weird feeling that this fibre optic cable isn't suitable. Could this be the reason instead as to why my receiver isn't working?

That fibre should be fine (I believe it's just standard 1mm plastic optical fibre). As for push-pull vs open collector, a 1k resistor will not hurt the push-pull version, but I would suggest making sure the polarity of output is the same - sometimes open collector outputs are active low where push-pull are active high. I've never used either of those receivers though, so others may have more definitive comments!