Next Version of the SSRneon is here !

**budude** · 04-19-2012, 10:56 AM

My concern is more on the total current being sunk by the PIC since it seems like each output will be driving two separate paths of LEDs. But yeah, you would definitely need the larger transformer as well...

**gmbartlett** · 04-19-2012, 01:24 PM

Originally Posted by budude

My concern is more on the total current being sunk by the PIC since it seems like each output will be driving two separate paths of LEDs. But yeah, you would definitely need the larger transformer as well...

When I originally designed this I calculated the value of the current limiting resistor based on a red LED. If you plan to use a green or blue LED you may need to revisit the value of this resistor.

There isn't any issue with total current being sunk by the PIC because the new LED is in series with the opto LED so the total current draw is still about 5ma per channel. This is another reason I designed it with the red LED in mind. I'm not sure there is enough voltage to drive a blue LED and the opto LED.

So that being said you shouldn't need to use a larger transformer or worry about the current on the PIC because this design doesn't require any more current than the standard SSR design.

I've attached the schematic so you can verify my claim. If you have any questions about it please let me know.

**budude** · 04-19-2012, 02:11 PM

Originally Posted by gmbartlett

When I originally designed this I calculated the value of the current limiting resistor based on a red LED. If you plan to use a green or blue LED you may need to revisit the value of this resistor.

There isn't any issue with total current being sunk by the PIC because the new LED is in series with the opto LED so the total current draw is still about 5ma per channel. This is another reason I designed it with the red LED in mind. I'm not sure there is enough voltage to drive a blue LED and the opto LED.

So that being said you shouldn't need to use a larger transformer or worry about the current on the PIC because this design doesn't require any more current than the standard SSR design.

I've attached the schematic so you can verify my claim. If you have any questions about it please let me know.

To clarify - the reference was specifically for the Ren64 which has optional indicator lights. The combination of LEDs there AND the set on the SSR might put it close. If you are only pulling 5mA then it's probably OK - I don't recall what the LED power used on the Ren64 is but I think it's fairly low. Anyway - just wanted to be sure someone double checked!

**ukewarrior** · 04-19-2012, 02:26 PM

I have the wiki about 80% done.
I should only need a couple more days.

**P. Short** · 04-19-2012, 02:36 PM

gmbartlett: what Vf did you use when calculating the 220 Ω resistor?

My guess is that you were assuming 1.7V or 1.9V, although there are red LEDs with a much higher Vf. It seems to me that the LEDs need to be carefully specified, and that they will NOT be blue or white (they usually need a much higher Vf than can be supported by a PIC in series with the MOC).

**P. Short** · 04-19-2012, 02:40 PM

The indicator LEDs on the Ren64 are in parallel with the opto's, so the currents must be added together to determine the load on the PIC and the power supply. As I recall, the indicator LED current on that board was set for under 5mA. The indicators for the LEDs on the SSRneon are in series with the optos, so the same current flows through each, and thus the current drawn by this version fo the SSRneon should be roughly the same as the previous board.

**ukewarrior** · 04-19-2012, 03:07 PM

Thanks Phil !

Originally Posted by P. Short

The indicator LEDs on the Ren64 are in parallel with the opto's, so the currents must be added together to determine the load on the PIC and the power supply. As I recall, the indicator LED current on that board was set for under 5mA. The indicators for the LEDs on the SSRneon are in series with the optos, so the same current flows through each, and thus the current drawn by this version fo the SSRneon should be roughly the same as the previous board.

**tommy** · 05-07-2012, 12:27 AM

Nice looking design! I'm getting ready to make a bunch of SSR's for this year's display and would love to make some of these. Will there be a home etch version available in the wiki for those of us who want to roll our own?

Thanks for coming up with this design

Tom

**ukewarrior** · 05-07-2012, 08:35 AM

Hi Tom,

No, there is no home etch version for the G2-LED. The home etch version is the G2. Check out the wiki for more details.

Originally Posted by tommy

Nice looking design! I'm getting ready to make a bunch of SSR's for this year's display and would love to make some of these. Will there be a home etch version available in the wiki for those of us who want to roll our own?

Thanks for coming up with this design

Tom