Rate LED on Woodpecker

[Pauleo1214]

Does anyone know where to splice in the anode and cathode on the circuit to get a rate indicator led? Any help would be greatly appreciated!

Best,

Paul

 

[Cybercow]

Across R7 (in parallel with it). The cathode goes to Q2 (pin #1 of the 2N2646) and the anode goes to the other side of R7. R7 'might' need to be increased to 1K. Socket-n-see. Good luck.

 

[Pauleo1214]

Across R7 (in parallel with it). The cathode goes to Q2 (pin #1 of the 2N2646) and the anode goes to the other side of R7. R7 'might' need to be increased to 1K. Socket-n-see. Good luck.

Thank you Cybercow! Nice to see you on this board!

 

[Pauleo1214]

Thank you Cybercow! Nice to see you on this board!

Just a follow up, it does work. You did mean across R9 and Q3, right?

 

[Cybercow]

Just a follow up, it does work. You did mean across R9 and Q3, right?

I mean precisely R7 and Q2 according to the PedalPCB Woodpecker schematic. But it seems PedalPCB has changed up their BOM and schematic since I'd built mine. So here's a screenshot of the schematic I used in my older version where R7 and Q2 are referenced. . . . .

Note how the Rate LED has been added to the schematic. It will go in the same topological location on your build.

For the newer version, it would appear that rate LED would go across R6 with the cathode connected to pin #2 of the 2N6027. No need to modify the value of R6.

The Woodpecker can be built with either a PUT (2N6027) or a UJT (2N2646) - providing a couple other adjustments are made and the pinouts between the PUT and UJT are compensated for. The earlier version I have uses the 2N2646 UJT. And it appears that PedalPCB has changed up the schematic & BOM for using the easier to get 2N6027 PUT.

So, you can put a rate LED across R6 with the cathode connected to pin #2 of the 2N6027.

 

[Fishbonetabby]

To be clear for me to do this mod myself I would simply run a jumper from the LED anode to r6 and a jumper from the cathode to pin #2 of the 2n6027?

 

[Texasbluezman]

From what I've gathered, yes. This build is in my queue. I'm probably gonna do this mod also, but also add a SPST to turn off the blinking light. I would also like to add, it's probably better to use a diffused LED, as they're not as bright as those water color LEDs. I made that mistake on a Tremulus Lune clone. I had to change the resistor to dim the blinking LED. It would blind you! LOL

 

[Pauleo1214]

I mean precisely R7 and Q2 according to the PedalPCB Woodpecker schematic. But it seems PedalPCB has changed up their BOM and schematic since I'd built mine. So here's a screenshot of the schematic I used in my older version where R7 and Q2 are referenced. . . . .
View attachment 22800
Note how the Rate LED has been added to the schematic. It will go in the same topological location on your build.

For the newer version, it would appear that rate LED would go across R6 with the cathode connected to pin #2 of the 2N6027. No need to modify the value of R6.

The Woodpecker can be built with either a PUT (2N6027) or a UJT (2N2646) - providing a couple other adjustments are made and the pinouts between the PUT and UJT are compensated for. The earlier version I have uses the 2N2646 UJT. And it appears that PedalPCB has changed up the schematic & BOM for using the easier to get 2N6027 PUT.

So, you can put a rate LED across R6 with the cathode connected to pin #2 of the 2N6027.

Just wanted to circle back and confirm it works and thank you! I hate to be a PITA but I have a follow up question; the LED pulses at almost full brightness. Is there a value resistor you recommend between the anode and R6 that might exaggerate the pulsing effect?

B

 

[Feral Feline]

I think a resister as you described will just make the pulsing dimmer overall, it won’t aid in contrast in any way to exaggerate the rate.

I could be patently wrong, though, as I think I know more than I actually do.

Congrats on getting it to work — it’s on my todolist.

 

[Cybercow]

Just wanted to circle back and confirm it works and thank you! I hate to be a PITA but I have a follow up question; the LED pulses at almost full brightness. Is there a value resistor you recommend between the anode and R6 that might exaggerate the pulsing effect?

B

Yeah, adding a CLR in series with the Rate Indicator LED should do well to diminish the brightness.

 

[itstimtime]

Yeah, adding a CLR in series with the Rate Indicator LED should do well to diminish the brightness.

So I just added this in a combo build. It fired up and instantly heard (and smelled) the blown LED. I added a 2k2 CLR off R6 and the anode. The entire combo audio works, but any idea what to do/what I may have done wrong?

 

[Cybercow]

So I just added this in a combo build. It fired up and instantly heard (and smelled) the blown LED. I added a 2k2 CLR off R6 and the anode. The entire combo audio works, but any idea what to do/what I may have done wrong?

Dunno. Did you strap the LED in parallel with R6? Can't see what you did. Good, clear pic or two would help.

 

[itstimtime]

Dunno. Did you strap the LED in parallel with R6? Can't see what you did. Good, clear pic or two would help.

Honestly, in this context, I’m not too sure. I just ran a black wire off Q2 pin 2, red wire off R6 and attached the led black cathode, red anode and CLR

 

[Cybercow]

You should need only to strap the Rate LED across R6; with the cathode on the Q2 side.

 

[itstimtime]

You should need only to strap the Rate LED across R6; with the cathode on the Q2 side.

Hmmmm isnt that what I did? When you say across R6, are you saying attached to BOTH legs of R6?

 

[Cybercow]

Hmmmm isnt that what I did?

Not according to the pic you've posted.

When you say across R6, are you saying attached to BOTH legs of R6?

Yes. Precisely. Across both ends of (in parallel with) R6.

 

[itstimtime]

Yes. Precisely. Across both ends of (in parallel with) R6.

Thank you