OK, some I am finally going to wire this thing up but trying to figure out current limiting resistors for the LEDS. My guess is that originally there were four switchable functions and that at a later time Dumble added the fifth Jazz/Rock function. This would have been easy if he removed the 1K resistors on the power board and simply put a jumper. Then the appropriate series resistors could be added to the footswitch. Instead, he chose to parallel the four 1K resistors which is fine if only one LED is lit as it would add 250 ohm to whatever resistor I put in the footswitch. However, I have to assume that the device may be used with one up to five functions engaged at the same time which would have the effect of five times the 250 ohm or 1250 ohm (added to the value of each series resistor I have in the footswitch). I guess this would be easier if I had the device and simply tried different resistor values but I am working off pictures and phone calls. Any ideas?
CW
Favorite Enclosure for Four Button Footswitch?
Moderators: pompeiisneaks, Colossal
-
- Posts: 1104
- Joined: Thu Jan 23, 2014 7:32 pm
- Location: Laguna Niguel, California
- martin manning
- Posts: 13209
- Joined: Sun Jul 06, 2008 12:43 am
- Location: 39°06' N 84°30' W
Re: Favorite Enclosure for Four Button Footswitch?
Is there anything stopping you from adding a jumper over the paralleled resistors? It’d be much easier to get uniform brightness that way. Maybe that means someone on the other end would have to do that?
-
- Posts: 1104
- Joined: Thu Jan 23, 2014 7:32 pm
- Location: Laguna Niguel, California
Re: Favorite Enclosure for Four Button Footswitch?
Yes that would be the ideal way to do it but the customer seems to not want me to alter the device at all. He also doesn't mind if the LEDs dim a bit if all five are engaged. So I think the plan is to lite the LEDs with 20mA of current if one is engaged with a 265 ohm or so resistor plus the 250 ohm resistance on the power supply board. This should give me enough current if for some reason all five are engaged. Maybe a slightly larger resistor for the Blue LED( 20 mA 8.7 mcd 3.3v).martin manning wrote: ↑Wed Feb 21, 2018 7:41 pm Is there anything stopping you from adding a jumper over the paralleled resistors? It’d be much easier to get uniform brightness that way. Maybe that means someone on the other end would have to do that?
CW
-
- Posts: 1104
- Joined: Thu Jan 23, 2014 7:32 pm
- Location: Laguna Niguel, California
Re: Favorite Enclosure for Four Button Footswitch?
Well, here is what I came up with. Get to play through the preamp and some other Dumble amplifiers tomorrow.
CW
CW
You do not have the required permissions to view the files attached to this post.
Re: Favorite Enclosure for Four Button Footswitch?
Can’t wait to hear back!
Thanks,
Aaron
Thanks,
Aaron
-
- Posts: 1104
- Joined: Thu Jan 23, 2014 7:32 pm
- Location: Laguna Niguel, California
Re: Favorite Enclosure for Four Button Footswitch?
Well I had a good Dumble day today. Footswitch worked perfectly. All functions switched as they should and the LED brightness was perfect. My friend/customer was thrilled that I could figure it out from some pictures. Got to look at and hear some great Dumble amps also.
CW
CW
Re: Favorite Enclosure for Four Button Footswitch?
Great that it worked out. Was there any LED dimming issues, especially the switches with the shared power?
Thanks,
Aaron
Thanks,
Aaron
-
- Posts: 1104
- Joined: Thu Jan 23, 2014 7:32 pm
- Location: Laguna Niguel, California
Re: Favorite Enclosure for Four Button Footswitch?
Aaron, no dimming issues. I was surprised. My customer thought it was funny that I was being such a nerd about the LEDs.
CW
CW
- martin manning
- Posts: 13209
- Joined: Sun Jul 06, 2008 12:43 am
- Location: 39°06' N 84°30' W
Re: Favorite Enclosure for Four Button Footswitch?
Sort of a matter of professional pride, isn't it? Thanks for the interesting report!Charlie Wilson wrote: ↑Wed Mar 07, 2018 9:25 pm Aaron, no dimming issues. I was surprised. My customer thought it was funny that I was being such a nerd about the LEDs.