We're try to get to 10 sets on the balanced input switch board.  Anybody else want to jump in?  We need 3 more

 

 

i will take a set of input boards please

42 minutes ago, kevin gilmore said:

i will take a set of input boards please

You're in...

I'm in too.

cool...  I can get the price down now I think

I found out that the switchboard needs a microprocessor (arduino etc) to control it.  same signaling as the original attenuator board.  The idea is no standing power on the relays.

Could someone familiar with this setup take a look at the board just to double check it?

soren wanted this, work in progress

 

can somebody who is familiar with this board take a look at it

http://gilmore.chem.northwestern.edu/boards/baseboardbal4.zip

It just needs to be checked so I can send it off to be quoted and close up the group buy.

soren also wanted buffers and a place for the attenuator on the board, which makes the board a fair bit bigger, and thus more expensive. if people think that is a good idea, or have other ideas i am certainly willing to modify. But i think that the smaller board is a better idea

Smaller board fits my needs better, but I would of course be fine with a bigger, more feature rich, version.

Would the buffers be installed vertically like on the ubal/bal board? I feel like it might be an issue with stacking one board over the other in that case. I am not likely to use it either because I'll already have the ubal/bal boards.

However I would use an interface for the digital attenuator. I am totally fine with the switch board as is but I wouldn't have an issue with extra features either.

I prefer a small board too

does it look ok to send to the board house?

 

25 minutes ago, sbelyo said:

does it look ok to send to the board house?

 

As far as I can tell; yes. Not an expert on how to set up the MAX4820 though.

I second Soren, all in one better than you second multi world

Is there a schematic and BOM for the recent group buy ubal/bal and diamond buffer boards?

here is the unbal/bal to bal board

 

diffinput3.PDF

Just making sure, the CCS LEDs need a 1.7Vf for all associated resistors (or vice versa)? 

does not really matter as long as they are matched

 

Drew up a little relay board for I/O since the one in the recent group buy one didn't quite fit what I wanted to do. Mainly it was that I needed to use I2C instead of SPI and I want to try stacking XLRs sideways to save space on the back panel. Any suggestions on how to improve it are appreciated. 0.3mm width traces

 

 

 

 

Looks good. My only suggestions would be:

1. fatten up the traces a bit
2. possibly flipping RN1 and swapping U1 with U2 might clean up the routing and number of vias. Or not.

 

U1 needs to be close to RN2 which is not really a resistor network, it's a DIP switch to change the I2C address but it uses the same footprint and I was lazy.  Will look into it anyway, thanks. 

Consider using jumpers (i.e. 2x3 header) instead of the DIP switch to set the I2C address?.

It should be a bit smaller and once you set the address I doubt it's going to change, so jumpers should be fine

//UFN

I looked into it and the relays and headers dictate the length of the board so I can't save anything there and it would probably only shave about 1-2mm off the width of the board, which probably isn't enough to do anything. Plus the DIP switch hearkens back to my horrible memories of grade school flip-flop truth table quizzes. 

A little breakout board for the AD5254 digital potentiometer... so I can dynamically bias the Dynalo through my phone (through a uC). 256 step resolution but lowest full wiper resistance seems to be 1k so 3.9 ohm per step.