eionmidi

Thanks Johnc Your diagram makes the circuit very clear. Eion.

Hi Jimhenry and Johnc Thank you for confirming my guess. The problem is that at the moment I have only one core so until a delivery comes from Smashtv, I cannot experiment. Johnc - the most immediate way I can see to run the SAMs is to use jOrgan. With its messaging it should do the trick. There is no pulse timing available, so the current sink stays on as long as you hold the combination piston. I am using original 1930s SAMs but they do have the advantage of switching off once they flip. This might cause other problems but it should reduce the current flow if you hold the piston for too long. Eion.

Hi I am intending using the DOUT boards with MIDIO128 cores to drive stop tab magnets on my organ console. Past posts have tended to refer to pipe magnets (which draw less current) and the R3 version of the DOUT. In this post http://www.midibox.org/forum/index.php/topic,6530.0.html Smashtv says: 'When loaded for relay drive the 2803's Vcc pin is brought out from each chip separately to it's respective output header. I figured the relay supply voltage would be near the devices to be driven rather than always near the DOUT itself. It's the one pin left unnamed on the J3-J6 connection silkscreen.' In the DOUT R4 board page there is a change: 'Isolated "spare" pads for driver chip loading to allow for easy use with alternate drivers' Q1a - Does this mean that for the current R4 boards, populated with ULN2803, neither the GND (pin 9) nor the Common (pin10) of the ULN is now connected to anything? Q1b - The Vs pins on each of the J3 to J6 connectors are connected to the ground of the board but NOT the GND of the ULN chip? Q2 - If so, what is the recommended method of physically wiring to these two pins? In my wiring design, the GND will sink 2 amps (the maximum is 4A). A clarification of these points will be helpful to the small band of organ enthusiasts. Any comments from forum members who are driving pipe or stop magnets with this board and ULNs would be very welcome. Eion.

Hi stryd_one Thanks for your reply. I have had a look at the link information. It may be that because my system is straightforward, that a very simple solution is possible. I will use say four cores as MIDIO 128 which will have only DOUTs connected to them to give me around 400 outputs to operate leds and magnets. Can I simply use the MIDI out to MIDI in connections? eg with two cores PC MIDI out -> Core1 MIDI in : Core1 MIDI out -> Core2 MIDI in In other words, does each core transmit incoming MIDI messages on to the next core from the MIDI out. There will be no possibility of feedback because I will not use the MIDI out of the last Core. Eion.

Hi I have had quite a long look at the previous posts but cannot find a definitive answer. I am midifying an organ console and will have around 150 SAMS and 128 lighted buttons. I will need four cores connected to DOUTs to drive the leds and DOUTs with ULN2803s to drive the magents. How do you physically connect up the cores so that the MIDI messages get through to the correct core. I have seen hints of daisy chaining and thru, but no one seems to have described it. I am using the kits from Smash TV Eion.