Strand -10v signal current requirement

[Blaize110]

Ok. Thanks for that. I guess ill be building 6/7 inverters then.

[mutley]

OK, I've just finally finished designing the circuit and PCB for a 12 channel voltage inverter!! ;)

 

Literally, JUST finished tonight! I've etched the PCB, but not even drilled it, so can't test it yet!!!

 

I'm happy for people to use the PCB design themselves (but not to sell it or hire it out in any way), or you can IM me to arrange for me to make the PCB for you (at a nominal cost) :)

 

Full parts list (with CPC order codes) below.

 

It will actually invert in the opposite way as well! ie; If using a Strand analogue desk with a negative output, it will convert it to positive for use on "normal" dimmers. (powered either from dimmers or external power supply: 12-35v DC, centre positive - remove power source jumper!) :up:

 

To make the PCB yourself, you could try inverting the PCB image (flip it back-to-front), print it on a laser printer with heavy/dark toner setting, use a very hot iron to transfer the toner straight onto copper-clad board, then etch in Ferric Chloride.

 

Scale the PCB to exactly 94mm x 58mm to the outer border line.

 

Input side is the side with the DC power socket (the bottom as you look at the PCB layout in these pictures).

 

PCB layout: www.nwhoodz.pwp.blueyonder.co.uk/vinvpcb.gifhttp://www.nwhoodz.pwp.blueyonder.co.uk/vinvpcb.gif

 

Component layout (if you want to stick this to the component side of the PCB to make it easier): www.nwhoodz.pwp.blueyonder.co.uk/vinvlabl.gif

http://www.nwhoodz.pwp.blueyonder.co.uk/vinvlabl.gif

 

Component layout with pads (NOTE: 3 jumper wires required - shown):

http://www.nwhoodz.blueyonder.co.uk/vinvcomp.gif

http://www.nwhoodz.pwp.blueyonder.co.uk/vinvcomp.gif

 

Component list (with CPC order codes and prices not inc VAT):

 

• 1x Aluminium box, EN81244, £1.84
  
• 1x 2.5mm DC power socket, CN05839, £0.45
  
• 1x 555 Timer IC, SC04598, £0.21
  
• 3x LM324 Quad op-amp, SC07989, £0.22 each
  
• 1x 15v voltage regulator, SCL7815CV, £0.35 [soldered onto board with its metal tab to the DC socket, and body towards the capacitors)
  
• 3x 470uF 35v electrolytic capacitor, CA04759, £0.90 for a pack of 10
  
• 6x 0.1uF capacitor, CA05583, £0.35 for a pack of 5
  
• 1x 1nF capacitor, CA05508, £0.30 for a pack of 5
  
• 4x 1N4001 diode (or similar), SC07337, £0.40 for a pack of 10
  
• 4x PCB supports, PC00359, £3.25 for a pack of 20
  
• 1x 5mm LED (power indicator), SC07653, £0.50 for a pack of 5
  
• 1x 1k resistor, RE.25CF1K, £0.19 for a pack of 10
  
• 25x 10k resistor ±1%, RE03723, £0.45 for a pack of 50
  
• 1x 2k resistor, RE03739, £0.45 for a pack of 50
  
• 12x 100 ohm resistor, RE03791, £0.45 for a pack of 100
  
• 1x 3pin jumper strip (optional), CN00870, £0.59 for a strip of 40 pins
  
• 1x Pin jumper (optional), CN01411, £0.69 for a pack of 10
  
• 4x 8 pin DIN chassis mount sockets, AV05021, £1.72 for a pack of 5
  

The jumper pins are to select the following:

Short pins 1-2: power supplied by dimmer

Short pins 2-3: power supplied by desk (position shown in layout above)

Not connected: Use external power supply, desk/dimmer power not connected.

PLEASE NOTE: pin 7 (supply power) is NOT connected through from input to output. (If you are using this inverter, the chances are that the supply voltage from each unit will be the opposite polarity too! Not Good! :o ) Simply solder a wire between pin 7 on all the DIN sockets if you definately want this - check first!

 

8 pin DIN wiring: For pin numbering, please see this page (not associated with me):

http://freespace.virgin.net/tom.baldwin/pinout-8din.html

PULSAR USERS: If you are using Pulsar dimmers or control, you will need to change your wiring according to the pin layout shown by this link. (Either in the wires from the DIN socket to the PCB, or in an adapted control signal lead)

 

Anything else? Please IM me! ;)

[david.elsbury]

Wow! Impressive! Well done ;)

[mutley]

Prototype inverter circuit assembly continued here:

http://www.blue-room.org.uk/index.php?showtopic=31175