Powering an Intellicenter i5P

I wrote an earlier post about powering up the Intellitouch and Easytouch boards on my test bench, so I thought I'd add one about how I power up the Intellicenter...

To power these boards I use a bench/lab DC power supply because it lets me see and control the voltage and current supplied to the device.  The only significant difference with the Intellicenter is the voltage used... I use 12 volts DC (vdc) on the Easytouch/Intellitouch and 24vdc on the Intellicenter.

It's safe to connect a 24vdc source to the 18vac pins because the AC voltage at the input gets converted to 24vdc by the rectifiers/caps, and you can feed DC through a rectifier... I connect my leads using the polarity shown in the pic below, and if I use less than 21vdc, the the machine doesn't boot.  If you only have an 18vac source you don't need to worry about polarity.

The other two 24vac input pins can be left disconnected if you don't need the valves to work, or you can use any 24vac source you've got (I use a sprinkler system transformer)

One of the first things I do to an unknown board is power it up and check the current draw to get an idea of whether it's doing anything.  I have a variable DC power supply, so if the board is damaged it's a good idea to start with only a volt or two... that won't power the board of course but it'll make sure there's not a dead short.  If that checks out then I'd try 24vdc with a current limit of 300mA.

Note:  my board draws 60-120mA while booting**, about 105mA with the screen and backlight OFF, 70 with the screen on and backlight OFF, and around 62mA at idle with the screen totally off.

**The boot sequence draws about 60mA until the screen turns on, then it goes up to 100-120 and then once booted settles back down to 100 until the backlight shuts off, at which point it goes to 70-ish until the screen totally turns off.  This will vary depending on backlight brightness etc.

Update:  You can power the main/lower board while it is disconnected from the top board.  If you assume J3 uses zig-zag numbering, i.e. the row with pin1 is all odd and the row above is even (pin 2 is above pin 1), you can power the lower board by connecting 24vdc to J3 pin 4, and GND to J3 pin 32, see J3 diagram - I used asterisks to represent the pins:

   24v                                       GND 
 2 (4) 6  8 10 12 14 16 18 20 22 24 26 28 30(32)
 *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
[*] *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
 1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31