Supplying Power To The Controller - 3M SC400 Reference Manual

12

Supplying Power to the Controller

You must supply the SC400 controller with power. The source must deliver (for 5 VDC)
16 mA typical, 27 mA touching; ± 5% regulation or (for 12 VDC) 19 mA typical, 30 mA
touching; ± 5% regulation, with a maximum ripple and noise of 50 mV peak-to-peak.
You can supply power to the SC400 controller using any of the following methods. The
voltage input can be either +5VDC or +12VDC. In Sleep Mode the controller draws less
than 5 mA.
CAUTION
To avoid possible damage to the controller, you must provide a path for electrostatic
discharge (ESD). The controller mounting hole near the touch screen connector should be used
to connect to chassis safety ground and must be attached by the shortest possible route to a
good earth return (chassis) in all applications.
Note: To avoid possible damage to one or both of the power supplies, do not supply both
internal power and external power to the controller. Power from two sources could cause damage.
Using an Internal Power Supply to JP4
Provide power directly to the controller using JP4 (Molex 22-05-3031). Use a mating 3-
pin connector (Molex 22-0 and Pins 08-50-011X) and connect Pin 1 to 5VDC power and
Pin 2 to the return or (alternately) 12VDC to Pin 3 and Pin 2 to the return.
Using an Internal Power Supply with a Custom Serial Cable Design
When creating a custom serial cable connection, you can provide power to the controller
through the mating Molex connector. Refer to Table 1 for more information on actual
cable connections. Unlike using JP4 of the controller to supply power, you can only use
5VDC at the serial interface.
1. Obtain an 8-pin Molex connector 51004-0800.
2. Attach power and ground to the connector, (Pin 6: +5V, Pin 7: Ground).
Using an External Wall-Mount Power Supply
If you are using a standard 3M Touch Systems RS-232 serial cable (P/N 7319630), you
can use a 120-volt wall-mount power supply (P/N 19-408). Typically, this option is
utilized by developers for prototyping purposes only.
To connect an external wall-mount power supply:
1. Remove the plastic plug covering the power jack of the 9-pin D connector on the serial cable.
2. Connect the DC power plug to the power jack built into the 9-pin D connector. Note that
power is applied to the shield and ground to the center pin.
3. Plug the power supply into a grounded outlet. The power plug supplies +5V and return to the
controller.
3M Touch Systems Proprietary Information
SC400 Controller Reference Guide