Max Current on Rhino

NETMF & Gadgeteer
1

Hi all,

How many current I can pass through :

  • Digital Output
  • Analog Output
  • Pin 48 (3.3V)
  • Pin 50 (5.5V)

Thx
Hervé

2

Nobody know that ?

2mA / 8mA or what else ?

3

4ma is a safe measure.

As for the 3.3 and 5V lines, look at the datasheets of the voltage regulators used on the boards.

4

Thx very much.

5

Make sure you are not powering high power (>~15ma) circuits directly from fez.
Make sure you have some side circuitry which is controlled with fez via either relay or transistor.

Powering high power circuits directly from fez will most likely fry your chip.

6

Let me rephrase that: via either a transistor or a relay controlled by a transistor.

Most relays draw to much current to be powered by a FEZ pin.

7

I used a couple transistors driven off of a fez pin to drive a string of LED’s to use PWM dimming. The need of the transistors because I was using constant current sources to drive 20ma of current through the LED string. That is a level the Panda would not have appreciated.

Worked pretty good and was documented here for those unfamiliar with using transistors off a pin:
[url]GHI Electronics – Where Hardware Meets Software

8

[quote]Let me rephrase that: via either a transistor or a relay controlled by a transistor.

Most relays draw to much current to be powered by a FEZ pin.[/quote]

Correct ;D