55

4

4

3

3

2

2

1

1

D D

C C

B B

A A

General purpose input/output (GPIO) pins from the URI can sink only 8mA, not

enough for driving a relay coil directly. This circuit will boost the current up to

about 200mA to drive most small relays.

Set GPIO pin high to activate the relay, clear low to de-activate.

9080-24 -

URI GPIO Relay Connection

A

1 1Friday, October 29, 2010

Title

Size Document Number Rev

Date: Sheet of

GPIO

+12V

K1

RELAY SPDT

Q12N4401

R1

4.7K

D11N4001