diff --git a/Projects/RelayBoard/RelayBoard.txt b/Projects/RelayBoard/RelayBoard.txt index 1becfbb9f3..ce84c27eaf 100644 --- a/Projects/RelayBoard/RelayBoard.txt +++ b/Projects/RelayBoard/RelayBoard.txt @@ -50,8 +50,8 @@ * * Relays 1 to 4 are respectively wired to pins C4, C5, C6 and C7 of the Teensy++ V2, * which are the PORTC bits 4 to 7 of the AT90USB1286. The relays MUST be wired through - * a transistor, and a diode must be added on the relay's contact pins to protect - * the transistor from back EMF generated from the relay when the coil is turned off. + * a transistor, and a diode must be added in antiparallel on the relay's coil pins to + * protect the transistor from back EMF generated from the relay when the coil is turned off. * The transistor base pin is wired to the Teensy data port through a 10K resistor. A * LED may be also be added as a relay status indicator on each channel. *