This board serves as a basic dual relay board
with 2 electromechanical relays.
• Fully optoisolated The card isolates
connections to protect your computer from short-circuit. An
opto-isolator is an integrated circuit that transmits the signal
through an encapsulated LED and phototransistor. When the signal is
on, the LED lights up, the phototransistor captures it and relays
the signal. In that way, your computer’s electronics are
completely isolated from the cnc circuitry. The signals are
transmitted through light and not through physical connections. In
this way, a power surge has no way of reaching your computer. That
is the reason why this card has two power connections. One power
connection is power powering the circuit that interacts with the
PC, the other connection is for powering the circuit that interacts
with your cnc system. Extra precautions have been taken when
designing this circuit, by taking into consideration the extremely
high voltages that stepper drivers can achieve and lack of
experience that some users could have in wiring circuits of this
• All TTL
+5VDC. Interface directly with parallel port interface
products and other cnc4pc.com cards. 5VDC (TTL) signals are very
common among automation devices.
• It can be
powered with +5vdc or a voltage between +7 and
• Works directly
with popular CNC hardware and software. . Such as
Geckodrive, DeskCNC or Rutex, and parallel port control software,
such as mach2, Linux EMC, TurboCNC, CNCPlayer, CNCZeus and others.
(Not all tested).
connections for all terminals. You only have to screw-on
the wires to make all your connections.
• Works as a set
of switches for powering your hardware. This board can be
used for turning on or off spindles, enabling contactors for large
spindles, coolant pumps, electro valves, etc.
• Controls 2
independent AC or DC devices.
The relays can take loads of up to 10 amps 28vdc or 125VAC
and 6 amps at 220VAC. Keep in mind that motors can draw up
to 3 times the rated current on start up.
Please note: This board requires buffered signals to
drive the optosiolatros, so it must be driven from a breakout
board, not the parallel port. If you need to drive the relays
without a breakout board, consider the C36
or the C37