View source for 1017 User Guide

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<metadesc>Control 8 DPDT mechanical relays, switching up to 250VAC/2amp or 200VDC/2amp.</metadesc>
[[Category:UserGuide]]
==Getting Started==
{{UGIntro|1017}}
*[{{SERVER}}/products.php?product_id=1017 1017 Phidget InterfaceKit]
*USB cable and computer
*something to use with the 1017 (e.g. a power supply and load)


Next, you will need to connect the pieces:
[[Image:1017_1_Connecting_The_Hardware.jpg|500px|right|link=]]
# Connect the power supply and load in series.
# Connect the ends of the series to the NO (normally open) and the middle pin of one of the terminals.
# Connect the Phidget to your computer using the USB cable.
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{{UGIntroDone|1017}}

==Using the 1017==
{{UGcontrolpanel|1017}}

{{UGRelayOutputSignal|1017}}

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==Technical Details==

[[File:1017_1_Relay_Diagram.jpg|200px|right|link=]]

===Relays===
A relay is an electrically-controlled switch. Although many types of electrical switches exist, a relay’s mechanical nature gives it the advantage of reliability and current-switching capacity. The main disadvantage to using mechanical relays is their limited life-span, as opposed to solid state relays who do not suffer from this drawback. For more information, check the [[Mechanical Relay Guide]] and the [[Solid State Relay Guide]].

===Using a Digital Output Relay===
Relays have a connection scheme determined by the arrangement of contacts within the relay. Because relays are a type of switch, they are defined in the same way other electromechanical switches are defined.

In switch schemes, the number of poles represents the number of common terminals a switch has, and the number of throws represents the number of switchable terminals that exist for each pole. The relays used in the InterfaceKit 0/0/8 are DPDT relays: double pole, double throw. The internal construction of this type of relay is depicted in the diagram above. Many other types of relays exist:  SPST, DPDT, and DPST, to name a few.

In a relay, one of the throw terminals is labelled ''normally closed'' (NC), and the other is labelled ''normally open'' (NO).  As the name indicates, the normally closed terminal is the terminal connected to common when the relay coil is not powered. When the relay coil is energized by the relay control circuit, the electromagnetic field of the coil forces the switch element inside the relay to break its contact with the normally closed terminal and make contact with the normally open terminal. The switch element would then connect the normally open terminal and the common terminal.

===Rated Current/Voltage/Power===
These relays cannot be switched at maximum current and maximum voltage at the same time. Ensure that the total power of the load does not exceed the switching power of the relay. For example, you can switch these relays at 200V DC and 0.3 A (60W), or 30VDC and 2A (60W), but not 200VDC and 2A (400W). 

===Wetting Current===
When a relay is in one switch position for a period of time, oxidation of the open contact(s) can occur.  Depending upon the internal coating material of the contacts, oxide films of varying density will be displaced upon the surface of open contacts; this film acts as an insulator to current flow. When the relay is switched, a certain amount of current flowing through the contacts, known as the wetting current, is required to remove the film of oxides and ensure proper conduction. The wetting current required to operate this relay is low enough for use in signal switching applications. Check the specification table for your relay board to find out the Minimum Load Current or ''Wetting Current''.

===Load Noise===
If highly inductive loads are used with this InterfaceKit, it is recommended that a noise limiting component be used to prevent damage to the device.  An MOV, TVS diode, or kickback diode (for DC applications) shunted across the load will assist in dissipating voltage transients.

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