relay?

2lw4fthos · 06-28-2005, 02:28 AM

ok this might need to be in the electrical forum but here she goes
why do i need a relay on my compressor
can someone please explain to me why i would need one
i mean cant i just use a fuse?
or am i missing the whole point of what a realy does
please help me out and explain this to me in a way i can understand

vio0633 · 06-28-2005, 06:45 AM

A relay acts like a switch. When 12vdc is applied from your PS when the psi is low to the relay it will click over and turn the compressors on.

Ozwald · 06-28-2005, 09:57 AM

Just wanted to add that you could burn up you PS if you run the power for the compressor thru the switch. I'm not using an inline fuse, I'm using a 30a relay as the 'fuse.'

-Kevin

98SS · 06-28-2005, 11:15 AM

Maybe this will help.

->Click Here<-
(In case the page will not load, the information is copied below.)

A relay is a simple electromechanical switch made up of an electromagnet and a set of contacts. Relays are found hidden in all sorts of devices.
A relay consists of two separate and completely independent circuits. The first is at the bottom and drives the electromagnet. In this circuit, a switch is controlling power to the electromagnet.
When the switch is on, the electromagnet is on, and it attracts the armature. The armature is acting as a switch in the second circuit. When the electromagnet is energized, the armature completes the second circuit and the light is on.

When the electromagnet is not energized, the spring pulls the armature away and the circuit is not complete. In that case, the light is dark.

When you purchase relays, you generally have control over several variables:

The voltage and current that is needed to activate the armature
The maximum voltage and current that can run through the armature and the armature contacts
The number of armatures (generally one or two)
The number of contacts for the armature (generally one or two -- the relay shown here has two, one of which is unused)
Whether the contact (if only one contact is provided) is normally open (NO) or normally closed (NC)

In general, the point of a relay is to use a small amount of power in the electromagnet -- coming, say, from a small dashboard switch or a low-power electronic circuit -- to move an armature that is able to switch a much larger amount of power. For example, you might want the electromagnet to energize using 5 volts and 50 milliamps (250 milliwatts), while the armature can support 120V AC at 2 amps (240 watts). Relays are quite common in home appliances where there is an electronic control turning on something like a motor or a light. They are also common in cars, where the 12V supply voltage means that just about everything needs a large amount of current. In later model cars, manufacturers have started combining relay panels into the fuse box to make maintenance easier.

In places where a large amount of power needs to be switched, relays are often cascaded. In this case, a small relay switches the power needed to drive a much larger relay, and that second relay switches the power to drive the load.

~~Phildo~~ · 06-28-2005, 11:28 AM

that needs added to the basic baggin FAQ or something!!

very nice tim!

2lw4fthos · 06-28-2005, 01:02 PM

ok but i am not running a PS im just running a manual switch you still think i need one?

~~Phildo~~ · 06-28-2005, 01:05 PM

yes. just put the manual switch in place of the pressure switch

98SS · 06-28-2005, 01:34 PM

Quote: Originally Posted by y2k xtreme

yes. just put the manual switch in place of the pressure switch

He just said he wasn't running a PS.

Do you mean put the pressure switch in place of the manual?

~~Phildo~~ · 06-28-2005, 01:37 PM

Quote: Originally Posted by 98SS

He just said he wasn't running a PS.

Do you mean put the pressure switch in place of the manual?

no, i was referring to a typical setup. instead of using the PS, run those wires to a manual switch.

06-28-2005, 02:28 AM	#1
2lw4fthos Beau is low Age: 22 Join Date: Nov 2004 Posts: 1,538 Location: orange park,florida User is: OffLine	relay? ok this might need to be in the electrical forum but here she goes why do i need a relay on my compressor can someone please explain to me why i would need one i mean cant i just use a fuse? or am i missing the whole point of what a realy does please help me out and explain this to me in a way i can understand
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06-28-2005, 06:45 AM	#2
vio0633 SIC FL Chapter prez Age: 29 Join Date: Jan 2004 Posts: 3,330 Location: Pensacola, Florida User is: OffLine	Re: relay? A relay acts like a switch. When 12vdc is applied from your PS when the psi is low to the relay it will click over and turn the compressors on.
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06-28-2005, 09:57 AM	#3
Ozwald I got nothing... Age: 29 Join Date: Nov 2003 Posts: 398 Location: Glen Burnie, MD User is: OffLine	Re: relay? Just wanted to add that you could burn up you PS if you run the power for the compressor thru the switch. I'm not using an inline fuse, I'm using a 30a relay as the 'fuse.' -Kevin
	[Reply w/Quote]

06-28-2005, 11:15 AM	#4
98SS former owner Age: 26 Join Date: Feb 2003 Posts: 7,314 Location: Memphis 'burbs User is: OffLine	Re: relay? Maybe this will help. ->Click Here<- (In case the page will not load, the information is copied below.) A relay is a simple electromechanical switch made up of an electromagnet and a set of contacts. Relays are found hidden in all sorts of devices. A relay consists of two separate and completely independent circuits. The first is at the bottom and drives the electromagnet. In this circuit, a switch is controlling power to the electromagnet. When the switch is on, the electromagnet is on, and it attracts the armature. The armature is acting as a switch in the second circuit. When the electromagnet is energized, the armature completes the second circuit and the light is on. When the electromagnet is not energized, the spring pulls the armature away and the circuit is not complete. In that case, the light is dark. When you purchase relays, you generally have control over several variables: The voltage and current that is needed to activate the armature The maximum voltage and current that can run through the armature and the armature contacts The number of armatures (generally one or two) The number of contacts for the armature (generally one or two -- the relay shown here has two, one of which is unused) Whether the contact (if only one contact is provided) is normally open (NO) or normally closed (NC) In general, the point of a relay is to use a small amount of power in the electromagnet -- coming, say, from a small dashboard switch or a low-power electronic circuit -- to move an armature that is able to switch a much larger amount of power. For example, you might want the electromagnet to energize using 5 volts and 50 milliamps (250 milliwatts), while the armature can support 120V AC at 2 amps (240 watts). Relays are quite common in home appliances where there is an electronic control turning on something like a motor or a light. They are also common in cars, where the 12V supply voltage means that just about everything needs a large amount of current. In later model cars, manufacturers have started combining relay panels into the fuse box to make maintenance easier. In places where a large amount of power needs to be switched, relays are often cascaded. In this case, a small relay switches the power needed to drive a much larger relay, and that second relay switches the power to drive the load.
	[Reply w/Quote]

06-28-2005, 11:28 AM	#5
~~Phildo~~ Dildoans Age: 28 Join Date: Jun 2001 Posts: 18,121 Location: Ft. Wayne, IN User is: OffLine	Re: relay? that needs added to the basic baggin FAQ or something!! very nice tim!
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06-28-2005, 01:02 PM	#6
2lw4fthos Beau is low Age: 22 Join Date: Nov 2004 Posts: 1,538 Location: orange park,florida User is: OffLine	Re: relay? ok but i am not running a PS im just running a manual switch you still think i need one?
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06-28-2005, 01:05 PM	#7
~~Phildo~~ Dildoans Age: 28 Join Date: Jun 2001 Posts: 18,121 Location: Ft. Wayne, IN User is: OffLine	Re: relay? yes. just put the manual switch in place of the pressure switch
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06-28-2005, 01:34 PM	#8
98SS former owner Age: 26 Join Date: Feb 2003 Posts: 7,314 Location: Memphis 'burbs User is: OffLine	Re: relay? Quote: Originally Posted by y2k xtreme yes. just put the manual switch in place of the pressure switch He just said he wasn't running a PS. Do you mean put the pressure switch in place of the manual?
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06-28-2005, 01:37 PM	#9
~~Phildo~~ Dildoans Age: 28 Join Date: Jun 2001 Posts: 18,121 Location: Ft. Wayne, IN User is: OffLine	Re: relay? Quote: Originally Posted by 98SS He just said he wasn't running a PS. Do you mean put the pressure switch in place of the manual? no, i was referring to a typical setup. instead of using the PS, run those wires to a manual switch.
	[Reply w/Quote]