Another electrical question from me...
07-10-2011, 07:20 PM
#21
JK Super Freak
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Attachment 180497..............
07-11-2011, 05:23 AM
#23
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http://en.wikipedia.org/wiki/Ohm%27s_law
Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points, and inversely proportional to the resistance between them.[1]
The mathematical equation that describes this relationship is:[2]
I = V/R
where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.
The mathematical equation that describes this relationship is:[2]
I = V/R
where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.
Last edited by Rednroll; 07-11-2011 at 05:28 AM.
07-11-2011, 04:19 PM
#24
JK Junkie
Back at ya.
http://en.wikipedia.org/wiki/Ohm%27s_law
Nice try though, but unfortunately still a fail.
http://en.wikipedia.org/wiki/Ohm%27s_law
Nice try though, but unfortunately still a fail.
Have a nice day!
07-11-2011, 08:39 PM
#25
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On a completely different note that switch you picked up is for VAC not VDC. Not sure how much DC power you are running through it but you could potentially overheat/melt the switch because its not rated to control a DC source at anything significant.
Joust my 0.02
CG
Joust my 0.02
CG
07-11-2011, 09:09 PM
#26
JK Super Freak
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even with a relay?
07-12-2011, 02:00 AM
#27
JK Junkie
You can use Ohm's Law ( E * I = P ) to do a baisc comparison of your switches.
E = Volts
I = Amps
P = Watts
So, the first switch ( 3A @ 125v ) means
125v * 3a = 375 Watts
So this switch is rated to cary a 375 Watt load on a 125 volt system.
Now the second switch ( 1A @ 250V )
250v * 1a = 250 Watts
So this switch will only carry a 250 watt load on a 250 volt system.
Now the last switch ( 5A @ 12V ). I will assume 12 volts since it is packaged with automotive equipment.
12v * 5a = 60 Watt
So now your next question will be: " How can I determine if I can use a different rated switch on my system"? The answer: Make sure that you use an equal or higher voltage rating "WITH" an equal or higher ampreage rating. Never use a lower rated switch.
P.S. You can use some basic Algebra on the above equation to rearange it to find the answer for many different wattage and amperage ratings.
E = Volts
I = Amps
P = Watts
So, the first switch ( 3A @ 125v ) means
125v * 3a = 375 Watts
So this switch is rated to cary a 375 Watt load on a 125 volt system.
Now the second switch ( 1A @ 250V )
250v * 1a = 250 Watts
So this switch will only carry a 250 watt load on a 250 volt system.
Now the last switch ( 5A @ 12V ). I will assume 12 volts since it is packaged with automotive equipment.
12v * 5a = 60 Watt
So now your next question will be: " How can I determine if I can use a different rated switch on my system"? The answer: Make sure that you use an equal or higher voltage rating "WITH" an equal or higher ampreage rating. Never use a lower rated switch.
P.S. You can use some basic Algebra on the above equation to rearange it to find the answer for many different wattage and amperage ratings.
125v is greater than 12v - So good to go there. And
375watt is greater than 1.2watt ( relay ) - So good to go there.
07-12-2011, 03:57 AM
#28
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Even with a relay yes it might be too much. For DC applications I bet the thing is rated at like 1A(or less)@5vdc. You should really find a DC switch with the proper rating.
125V is greater the 12V but its AC vs DC so you can't compare them. DC dissipate power constantly there for always generating heat and you can get thermal runaway or just a plain gooey mess. 125VDC@3A would probably turn this switch into a smoking pile and would easily put someone in the hospital (if not kill them) while 125VAC is about what most of us have in our house here in the US and will do little more than sting you. In-fact many electricians will put their fingers across 2 AC wires to tell the voltage but not on DC. AC is a sine wave and since everyone have most of the already this is the one I am going to pick
P = VI
In the case of DC V is constant (12V) and I will be pretty much constant over time and I will not change that much (on a switch through a relay)
in the case of AC (Assuming current is in phase with voltage) lets say 60 HZ AC twice a second V goes to 0 so P goes to 0 and you have no power running through the device there for it doesn't get stressed as much as with DC.
So AC ratings can't be use to know if something is "OK" in a DC system. Its apples to oranges. If you not careful you could fry you jeep or catch it on fire. You should know about the type of electricity and power you are playing and get parts specifically designed put the rating a type of electrical system you have.
CG
P = VI
In the case of DC V is constant (12V) and I will be pretty much constant over time and I will not change that much (on a switch through a relay)
in the case of AC (Assuming current is in phase with voltage) lets say 60 HZ AC twice a second V goes to 0 so P goes to 0 and you have no power running through the device there for it doesn't get stressed as much as with DC.
So AC ratings can't be use to know if something is "OK" in a DC system. Its apples to oranges. If you not careful you could fry you jeep or catch it on fire. You should know about the type of electricity and power you are playing and get parts specifically designed put the rating a type of electrical system you have.
CG
07-12-2011, 04:05 AM
#29
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Well...Then I guess Hella doesn't know what they are doing because the original switch packed is a VAC switch.
Everything is working great with the micro mini toggle switch. I've left it on for a while and it feels no warmer around the switch. Took it all apart and checked the backing...A OK.
Thank you again JK-Ford for keeping stuff fairly simple for me. My brain thanks you.
Everything is working great with the micro mini toggle switch. I've left it on for a while and it feels no warmer around the switch. Took it all apart and checked the backing...A OK.
Thank you again JK-Ford for keeping stuff fairly simple for me. My brain thanks you.
07-12-2011, 06:08 AM
#30
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I wouldn't go as far as saying they don't know what they are doing, they just probably know the DC characteristics of the switch they provided and just don't bother providing them to the end user. :P Regardless it sound like you are up and running and all is well.
CG
CG