How (and why) to Ramble on your goat sideways
09-04-2012, 11:30 AM
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
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Yup.
When speaking of a power supply, consider the analogy of a water pipe in your home.
The pressure inside this pipe is regulated (by a device at the inlet to the home) to some constant pressure, say 40 PSI. Most of the devices in your home which use or consume water (the toilet, the sink, the water heater, the shower, etc) are designed to operate at this pressure. If you supply them with less pressure then the toilet will take longer to fill and your shower will produce a crappy spray pattern. If you subject them to significantly *more* pressure than this, they might fail catastrophically (toilet overflows, water softener bursts, etc.)
That's the "voltage" of the system- the amount of electrical pressure on the line. Volts = PSI.
Now, because the line coming into the home is only 1" in diameter, there's a limit to how much water the home can supply at once. If you've got the sink and the shower both on, you're drawing maybe 10 gallons per minute. If you then also flush the toilet, start a load of laundry and attempt to drown gophers in the lawn with the garden hose, these devices combined are now trying to draw 40 GPM, except that's more than the house can supply, so the pressure starts to drop and none of the devices work right.
That's the "rated supply current" of the system- the amount of electrical flow which it can deliver to all loads combined without falling below rated voltage or failing in some other way. Amps = gallons per minute.
There is no such thing as too much supply current. You could connect your little car stereo thing directly to the car's battery, which is capable of supplying upwards of 500 amps for short periods of time, and it would work just fine.
You must not connect any electrical device to a supply with a voltage which is higher than the device's rated voltage, however your MUST ALWAYS connect an electrical device to a supply whose source current rating is higher than the device's current requirement.
Assuming that you meet the voltage spec, the amount of current which any electrical device will consume is inherently self-limiting. For instance, a 100w headlamp, when connected to a 12v supply, will always draw 8.3 amps (google Ohms Law to see why this is). And your car stereo, likewise, will only draw as much current as it requires when connected to a 12v supply.
Note that for the purposes of this post, I am using "12 volts" to cover any supply voltage in the range of 11 - 14.5v which you'd normally encounter in a car. The math does move around a bit as the supply voltage goes up and down, but not enough to radically change the underlying principles being conveyed here.
When speaking of a power supply, consider the analogy of a water pipe in your home.
The pressure inside this pipe is regulated (by a device at the inlet to the home) to some constant pressure, say 40 PSI. Most of the devices in your home which use or consume water (the toilet, the sink, the water heater, the shower, etc) are designed to operate at this pressure. If you supply them with less pressure then the toilet will take longer to fill and your shower will produce a crappy spray pattern. If you subject them to significantly *more* pressure than this, they might fail catastrophically (toilet overflows, water softener bursts, etc.)
That's the "voltage" of the system- the amount of electrical pressure on the line. Volts = PSI.
Now, because the line coming into the home is only 1" in diameter, there's a limit to how much water the home can supply at once. If you've got the sink and the shower both on, you're drawing maybe 10 gallons per minute. If you then also flush the toilet, start a load of laundry and attempt to drown gophers in the lawn with the garden hose, these devices combined are now trying to draw 40 GPM, except that's more than the house can supply, so the pressure starts to drop and none of the devices work right.
That's the "rated supply current" of the system- the amount of electrical flow which it can deliver to all loads combined without falling below rated voltage or failing in some other way. Amps = gallons per minute.
There is no such thing as too much supply current. You could connect your little car stereo thing directly to the car's battery, which is capable of supplying upwards of 500 amps for short periods of time, and it would work just fine.
You must not connect any electrical device to a supply with a voltage which is higher than the device's rated voltage, however your MUST ALWAYS connect an electrical device to a supply whose source current rating is higher than the device's current requirement.
Assuming that you meet the voltage spec, the amount of current which any electrical device will consume is inherently self-limiting. For instance, a 100w headlamp, when connected to a 12v supply, will always draw 8.3 amps (google Ohms Law to see why this is). And your car stereo, likewise, will only draw as much current as it requires when connected to a 12v supply.
Note that for the purposes of this post, I am using "12 volts" to cover any supply voltage in the range of 11 - 14.5v which you'd normally encounter in a car. The math does move around a bit as the supply voltage goes up and down, but not enough to radically change the underlying principles being conveyed here.
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09-06-2012, 01:19 PM
why do my packages of parts and cool stuff deliver a day before or on I leave for something for the air force? This is the 6th time this has happened since the beginning of this year, i hate waiting just to get a package, let alone waiting extra days to see it because I just left.
Damn you UPS.
At least I get my two GTX 660ti's today, but my forged rods, pistons and other biddies come in tomorrow when I leave!
/rant
Damn you UPS.
At least I get my two GTX 660ti's today, but my forged rods, pistons and other biddies come in tomorrow when I leave!
/rant
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09-06-2012, 06:26 PM
Just bought this!
I'm tired of slamming my back against the floor after a long day. Time to try something a little easier.
I'm tired of slamming my back against the floor after a long day. Time to try something a little easier.
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09-07-2012, 09:48 AM
mkturbo.com
iTrader: (24)
Join Date: May 2006
Location: Charleston SC
Posts: 15,178
Total Cats: 1,681
Just bought this!
Back Magic Multi-Level Adjustable Back Stretching Device: Amazon.com: Sports & Outdoors
I'm tired of slamming my back against the floor after a long day. Time to try something a little easier.
Back Magic Multi-Level Adjustable Back Stretching Device: Amazon.com: Sports & Outdoors
I'm tired of slamming my back against the floor after a long day. Time to try something a little easier.
Reply
0
0
