la9
Well-Known Member
I hate to throw this in here but a car charger isn't a good substitute for a power supply, they are two different things.
Cant get this exaust fan going. NEED ELECTRICAL HELP!
- Thread starter wowzerz
- Start date
danksmoker77
Well-Known Member
you could always use two of the power supplies you have together. if 1 is 2.5A and one is3.5A then it will stay 12v but you will supply 6Amps
la9
Well-Known Member
What is the downside ? There is no load regulation for one, it is unfiltered DC for two., etc etc etc
It's people like you that start fires, I'm done with this thread, forget I was even in the conversation, I want nothing further with it......................
Wow, is it that time of the month again or what? Someone started ragging out of no where. LoL Whatever guy. I was just looking for advice. And if this is spmething that is a bad idea, I appritiate you letting me know. I only considered it because thats what I read somewhere else. I guess sometimes you just have to take things you read with a grain of salt. So anyhow...
Anyone else have any idea if this idea danksmoker77 said would work, using two power supplys wured together?
la9
Well-Known Member
Well it came off sounding a lot stronger than I meant it to be, just don't want to see anything bad happen to you. A battery charger is different from a power supply and it isn't a good idea to use one that way, even though you will here many people say otherwise. Without regulation that thing will continue to draw lots of amps if something bad happens which could very well lead to a fire, it's unfiltered so you aren't getting a steady DC voltage, it's just a bad idea.
keico
Well-Known Member
Don't get discouraged. I like yourself went through the same thing with my 12 volt fans
I just didn't have the money for those expensive fans. But in the long run 12 volt dc fans are better because they use less electricity.
Eventually you will find a system that works for you
I wish you the best of luck in your growing endeavor
I just didn't have the money for those expensive fans. But in the long run 12 volt dc fans are better because they use less electricity.
Eventually you will find a system that works for you
I wish you the best of luck in your growing endeavor
danksmoker77
Well-Known Member
wowerz you can wait for a second opinion but I am an electrical engineer went to college high everyday and all that. But anyway this will work just make sure you connect + to + to+ and - to - to -. Think of it kinda like jumper cables on a car battery. your r using the cars own battery (ac adapter #1), and the jumper cables (adapter #2). Your problem is when the fan tries to start there is an initial currrent draw that your adapter is not strong enough to handle. and dont be afraid of the electricity. This is relatively low DC current, it cant harm you.
P
Prot3us1
Guest
As long as you wire them in parallel they will work, if you try to wire them in series you will double the voltage.
Use your multimeter to find out which is positive on each transformer and connect them together. Then connect the fan to the leads.
http://www.4physics.com/phy_demo/batteries/BatteriesInParallel.html <<--thats in relation to batteries, but is simple, easy to understand, and has pics.
I would probably buy a surge/overload protector power board (shouldnt be expensive) and have both power packs plugged into it. Just remember, $25 for an overload protector (at the most!!!) but how much would it cost to rebuild your grow room from fire damage at the least, or your whole house at most.
The car battery charger is not a horrible idea, and you can get buffered and protected chargers...but they are usually the deluxe models..It will state overload protection on the box if yours has it.
Also, theres a thread on this forum thats all about turning a power supply for a computer into a 12v benchtop dc regulated supply. A higher gade PSU will have a higher rating, thats only a 100w one.
Think of voltage like your house water piping, and amps are like the pressure behind it...If you try to suck more amps through the wire than the voltage can provide the resistance in the wire will make it glow white hot, this only takes half a second and its a real danger! Id say either go with the 2x plug packs, or look into buying a better pc supply. PC supplies are great...VERY filtered, very stable, good protection...
If you still need any help let me know, send me a pm or ill subscribe here and see how you go. I always get myself into trouble trying to save money and do stuff myself lol...luckily I am studying electrotechnology at the moment..Ive not had a fire yet...well once on my motorbike when the shop didnt secure my battery properly and the positive post hit the frame i melted all the ground wires lol...but that wasnt my fault.
Use your multimeter to find out which is positive on each transformer and connect them together. Then connect the fan to the leads.
http://www.4physics.com/phy_demo/batteries/BatteriesInParallel.html <<--thats in relation to batteries, but is simple, easy to understand, and has pics.
I would probably buy a surge/overload protector power board (shouldnt be expensive) and have both power packs plugged into it. Just remember, $25 for an overload protector (at the most!!!) but how much would it cost to rebuild your grow room from fire damage at the least, or your whole house at most.
The car battery charger is not a horrible idea, and you can get buffered and protected chargers...but they are usually the deluxe models..It will state overload protection on the box if yours has it.
Also, theres a thread on this forum thats all about turning a power supply for a computer into a 12v benchtop dc regulated supply. A higher gade PSU will have a higher rating, thats only a 100w one.
Think of voltage like your house water piping, and amps are like the pressure behind it...If you try to suck more amps through the wire than the voltage can provide the resistance in the wire will make it glow white hot, this only takes half a second and its a real danger! Id say either go with the 2x plug packs, or look into buying a better pc supply. PC supplies are great...VERY filtered, very stable, good protection...
If you still need any help let me know, send me a pm or ill subscribe here and see how you go. I always get myself into trouble trying to save money and do stuff myself lol...luckily I am studying electrotechnology at the moment..Ive not had a fire yet...well once on my motorbike when the shop didnt secure my battery properly and the positive post hit the frame i melted all the ground wires lol...but that wasnt my fault.
la9
Well-Known Member
I wouldn't do it since both your DC adapters are different, you will have a case of voltage hunting that could cause one or both adapters to fail, or overheat.
If you want a big scientific explanation here you go.
To illustrate that case: you have a 12 volt DC car light bulb which is rated at 60 Watts so it takes a current of 5 Amps. You want to power-up the bulb from the mains using two AC to DC converters which each have a 12 volt DC output voltage but a rated output current of only 2.5 Amps each.
Wiring the DC outputs in parallel could work to allow double the current output of a single converter to be produced BUT ONLY IF THE TWO CONVERTERS WERE CAREFULLY WIRED with their DC + terminals (or wires) connected together and their DC - terminals (or wires) connected together. *** (See note below.)
However, whilst the resulting output voltage might be close to the output voltage of one of the converters, that cannot just be assumed! Particularly if the converters were not identical (if they were of different makes and/or power outputs, say) then the different slew rates of the convertors could cause the final output voltage to hunt around as the two converters tried to control each other. This voltage hunting would be accompanied (or caused by!) a current circulating between the two converters that was much higher than they were designed to handle. If they were badly matched such an unstable situation could lead to serious overheating and maybe a burnout of one of the convertors, if not both, even if there was no actual visible smoke and/or fire. (However this is not likely to be as bad as the situation described in the Note *** below.)
Such voltage hunting and higher than normal output current circulating between the converters (please note this does not involve the attached load - say a light bulb - at all!) might not be visible using normal test meters but, if present, would be seen on an oscilloscope.
To be safe - and to help avoid any overheating or burning-out of one or both of the converters - if you wished to try using them in parallel it would be very wise to wire a proper lab-type variometer into the AC mains feed and, whilst everything is switched off, attach your desired load to the parallel-connected outputs of the two AC to DC converters.
Then do this test: very slowly bring up the AC supply voltage from zero, measuring both the DC output current and voltage of each converter all the time. You should also watch and feel the adapters throughout the test to be able to detect any signs of overheating well before the full mains voltage is tried.
If you don't have the right kinds of controllers and instruments to measure what is really happening it would be best not even to try to do the above parallel-connecting "blind" at all. ("Blind" meaning "without instruments".) Instead the best plan would be to obtain a single AC to DC converter which has been designed to give the desired output current at the desired voltage. *** Note : IF THE CONVERTERS WERE WRONGLY WIRED with the DC + terminals (or wires) of one connected to the DC - terminals (or wires) of the other THERE WOULD BE A MASSIVE CURRENT CIRCULATING BETWEEN THE TWO CONVERTORS AND, IF FULL MAINS VOLTAGE WERE SUPPLIED, BURNOUT IS PRETTY MUCH GUARANTEED!
If you want a big scientific explanation here you go.
To illustrate that case: you have a 12 volt DC car light bulb which is rated at 60 Watts so it takes a current of 5 Amps. You want to power-up the bulb from the mains using two AC to DC converters which each have a 12 volt DC output voltage but a rated output current of only 2.5 Amps each.
Wiring the DC outputs in parallel could work to allow double the current output of a single converter to be produced BUT ONLY IF THE TWO CONVERTERS WERE CAREFULLY WIRED with their DC + terminals (or wires) connected together and their DC - terminals (or wires) connected together. *** (See note below.)
However, whilst the resulting output voltage might be close to the output voltage of one of the converters, that cannot just be assumed! Particularly if the converters were not identical (if they were of different makes and/or power outputs, say) then the different slew rates of the convertors could cause the final output voltage to hunt around as the two converters tried to control each other. This voltage hunting would be accompanied (or caused by!) a current circulating between the two converters that was much higher than they were designed to handle. If they were badly matched such an unstable situation could lead to serious overheating and maybe a burnout of one of the convertors, if not both, even if there was no actual visible smoke and/or fire. (However this is not likely to be as bad as the situation described in the Note *** below.)
Such voltage hunting and higher than normal output current circulating between the converters (please note this does not involve the attached load - say a light bulb - at all!) might not be visible using normal test meters but, if present, would be seen on an oscilloscope.
To be safe - and to help avoid any overheating or burning-out of one or both of the converters - if you wished to try using them in parallel it would be very wise to wire a proper lab-type variometer into the AC mains feed and, whilst everything is switched off, attach your desired load to the parallel-connected outputs of the two AC to DC converters.
Then do this test: very slowly bring up the AC supply voltage from zero, measuring both the DC output current and voltage of each converter all the time. You should also watch and feel the adapters throughout the test to be able to detect any signs of overheating well before the full mains voltage is tried.
If you don't have the right kinds of controllers and instruments to measure what is really happening it would be best not even to try to do the above parallel-connecting "blind" at all. ("Blind" meaning "without instruments".) Instead the best plan would be to obtain a single AC to DC converter which has been designed to give the desired output current at the desired voltage. *** Note : IF THE CONVERTERS WERE WRONGLY WIRED with the DC + terminals (or wires) of one connected to the DC - terminals (or wires) of the other THERE WOULD BE A MASSIVE CURRENT CIRCULATING BETWEEN THE TWO CONVERTORS AND, IF FULL MAINS VOLTAGE WERE SUPPLIED, BURNOUT IS PRETTY MUCH GUARANTEED!
P
Prot3us1
Guest
- We call it scavenging over here..good point. Id be more comfortable doing it if both of the adapters were rated higher than the fan could draw (to spread the load over 2).
Either way if its really drawing 3.5 amps, and you can get something putting out 5
you should be alright. The startup probly does spike at over 3.5A. Without knowing how much higher it goes its hard to say.
la9 obviously knows more than me, im still studying and learning...so ill leave the advice to him now lol, but whatever you go with in the end i would keep a close eye on it..if it seems the power pack is too hot unplug it...cooling it off isnt the issue, the heat means its bein stressed pretty hard which you dont want..
prot
danksmoker77
Well-Known Member
ok maybe we should consider what were asking you to do!! After thinking about having you wire to supplies in parallel and create any risks. here is an $11 no fail solution. APRONS AND GOGGLES SAFETY FIRST LETS GO OT LAB!!!
LOOSE WIRES CAUSE FIRES!!
hERES THE LINK:
http://cgi.ebay.com/AC-Adapter-Power-Supply-for-LCD-monitor-TV-Cord-12V-5A_W0QQitemZ260377413127QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item260377413127&_trksid=p3286.c0.m14&_trkparms=66:2|65:15|39:1|240:1307|301:1|293:1|294:50
LOOSE WIRES CAUSE FIRES!!
hERES THE LINK:
http://cgi.ebay.com/AC-Adapter-Power-Supply-for-LCD-monitor-TV-Cord-12V-5A_W0QQitemZ260377413127QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item260377413127&_trksid=p3286.c0.m14&_trkparms=66:2|65:15|39:1|240:1307|301:1|293:1|294:50
Here is the one I bought, same as that one 12v 5a, did not work, as stated before, did the same as last one, pulses on and off. This is the second LCD power supply I had bought for it, first one being 12v 3.7A
P
Prot3us1
Guest
You could always take the fan in to your local electronics retailer...no appliance retailer but electrical component retailr...over here we have tandy and dick smiths. Tell the staff you bought it on ebay, and need a supply for it...they should find a supply for you, and test it in store.
Alternatively ask the seller you bought it from what supply he recommends.
Alternatively ask the seller you bought it from what supply he recommends.
la9
Well-Known Member
Seller might not be able to recommend anything as it is for a boat and runs off a 12 volt battery with plenty of amps, so you don't really need a PS.
keico
Well-Known Member
This website tells you how to convert a computer power supply to a 12 volt dc power supply
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
la9
Well-Known Member
Hey la9, would you have any idea how to wire this fan off of either of these computer power supplys? I do have a multi meter BTW.
The 12 volt wire you need is yellow, you also need a ground which is black. Both supplies wil have the same color code so as long as you hook positive to yellow and ground to black you'll be alright.
Also need to know the power plug pins, the number of them, you may need to add a switch to turn the supply on or off, most motherboards take care of this operation with a transistor but you can add a switch, If it is a 20 pin on the antec then it's usually a green wire 4 pins over from the end and you connect the other side of your switch. If it's a different size let me know and I'll figure it out for you.
The LiteOn power supply looks like an old style with it's own switch already wired in, all you need to do is connect your fan red - POS AND black - NEG and you'll be all set.
Some people might say you need to add a load with a light bulb or resistor but as long as the fan stays connected you'll be fine.
f you have any other questions let me know.