I see a lot of questions about how to power a PC fan & a lot of misconceptions so here are some basics.
each fan will have a tag that states the voltage and current draw. transformers to power DC devices will also have a tag but it is a little more complex. it will state 2 voltages, the primary (or input) is usually 110-120 VAC in North America or 230 VAC for Europe, that is the voltage needed to power the transformer (aka xformer, wallwart, powersupply, ect). the secondary (or output) is stated as a voltage and an amperage (ie; 12vdc, 0.50amps). the stated amperage is the max the device can produce.other than laptops,most transformers are rated for 1 amp or less.be aware that some transformers output AC voltage instead of DC & you need the correct type of electricity to power your fan (some fans do require AC as well).
MOST PC fans are designed to run on 12VDC,( volts DC )they will work on voltages from 6- 24 vdc-the higher the voltage, the faster they will spin but overpowering(or underpowering) will shorten the life- its best to use as close a voltage as you can.
the second rating is the current they draw,it will be expressed in amps or milliamps(1000 miliamps = 1 amp) the power supply must produce at least as much amperage as the fan need. While a transformer will produce its stated voltage as soon as it is plugged in, it will only produce as much amperage as is demanded of it up to its rated limit. Using a 5000 miliamp powersupply to run 1 fan drawing 100 miliamps will not hurt! it is good because the transformer will not have to work as hard. I try to use a transformer rated for double(or more) the load I plan to use if the load is continuous. After running a fan for several hours, feel the transformer.if it is hot,it could lead to trouble -warm is normal.
most pc fans will have 3 wire,a red,a black & a yellow.the red & black are for power & the yellow is used to send a signal to a PC motherboard to tell it how fast the fan is spinning,just ignore the yellow.red goes to positive power,black to negative.if hooked up backwards,the fan will either not work or spin backwards. neither will hurt the fan or transformer. transformers usually have 2 wires,both black but 1 will have a stripe or ridge on it. the marked side is normally negative. just connect the red from the fan to 1 wire & the black to the other wire & plug it in,if the fan doesn't work switch wires. -when wiring a transformer,always unplug it. the voltage isn't enough to hurt you but if you touch the 2 wires together when powered,you will short a fuse and in most transformers,it cant be replaced.
when wiring 2 or more fans to the same transformer, you can do it 2 ways,either by wiring them in series or parallel.
parallel is the most common,just take you red wires and twist them together w/ your positive transformer wire & do the same w/ the black. the voltage going to each fan will be the same as the voltage of your transformer and you add up your amperage to find your draw. ie- 3 fans that draw .1 amp(100 miliamps) will draw .3 (300mil) from your transformer.
series wiring is where you take the positive wire from the transformer and tie it to 1 red fan wire.then take that fans black wire & tie it to the next fans red wire.the second fans black wire will go to the next fans red & its black will go to the transformer.doing it this way will give each fan only part of the voltage so if you have a 24 volt transformer & wire 3 fans in series,each will get 8 volts.2 fans would each get 12 volts.however the amperage will not change so if you have 3 fans that each draw .1 amp, the total load will be .1 amp.
series wiring is most common for speakers and is best to be avoided for fans but it is an option if you cant find a transformer in the range you need
each fan will have a tag that states the voltage and current draw. transformers to power DC devices will also have a tag but it is a little more complex. it will state 2 voltages, the primary (or input) is usually 110-120 VAC in North America or 230 VAC for Europe, that is the voltage needed to power the transformer (aka xformer, wallwart, powersupply, ect). the secondary (or output) is stated as a voltage and an amperage (ie; 12vdc, 0.50amps). the stated amperage is the max the device can produce.other than laptops,most transformers are rated for 1 amp or less.be aware that some transformers output AC voltage instead of DC & you need the correct type of electricity to power your fan (some fans do require AC as well).
MOST PC fans are designed to run on 12VDC,( volts DC )they will work on voltages from 6- 24 vdc-the higher the voltage, the faster they will spin but overpowering(or underpowering) will shorten the life- its best to use as close a voltage as you can.
the second rating is the current they draw,it will be expressed in amps or milliamps(1000 miliamps = 1 amp) the power supply must produce at least as much amperage as the fan need. While a transformer will produce its stated voltage as soon as it is plugged in, it will only produce as much amperage as is demanded of it up to its rated limit. Using a 5000 miliamp powersupply to run 1 fan drawing 100 miliamps will not hurt! it is good because the transformer will not have to work as hard. I try to use a transformer rated for double(or more) the load I plan to use if the load is continuous. After running a fan for several hours, feel the transformer.if it is hot,it could lead to trouble -warm is normal.
most pc fans will have 3 wire,a red,a black & a yellow.the red & black are for power & the yellow is used to send a signal to a PC motherboard to tell it how fast the fan is spinning,just ignore the yellow.red goes to positive power,black to negative.if hooked up backwards,the fan will either not work or spin backwards. neither will hurt the fan or transformer. transformers usually have 2 wires,both black but 1 will have a stripe or ridge on it. the marked side is normally negative. just connect the red from the fan to 1 wire & the black to the other wire & plug it in,if the fan doesn't work switch wires. -when wiring a transformer,always unplug it. the voltage isn't enough to hurt you but if you touch the 2 wires together when powered,you will short a fuse and in most transformers,it cant be replaced.
when wiring 2 or more fans to the same transformer, you can do it 2 ways,either by wiring them in series or parallel.
parallel is the most common,just take you red wires and twist them together w/ your positive transformer wire & do the same w/ the black. the voltage going to each fan will be the same as the voltage of your transformer and you add up your amperage to find your draw. ie- 3 fans that draw .1 amp(100 miliamps) will draw .3 (300mil) from your transformer.
series wiring is where you take the positive wire from the transformer and tie it to 1 red fan wire.then take that fans black wire & tie it to the next fans red wire.the second fans black wire will go to the next fans red & its black will go to the transformer.doing it this way will give each fan only part of the voltage so if you have a 24 volt transformer & wire 3 fans in series,each will get 8 volts.2 fans would each get 12 volts.however the amperage will not change so if you have 3 fans that each draw .1 amp, the total load will be .1 amp.
series wiring is most common for speakers and is best to be avoided for fans but it is an option if you cant find a transformer in the range you need