You can, but it would be the world's biggest switch. What you're asking for is a _PST switch, for example a DPST (double) can control 2 independent circuits with a single throw of the switch, a TPST (triple) can control 3 circits, QPST (quadruple) can control 4... etc. Once you start getting above DPST the switches start getting pretty large. Why can't you do all the batteries and all the LEDs and all the fans on one switch?
"Help!" for: Electronics
- Thread starter 23Magnum
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thats what i am doing. i have two fans connected powered by two batteries which is operated by one switch...im just asking if thats a good idea? also is there any way to avoid my batteries becoming very hot besides unplugging them?
EDIT: the fans are 0.38A rated current, 4.56W power output and they are two 9V batteries...im not that great with wiring haha so not sure if thats smart...
EDIT: the fans are 0.38A rated current, 4.56W power output and they are two 9V batteries...im not that great with wiring haha so not sure if thats smart...
this is the best i can do with MS Paint (red= postive and black = negative obviously)
well money isnt much of a problem for me(i make a grand a week) but if AAs would work how many would i need to replace the 9vs?
Spartan 010
Jr Member
Typically, (Unless using Lithium Ion) AAs, AAAs, AAAAs, C, D, and button cell batteries, are 1.5 volts each. The bigger the battery, the longer they will last. However, the bigger the battery, of course, the heavy it will be.
1.5v X 2 = 3v
9v / 1.5v = 6 batteries.
If you place them in parallel (next to each other but not really "touching," they will remain 1.5v. If you place them in series(touching each other) they will gain 1.5v with each new battery.
9v batteries tend to run out of energy pretty fast. I would go with 6 (9v) AAs myself, but if space is limited, use AAAs, or button cells. Using button cells will give you a great amount of decreased time usage.
But if your fans need 12v, add a few batteries and throw in a Resistor http://en.wikipedia.org/wiki/Resistor of 100-1K on each fan for a "safety net" if you will. This should knock down the amperage a bit so you dont burn them out. I could be wrong though. You may want to wait for a more experienced member to answer your question in case I am incorrect in any part of my answer.
You don't want/need to knock down the voltage going to the fans, they want to take in 12V. Since each AA is 1.5V you'd want to wire 8 in series. This is easily done using 2 4 packs. 8 AAs will cost less than the 2 9V you're using, and they will last 3-5x longer. You can also use rechargeables (which is what I'll be doing in my helmet). You'll also be less likely to melt your fans than you will running on 9Vs.
so replace both 9vs for 2 four pack AAs?
Edit: lets say i have 7 LEDs wired to one 9v....is the resistor still necessary?
Spartan 010
Jr Member
I would definitely suggest resistors on the LEDS. If I have them, I put 1 on each LED. When LEDs take too much power / power for a long amount of time, they over heat and basically "burn out."
To achieve 12v you would need to place 8 AAs in series (+ - + - + - + -) You need 4 packs of 4 AAs. (4 x 4 = 16) If you can, you should buy the bundle pack or what not. You get like... 25 or 50 (I forgot) for $15-20
You actually dont really need to have 2 separate battery packs though. You should be able to use just 1 set of 8 batteries and hook both fans to the power source.
Depending on what kind of LEDs you use, so far as the voltage limit goes, you will probably need resistors. Most LEDs run about 1.4v-5v~. If you use 1 LED that has a volt limit of 5, but you use 6 volts, it will be slightly brighter for a time, however, it will most likely burn out. A resistor would protect any damage from occurring.
LEDs are kind of weird sometimes... You may not need a resistor at all. I have some LEDS that run on 2.2v with max of 5.5v. I can put 20 on 3v and they all light up as brightly as if I put them on different batteries, AND the batteries last for hours. Then I have another set of LEDS that run on 1.2v. If I put more than 1 led on 1 AA battery, the LED loses power and dims. 5 LEDs, no light at all. But if I use more power, they all light up correctly to the voltage I use.
I would suggest experimenting with them, carefully
thatdecade
Well-Known Member
Honestly, 12V fans are common but are the wrong type to be run on battery packs. A 3V or 5V fan will run just as well in a helmet without needing short lived 9Vs or heavy battery packs.
I generally wire LEDs with one 100 ohm resistors each on a 3xAA or 3xAAA battery pack with a 5V fan to a single SPST switch.
I generally wire LEDs with one 100 ohm resistors each on a 3xAA or 3xAAA battery pack with a 5V fan to a single SPST switch.
with my leds i have 2 3.2v, 2 3.7v and 3 (idk they where laying around in my electronic box) and they are wired in parallel with one resistor on a 9v and they all light up bright so i think things should be good. and i guess i need to order some 5v fans then right?
Edit....guys i dont think the AAs will work. i was popping in the batteries and one blew up and sprayed my eye.
EDIT 2.0. okay i tried powering each fan individually with 8 AAs and no explosions so maybe? haha thats two explosions and battery acid in my eye. i hate this suit lol
thatdecade
Well-Known Member
Oh wow, acid, ouch. What did you do to make that happen?
Those AA must have been smoking hot. What was the rating on your resistor?
Those AA must have been smoking hot. What was the rating on your resistor?
I didn't use a resistor. I figured 2 12v fan powered by 16 AA batteries would be fine. I mean it's 24 volts receiving 24 volts....so I had everything wired and as soon as I connected the battery packs and flipped the switch. POP...fizzle fizzle...Ughhhhhhhh!!!! Most painful thing I've ever felt and I've broken bones, tore my foot open, paper cuts. But for some dumb reason one fan powered by 8 AA batteries with no resistors is perfectly fine. I wired that while wearing my EOD helmet cuz of my lack of safety glasses and ili ran it for ~1.5 hours with no explosions or over heating.
MjolnirGraphics
New Member
Heads up to anyone trying to control multiple devices (lights, fans, etc) each with their own power requirements (voltage, amperage), there are three different methods that probably make sense: (Plus some pros and cons)
A. Power each device off it's own battery/power supply with it's own switch and everything
Pro - you can test and build each device independently
Pro - quick to troubleshoot
Pro - Each armor piece is separate from the others
Con - lots of batteries you need to keep charged
Con - Lots of switches that need to be turned on/off
B. Have one big battery/power supply with a bunch of different power regulators for each device
Pro - One switch
Pro - One battery to worry about
Con - One BIG battery to worry about
Con - Power regulators create a lot of heat
Con - Pretty complicated if you're not good with electronics
Con - Hard to troubleshoot
Con - All armor pieces need to be wired together (could be disconnected while not wearing it though)
C. Use relays to control the different devices from one switch (a relay works like a switch controlled by another switch. The control voltage and controlled voltage don't have to be the same)
Pro/Con - Depending on what relays you use, the suit might produce a loud click/crack noise when turned on
Pro - One switch
Pro/Con - Multiple power sources, but you could localize them all in the back or something
Con - All armor pieces need to be wired together (could be disconnected while not wearing it though)
A. Power each device off it's own battery/power supply with it's own switch and everything
Pro - you can test and build each device independently
Pro - quick to troubleshoot
Pro - Each armor piece is separate from the others
Con - lots of batteries you need to keep charged
Con - Lots of switches that need to be turned on/off
B. Have one big battery/power supply with a bunch of different power regulators for each device
Pro - One switch
Pro - One battery to worry about
Con - One BIG battery to worry about
Con - Power regulators create a lot of heat
Con - Pretty complicated if you're not good with electronics
Con - Hard to troubleshoot
Con - All armor pieces need to be wired together (could be disconnected while not wearing it though)
C. Use relays to control the different devices from one switch (a relay works like a switch controlled by another switch. The control voltage and controlled voltage don't have to be the same)
Pro/Con - Depending on what relays you use, the suit might produce a loud click/crack noise when turned on
Pro - One switch
Pro/Con - Multiple power sources, but you could localize them all in the back or something
Con - All armor pieces need to be wired together (could be disconnected while not wearing it though)
How did you wire everything when you did 16 batteries and 2 fans?
same way as that picture i posted only instead of 9v i used an 8 pack of AAs so there where 16 AAs. but for some reason when its just one fan and one 8 pack it works perfectly with no problems.
same here but two batteries from different packs?
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