12 th scale power supplies

RYY · September 30, 2005, 05:12:08 PM

While running indoors do most people still use a car battery to power up their chargers for their R/C battery packs??
RYY

jarrodH · September 30, 2005, 05:26:10 PM

you can use a car battery if you want, but a power supply is the easiest way for indoor, dave has one for sale in the buy sell trade forum

Grinder · September 30, 2005, 06:28:35 PM

Use an old computer power supply (cheap!). You may need to put a load the 5V side to get it to work (eg a power resistor, light bulbs, etc) because it's a switching power supply.

I finally found one that will run my charger even charging at 12 amps pulsed (8 continuous).

What rate do you charge at?

RYY · September 30, 2005, 07:10:26 PM

After the money I have had to invest in my 1/10 and 1/12 car I think I am going to stick with my car battery as it is quite small and portable. I just whated to get an idea of some other options in the event that I came across an unclaimed large amount of cash or found the last golden ticket.
RYY

September 30, 2005, 08:04:02 PM

i use the same power supply dave is selling.......... its small and can charge up to 10 amps....... and if i wanted i could use 2 chargers but still combined only 10 amps..........and much lighter than a car battery

Tom · September 30, 2005, 08:10:19 PM

...And easier to manage.
...And less likely to ruin your clothes.

As Grinder mentioned, solutions are available that are quiet cheap, however a really nice setup can be pricey, but worth it. Anything's better than dragging around a big Pb-Acid battery though, full of sulphuric acid, ready to eat your jeans. And, if you're going to be buying a new battery, you're a big chunk of the way to a power supply.

Mikemuncher · September 30, 2005, 08:15:31 PM

Hey Ryy,

Let me save you the hassle of lugging that huge ass battery around. I have spare power supply I can bring for you to borrow if you like. Let me know if this is help to you. :roll:

See ya at the track,

Mike

serpent · October 01, 2005, 02:37:43 PM

hey ryan there is usually lots of left over power .my power supply has 30 amps shane also has 30 amps so think about bringing long hook up leads for your charger and you will be ok with out your battery

Blake · October 01, 2005, 02:38:18 PM

Good call Mike, I'm sure there's lot of spare power floating around between us. I know that between Tom and myself alone we have about 120A of available 12V power. Plus, 40A of that is variable voltage between about 1.5V and 20V which is quite handy at times.

So, anyway Ryan (and others in a similar boat) , feel free to leave your car batteries at home and just tap into our power.

Blake

Blake · October 01, 2005, 02:40:37 PM

Ooops, Craig beat me to it!

Blake

SgRddY · October 02, 2005, 02:37:46 AM

i am using a 80A 14V power supply. this thing is insane, it will probably runs all the chargers that we all have... LOL...... it will also suppy 80A 28V at the same time. welding anyone?

cyrrus · October 02, 2005, 03:31:50 AM

Quote from: "SgRddY"i am using a 80A 14V power supply. this thing is insane, it will probably runs all the chargers that we all have... LOL...... it will also suppy 80A 28V at the same time. welding anyone?

/ \
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| All I can say is sick

Nasa Irocc has power :twisted:

Tom · October 02, 2005, 04:06:52 AM

Quote from: "SgRddY"i am using a 80A 14V power supply. this thing is insane, it will probably runs all the chargers that we all have... LOL...... it will also suppy 80A 28V at the same time. welding anyone?

Not on a standard wall plug it won't. Assuming 100% efficiency (which is impossible), that would be pulling 18 2/3 amps at 120 volt, which is over the standard 15 amp household circuit.

Either this is a 220 volt power supply, in which case it'll be difficult to find a wall outlet, or you're mistaken as to its capabilities.

I have a 12 - 14 volt adjustable 80 amp supply myself; assuming 100% efficiency at full load would be 9 2/3rds amps, well within the capabilities of a 15 amp 120 volt circuit. Assuming 80% efficiency (realistic for a switching supply), that's 12 amps out of the wall plug, or 1.4 kw (about what a hair dryer pulls).

However, this is extreme overkill for 1/12 scale racing. The best arrangement is to have a power supply that will go down to 8 or 10 volts, and 10 amps is more than enough current. Running your charger at 13.8 or even 12 volts charging a 4-cell pack can get it quite hot, especially when charging at 6 amps which is the norm with 3300's. Lowering the input voltage by dropping the output of the power supply, or even using a dropping resistor will help keep your charger cool. That's what's so nice about the linear supplies Blake and I have; we can run them with an output anywhere from around 2 volts up to 18 or 20 (depending on which one you use) at 20 amps. However, since they're linear, they're not as efficient as switching supplies, but that's a secondary consideration.

Grinder · October 02, 2005, 11:42:35 AM

It could probably supply 80A @ 14V (1120 Watts) though.... sounds like we have lots of power to leech off if we need to. The main problem is going to be everyone hooked up to the same terminal...

Tom · October 02, 2005, 12:57:15 PM

Yah; that's what I'm saying. That's equivelant to my Lamda power supply. The key is building a terminal block; something I haven't bothered doing.

However, like I was saying, it's best to run linear chargers for 4-cell packs (like the Hi-IQ) off of a lower input voltage so that they don't get quite as hot. A good rule of thumb is to use 2 volts per cell as an input voltage; a better one (I can't remember what it is off the top of my head) is to do something like 1.6 volts per cell, plus 2 volts, which amounts to pretty much the same thing 'till you get to transmitter packs.