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Valen
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solenoid driver chips are usually ~$1 or so
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Post Mon Oct 20, 2008 9:57 am 
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dyrodium
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Free is cheaper. Wink But cheers for the imput Jake, it might be handy down the track. Smile
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Post Mon Oct 20, 2008 12:06 pm 
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cavecrusher



Joined: 14 Jul 2006
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Location: Netherlands


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small question for a non-battle purpose

Is it possible for an IBC to drive a mini-MAG, each output driving a single set of brushes and plugged into the same channel?

Post Tue Oct 28, 2008 2:52 am 
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Spockie-Tech
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Insufficient Information, but off the top of my head - not likely.

You need to take into account - intended operating voltage, likely peak stall currents at that voltage, AND what sort of sustained load is to be driven and likely sustained current at that load for what duty cycle / duration.

according to this.. http://www.robotcombat.com/products/magmotors_info.html
The s28-150 (I asssume this is the "mini" mag ?) is rated for 3hp, or 2.2Kw. at 24volts - thats around 91 amps, assuming 100% efficiency.. - so more likely 120+ amps at rated power.. with surges likely to be double that..

The IBC will cope with around 20-30 amps per channel sustained (with airflow), 50 amps intermittently, and *brief* bursts of 80-100 amps if given plenty of time to cool off between high peaks..

So if you intend to run your mag at anything like its rated power for any length of time, its probably going to want too many amps for the IBC.

Robot Combat reccomends *dual* Victors (120amps each, 240 amps combined) to run one properly at high power.
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Post Tue Oct 28, 2008 9:25 am 
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shreddy



Joined: 09 Jan 2009
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Location: Wantirna, Melbourne


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anyone know anything about toy rc systems?
mine seems to have crapped out but the reciever/esc shows the on light when it is switched on.
ill get pics soon
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Post Thu Jun 04, 2009 5:38 pm 
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Glen
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question,

interference from the spark plug keeps buggering up my little tach and temp gauge on my bike and it runs like a dog with the resistor spark plugs and cap so trying to avoid that at all costs.

i sorta dodgied it up by wrapping both the leads of the tach and temp gauge in tin foil which worked sometimes, whats a better way to fix it?

was thinking some kind of hollow braid and bolt it to the frame at one end. can you get something like that? like the braid for coax by itself.

cheers
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Post Sun Nov 01, 2009 9:03 am 
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DumHed
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you can get braided tube stuff, or you could rewire it with braided cables maybe?
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Post Sun Nov 01, 2009 5:52 pm 
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Glen
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Looking at water injection for a project.

thinking of using say a car fuel injector to blast atomized water into the place it needs to be. first is such a thing possible (id say so but better to be sure eh)

and 2x whats required in driving a fuel injector? i dont particularly need it to PWM just be completely on or completely off. i was hoping to have it turn on at a minimum RPM that could be sensed off an ignition lead. Does that sound like something a PIC or PICAXE could do?

IIRC pyrobot was using an injector for its flamethrower? any insight on how that works gary? Smile

never done a decent programming project so it could be fairly simple and a good place to start Smile

cheers
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Post Sat Dec 05, 2009 3:37 pm 
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DumHed
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electrically there are two types of injectors - low impedance and high impedance.

High impedance ones are usually around 12-14 ohms, so you can drive them directly from 12v at about 1A.

Low impedance injectors are 1-2 ohms, and are usually driven with a resistor in series, or by a "peak and hold" driver that gives them a high current pulse then drops to a low duty cycle PWM.


I'm not sure how long injectors will last when used with water, but they'll probably be ok for a while at least Smile
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Post Sat Dec 05, 2009 4:13 pm 
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Rotwang
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Just a windscreen washer pump, normally one with the bottle attached and a garden spray type humidifier nozzle are the go or a header tank type bottle pressurized with air and a electric valve of some kind feeding the nozzle.
Put a non-return valve in the water pipe close as possible to the nozzle so it can’t drain back and cause lag.

Trick is switching it only when the engine is likely to ping, high load low revs type of thing, MAP sensor and RPM and maybe TPS imputes.

Gets a little trickier with forced induction.

Don’t like the idea of water through an injector but I haven’t tried it.
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Post Sat Dec 05, 2009 5:32 pm 
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Glen
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fair enough. its a water injector in to the header pipe of a 2 stroke, so i was thinking injector, but using a carby jet in a little boss welded on to the pipe would work too. so a washer pump would probably work good in that application.

ill give it a goo after the robots done

cheers Smile
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Post Sat Dec 05, 2009 6:24 pm 
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Nick
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Given that you won't need to spray much water, you could use a pressurised aluminium tank with a tyre valve on the top. Its simpler to control and I hear that the best water injection systems us high pressure for finer droplets.

Post Sat Dec 05, 2009 6:54 pm 
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Valen
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I'd go with nicks idea and a fuel injector probably the easiest way to get enough pressure for decent atomization, ey why not run some NOS in along side ;-> .
although they are running pretty high pressures these days I believe

fill it
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Post Sat Dec 05, 2009 8:07 pm 
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Nick
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This looks promising: http://images.google.com.au/imgres?imgurl=http://www.alcohol-injection.com/images/In-Nozzle.jpg&imgrefurl=http://www.alcohol-injection.com/inside-mount-nozzles-7.html&usg=__De1NIcblak7ZMZUivQIvJvzUBYQ=&h=466&w=600&sz=27&hl=en&start=7&um=1&tbnid=EQZD_JhPIMLrdM:&tbnh=105&tbnw=135&prev=/images%3Fq%3Dwater%2Bmist%2Bnozzle%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-GB:official%26sa%3DX%26um%3D1

Its just the first one of thousands of sites with relevant parts. The trick will be knowing how much water to inject.

Post Sat Dec 05, 2009 10:20 pm 
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Rotwang
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Just glanced at their stuff, it looks like it operates at relatively high pressure. Good if it’s spraying into a forced induction intake but needing 250 psi to operate is getting a bit extravagant for normally aspirated use.
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Post Sun Dec 06, 2009 7:13 am 
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