Corvis (temp bot name) rough ideas.

[daveimi]

So how come you need this in the design?

[Bacon Wizard]

Need? This is Robot WAR. It's not about doing the minimum required, it's about making your opponent cry like a girl in the arena, then going for a pint afterwards. Nobody NEEDS better weapons, faster speed, more grip.. but it's all a bloody good idea if you can get it, no?


I have one, single, serious motor. It's an Etek and is driving my pneumatics and the weapon. ie, everything.

It can run on anything between 12v and 96v providing it's cooled and that the time is kept shorter with high voltages. 10Hp @ 48v

I could stick with what it will do without such measures.. but why the hell would I limit my bot to that? I want to smash the crap out of my opponent up to the point where I've won the bout, not politely tickle it and then wait in line for my turn. I want to shove them wholesale into the wall so that they're left dizzy and nauseas, not just amble to my death. I want the weapon to knock them into next century.

I want to be faster, stronger, more mental.. if I have a chance to squeeze a bit more out of my motor when I need it, I'm taking it. My design is already dodgy enough, being a walker. I'm not going to muck-about with anything else. I'm taking every advantage I can.

Frankly, I am a newbie at this, but working out a circuit that can instantly turn 24v into 72v (minus losses) wasn't hard, and I don't understand why everyone doesn't have that option. The weight of the circuit isn't significant for a heavy.

My 3 x 24v battery packs will be in parallel, and most of the time I'll want to keep it to 24v, and last the distance.

But when I absolutely need to treble my output, it's there for me, instantly.

[Max]

Will you not be exceeding the 50v AC maximum rule wity your design? I don't fully understand it but it sounds like you are turning it to AC, bringing it up to 72v then converting it back to DC. 72V AC obviously excess 50v AC

[daveimi]

It just seems a bit "over-engineered" ie...why do you need an inductor simply to bring in more voltage (which you could do with a simple remote switch)? As engineering apprentices at 16 we were given the train of thought that in most cases simplicity will equate into reliability.

[Bacon Wizard]

Max, DC boosting is well-known, normal, ordinary and old (WW2)

All you have to do is turn the supply on to charge caps, and turn it off again to discharge them. You don't even have to turn the DC off, just re-route it.

Intermittent or unregulated DC is way different than AC.

[Bacon Wizard]

It just seems a bit "over-engineered" ie...why do you need an inductor simply to bring in more voltage (which you could do with a simple remote switch)? As engineering apprentices at 16 we were given the train of thought that in most cases simplicity will equate into reliability.

That might be right. I'd just like to smooth the supply out after the result, and I don't want to treble the voltage at a third of the duty-cycle or third of the amperage, either. It seems to me that an inductor is useful.

[daveimi]

If you want to run 24V with bursts of 72V, surely it's as simple as using a remote switch to bring the other two packs in series with the circuit?

I understand you want bigger and badder, it's the DC - AC conversions and Inductor packs I don't see the point of. It's quite probably in my ignorance, but is there a benefit to using inductance and ac-dc conversion to achieve the step up in voltage?

[Max]

All you have to do is turn the supply on to charge caps, and turn it off again to discharge them. You don't even have to turn the DC off, just re-route it if it were really necessary. If that were considered AC, then anything binary in nature will need to be banned.

Ok that's fine, I thought you were converting it to AC and didn't want you to be caught out by the rules. Although I imagine this concerns the "loopholes" part of the rules so you should ask if it is acceptable before building and I would also ask the event organisers if they are happy to have a 200kg robot in their arena- there aren't any superheavyweights for a reason.

[Bacon Wizard]

Ok that's fine, I thought you were converting it to AC and didn't want you to be caught out by the rules. Although I imagine this concerns the "loopholes" part of the rules so you should ask if it is acceptable before building and I would also ask the event organisers if they are happy to have a 200kg robot in their arena- there aren't any superheavyweights for a reason.

It's a walker. double weight allowance. I think it's pretty much established that a 200K walker is ok, if it's within the regs.

It's not the weight of the robot that's a problem per-se I don't think, it's the power of weaponry and mass of flying bits against the arena wall. But yeah, EO always get the final say of course.

I bet the whole voltages thing is about fire safety more than anything, but I'm in the habit of asking these things, yeah.

[Bacon Wizard]

If you want to run 24V with bursts of 72V, surely it's as simple as using a remote switch to bring the other two packs in series with the circuit?

I understand you want bigger and badder, it's the DC - AC conversions and Inductor packs I don't see the point of. It's quite probably in my ignorance, but is there a benefit to using inductance and ac-dc conversion to achieve the step up in voltage?

Not using AC conversion.

But in answer to your question, the regs limit the number of battery cells that can be wired in-series. You can't get anything like 72v by doing that.