Constant Power source...?

[Philly]

Whats up peeps...?

Hi....

I did a bit of a search but couldn't find a definite yes or no to this.

Is it possible to hook my KHR 2 up to a constant power source? It is very tricky trying to learn how to, and then actually program him when the standard battery keeps going flat after 30mins.

I did read a few things about higher spec battery's so if the answer to this post is "no" then that will be my next choice.

This guy seems to be hooked up to a power source, no?

http://www.youtube.com/watch?v=D6ipf1ij_lg

[Robo1]

You can use a power supply, have a look at this link ebay if that doesn't work search ebay for Mastech. I've had a couple of these power supplys and they good. Get one with something like 0-30V and 6amps. I like and have the 3005F-3 just because it's useful having 2 seperate outputs. But something like the HY3006D would do the job, I also have one of these.

the advantage of these power supplys is that you can adjust the current so if it goes to high the circuit turns of.

Bren

[Philly]

Bren, that is the best news I have had all year! I had no idea this was possible until I saw that youtube clip. This is going to make programing an absolute pleasure...!

Thanks so much!

[Philly]

Bren (and everyone else!),

I have further questions now (of course...);

I'm not that knowledgable with volts and amps. My brother is, but he has never built or used a robot so I can refer to him but I want to get some facts from you guys.

I have read some posts and from what I can gather, the voltage of the KHR-2 is 9-12v but I cant seem to find a definite answer on the current drawn. Obviously I don't want to make any mistakes here...

All the posts I found dated back a while so I'm wondering if there is one school of thought on this now.

All help is very much appreciated!

Thanks


edit: just read this thread - http://robosavvy.com/forum/viewtopic.ph ... ht=current

it links to the desktop PSU from Maplin. It's only £49.99 Should I put it on my christmas list?

[Robo1]

Hi

I wouldn't go for the maplin power supply go for one of the ones I linked to, this give you tha advantage of changing the voltage and ampare.

I would run the KHR at 11V as for amp should be fine at around 4 amps. Your only draw more if you stall a servo so having a power supply with short circcuit pretection would be a bonous.

Bren

[Philly]

Thanks Bren,

I'm a little confused of Amps, though I doubt anyone can teach me what I need to know in a few short sentences.

I'm having a hard time understanding the current drawn. If it was a light bulb, it would switch on and stay at a constant power. But with the KHR (any robot) there are all these servos moving at different times so doesn't the amperage change? And if it does, what happens? Does the power supply let it?

I'm not necessarily expecting anyone to explain this to me. It would be great if someone could, though I'm planning on finding a night class in electronics to get me somewhere up to speed. Quite important I imagine...

Bren, the reason the Maplin one caught my eye was because of the price, and because it is so easy to get (30 minute walk from my house). Also i thought it would provide the right amount of power. It only runs to 5 amps though. Your suggesting 6. I need to have a good look at it and then at the Mastechs so that I understand the difference.

[Robo1]

A little lesson,

The amp will change depending on what the bipeds doing. when it's lying on it's back it will be using a low amount of eneragy e.g. amp. When it's running around it will need more power/amp, around 2.5 -3A. The power supply will supply the amount of amp it needs but if the robot stalls it will try and take lots of power/amp 4A+. this is where a good power supply comes in. with a short circuit protector, when the robot trys to draw alot of power it will turn of e.g. saving your servos from being destoyed. On a good power supply like the maplin one, you can adjust the make amp so you can adjust it to where the normal pwer level is, and if the robot trys to use more power turns it off to save the servo's.

The maplin one will work it just looks a bit cheap to me, but that's maplins style. 3 amps is the lowest you can go for but will do the job. I only said 6 amps as theres not much difference in price from 3 to 6 amps so I would go for the higher amps.

The ones I linked to arn't that expensive (£100), plus they have the benifit of retaining there value for resale over the maplin one.

just my thoughts.

Bren

[Philly]

Thanks Bren, that was a nice explanation and I know understand what the deal is.

I'm still searching through ebay for the Mastech's but the only suitable ones I can find are overseas. I'm going to do a google search to see what I can find within the UK.

Bren, Thanks again for your time, help and advice. I feel much better equipped now to go out and find what I need. It's going to be so much easier to program it now.

Sincerely,

Philip

[Robo1]

Do a search on google using the key word:

bench power supply

this will give you a list of most power supply, the make I gave you is a generic brand, but most common on ebay.

Bren, Thanks again for your time, help and advice.

Thats alright I'm bored at work.

Bren

[Philly]

Bren,

Just wanted to let you know...

My Nephew (and his mum and dad) bought me a bench top power supply for my christmas present. It wasn't one of the one's you mentioned but it seems pretty good to me. Does just the job. Here's my set up now:

Tenma Bench Top Power Supply - 1-20vDC 0-6A
It's quite accurate and has Short Circuit Protection/Over Temp. Protection/Tracking OVP

For running Heart2Heart I am now using my Mac G4 Powerbook. For all the years I have had it I had no idea I could run windows on it. I had bought a 2nd hand PC laptop to work from and I disliked how un-smooth it was. Now everything is flowing along nicely with a quality computer and constant power supply. It makes such a difference. I can really concentrate on what I'm doing.

Just yesterday I installed a TEC-3 wireless receiver from HotProceed. I haven't tried it yet as I have been busy but if that goes ok then I really am up and running.

Thanks ever so much for spending the time advising me on all my earlier questions about the PSU. It is very much appreciated.

Philip