Science/Engineering/Technical forums

For the past two years I have been competiting in an international robotics competition known simply as Vex Robotics Competition. Each year the engineers at Vex come up with a challenge and then high schools from around the world build robots to compete against each other centered around the ...

Hey guys,

Sorry for my late input into the particular topic, but I have some first hand experience so I'll try to lend what I can.

In middle school I began constructing and testing several pulse jets and ram jets, I found them absolutely mystifying so I decided to build a turbojet. I ended up ...

Doug,

First off, I think it's great that you've gotten this thread started, because I think we (especially myself) could use a much "engineered" (further improved etc. etc.) way to do this.

Secondly, I got Alexi's controller functioning properly on my pump last week but since, I have noticed a ...

WOW! Simply amazing work on this one Doug, I can't wait to see how it turns out. I coated several grids in graphite today, baked them, and was very pleased with the results I got. I'll be test three different types of brides this weekend (during an experiment on secondary emission) and I'll be sure ...

After probing around agian, I found that one of the leads was messed up and some things were wired in the wrong order. Now the thing seems to be running properly, it starts to spin up, gets pretty fast, then slows down. I'm working now on putting it under vacuum to see how fast it'll get. I guess it ...

So I got the new ICs in this week and replaced both the SN7474 and the SN7400 that Alexi's Turbo Pump controller calls for. I began testing the pump today and encountered some odd results. I captured what is going on and posted it on youtube so you guys could see:
LduZqyCbv-M
Any ideas on what is ...

Yeah, stuff happens at a incredibely high frequency when I start dealing with electronics. Tyler gave me instructions for testing the chip so I'll be trying that out as soon as I get home from robotics team practice. Details will be posted here later tonight.

-Chad

Yeah, I was able to read the hall sensor with a scope and it seemed fine. The majority of the hold up with the circuit has been the recent discovery that I had the 7474 chip wired backwards in the circuit. :oops: I'm in the process of rebuilding the circuit with high hopes of it actually working ...

Jerry,

Ah ha. Yes, I just began reading one of the articles the author cited and realized that. I remember some (I think it was you actually) citing the amtel chips earlier on in the discussion. I'm going to check those out and see if I can use one of their application schematics.

I've tried Alex ...

On the topic of controlling an tph 055 with a l6234 chip:
I used the great google to search around the internet for a circuit that I could build a controller suitable for a pump off of the l6234. I found this article of instructables.com http://www.instructables.com/id/BLDC-Motor-Control-with ...