Go Down

Topic: Powering 3 servos & what's everyone using on their workbench? (Read 2 times) previous topic - next topic

MarkT

Quote
Only fear it if it manages to go across your heart or brain; other than that, it's just pain. Paying attention to the "one hand" rule will keep it from crossing your heart;


I think you're being rather optimistic there - if the one-hand rule was safe people would not die like this:
http://www.raib.gov.uk/cms_resources.cfm?file=/070529_R142007_Deal.pdf

Note paragraph 120 on page 30 - left arm and left leg only, 650 to 750V DC.  Admittedly more voltage, but we have 240V here ;)
[ I won't respond to messages, use the forum please ]

Joonazan

Voltages below 20v are pretty safe, and unless the transformer is home-made or ripped open it is safe too.

earlbotics

That build into the KVM case is great!
This is interesting to me, I posted another thread about my project involving 10 futaba s3003's and intending to use an "atx" power supply from a Mac G4 tower (it's slightly different but pretty much the same as a standard PSU)  and I've been testing but have real problems powering even up to 3 servos, the over current protection is way too sensitive.  It says it has 20A of 5V to give me which should technically be capable but alas I have power woes and a project with a looming deadline. 
I may have to run it from batteries but for enough current it will cost me... and the PSU was free! I'm glad I'm not alone thinking this will work but any ideas about what to do? 

jraskell


650 to 750V DC.  Admittedly more voltage, but we have 240V here ;)


That's like comparing a lighter to a blowtorch.

cr0sh



650 to 750V DC.  Admittedly more voltage, but we have 240V here ;)


That's like comparing a lighter to a blowtorch.


I just skimmed that report, and that was my thought, too; in that case, it wasn't the voltage, but the current supply - I didn't read the report far enough to know if they mentioned how many amps (likely hundreds, possibly thousands?) the system could supply, but I sincerely doubt that -anything- would've helped. That kind of electrical contact, regardless of where or how it happens almost always results in "instant death" or at best, a very long convalescent period (from which you are never the same again).

When I was speaking of the "one hand rule", I was meaning more in the case of electronics that you would likely find on a workbench.

:)
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

TopScouser

Just a quick question to anyone,

Ive converted an old 300W computer ATX to a bench PSU. I have got +5V, -5V, +12V, -12V, +3.3V. At 5V it gives out around 20A. What would happen if i was to connect a servo to that? would it damage the servo or only draw the current that it needs??

retrolefty


Just a quick question to anyone,

Ive converted an old 300W computer ATX to a bench PSU. I have got +5V, -5V, +12V, -12V, +3.3V. At 5V it gives out around 20A. What would happen if i was to connect a servo to that? would it damage the servo or only draw the current that it needs??


It will only draw the current it demands. Ohm's law says the resistance of the load (times the voltage source) is what determines the current flow. That has no bearing to what the maximum current capacity of the supply is as long as the load draws equal or less then that maximum value.

Lefty


TopScouser

I prob should have know that haha, anyway thanks a lot Lefty, your a hero

Go Up