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lorne green

Well Known Member
Thinking forward to the 'lectrical part of this build...I know that I don't want to test circuits using a battery and charger. So I'm thinking of a variable voltage (0-12v) variable Amperage (0-?a) power supply. I know these are more expensive than fixed (v+a) units. I need schoolin' :D
Where's an electrical engineer when you need one. Hey, Vern, you out there? ;)
 
I just use a Radio Shack 14 volt, 15 AMP supply.

http://www.radioshack.com/product/i...ower+supply&kw=power+supply&parentPage=search

You can probably find a better supply for less money elsewhere but I was excited to play with my new stobes, and Radio Shack happened to be open late, etc...

A constant voltage supply would be useful for testing low voltage/high voltage situations. By constant voltage I mean you set the voltage setpoint (it's variable) and then the power supply maintains that voltage by varrying the current.

You probably don't want to fool with a contant current supply unless you know what you're doing. With these, you set the current and the supply varies the voltage to meet that current. Very dangerous if you don't set the voltage limit properly and not all that useful for what we're doing, anyhow.

It's very common for power supplies to run in both constant current and constant voltage mode. You choose which mode you want to run in and set the setpoints and limits.

Something like this would probably work well. I wish I had spent a bit more and bought this instead of the Radio Shack one. I'm totally spoiled by the Agilent (HP) supplies I work with....not enough knobs on the Radio Shack one.

http://www.radios4you.com/mastech-hy3010E.html
 
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john

So, if hook up a 12 volt, 15 amp power supply to a device which should only draw say 2 amps (ei: led lights?) would I cause any damage to the device? (OK these forums are all about educating and you're looking at one dumb shmuck when it comes to electrics :eek: )
 
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lorne green said:
So, if hook up a 12 volt, 15 amp power supply to a device with would/should only draw say 2 amps (ei: led lights?) would I cause any damage to the device? (OK these forums are all about educating and you're looking at one dumb shmuck when it comes to electrics :eek: )
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Unless there is a problem with device, you wont hurt it. LED's take a power supply to regulate the current though, so, if you hook up an led directly it will pop.
I am sure others on here could recomend a good electricity/electronics book to help you learn basic theory. I would not tackle wiring an airplane without some basic understanding of Power, Current, Voltage, Wire Size, and Circuit protections.
 
lorne green said:
So, if hook up a 12 volt, 15 amp power supply to a device with would/should only draw say 2 amps (ei: led lights?) would I cause any damage to the device? (OK these forums are all about educating and you're looking at one dumb shmuck when it comes to electrics :eek: )
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A 12 volt 15 amp power supply is regulated to supply 12 volts at any current up to 15 amps. It does not supply 15 amps all of the time, only what is needed.

If you go fixed, you want a 13.8V supply. That's typically what you're regulating to when the engine is turning the alternator in your plane.

Early in my project I purchased a 20 amp, 13.8V power supply to do all of my electrical testing and prototyping with. (I'm making my own position lights, etc.) It's not the best power supply available, but so far has been reliable so far. I sprung for the 20A model because it has a guage to tell me at a glance how much current is being drawn.

Here's a link to the vendor/model I'm using. YMMV.
http://www.etronics.com/product.asp?stk_code=pyrps21kx&store=&catid=4071

Regards,
Guy
 
Many of the RV folks have made use of the "AeroElectric Connection" - Bob Nuckolls book. See his web site under the same name. He also contributes on a daily basis to another web forum devoted to airplane electrical systems - see
http://www.matronics.com/listbrowse/aeroelectric-list

I knew relatively little about electrical systems, but after absorbing Bob's book and hanging around his web forum for awhile, I was able to complete my electrical system with confidence.

By the way, there was a couple of recent posts on his forum regarding acceptable regulated power supplies. These units are common on e-bay.

erich weaver
 
Thanks guy, I was concerned about cooking stuff with too many amps. I'll do some reading. VAF forums rock. Thanks again.
 
There is nothing wrong with using a battery

lorne green said:
Thinking forward to the 'lectrical part of this build...I know that I don't want to test circuits using a battery and charger. So I'm thinking of a variable voltage (0-12v) variable Amperage (0-?a) power supply. I know these are more expensive than fixed (v+a) units. I need schoolin' :D
Where's an electrical engineer when you need one. Hey, Vern, you out there? ;)
Click to expand...

They are cheep (you don't need a new one. I got mine for $10.00) and put a trickle charger on it from time-to-time. Just remember to use a fuse in-line with anything you will be testing.

Kent
 
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