Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 05-11-2008, 12:02 AM   #1
Newbie
 
Join Date: May 2008
Posts: 2
Rewards Points: 10
Question

How to determine DC amperage required for small device?


Hello,
I've got a nice salvaged radio that had it's cord cut off. All I know is that it requires 12V DC (it's labeled 12v DC).

What I'm curious about is the best way to determine what amperage is required without frying it.

Can anyone help me with this, otherwise I'm guess I'll start by hooking it up to a 500mA supply and see if it works?

Any help would be greatly appreciated!

quexal is offline   Reply With Quote
Old 05-11-2008, 05:46 AM   #2
Member
 
Join Date: Mar 2006
Posts: 682
Rewards Points: 500
Default

How to determine DC amperage required for small device?


You could hook the device up to a power supply that you know is too big, then use a good meter to measure the amperage it is using. (remember to measure amperage is series)

If the device is in good condition it will not draw more amperage than it needs while hooked up to the proper voltage.

__________________
Master Electrician
jwhite is offline   Reply With Quote
Old 05-11-2008, 11:39 AM   #3
Idiot Emeritus
 
Join Date: Mar 2008
Location: Fernley, Nevada (near Reno)
Posts: 1,623
Rewards Points: 1,040
Default

How to determine DC amperage required for small device?


If the radio is very old and uses vacuum tubes, it'll need about 5 or 6 amps. If it's solid-state, it'll likely be less than 1 amp.

As stated above, the best way to determine current is to connect it, and measure current. If the capacity of the source is huge, (like a car battery), make sure there's a fuse of some sort in series with the radio wires.

Remember, polarity is important with DC power. Reverse polarity will destroy semiconductors (transistors and the like).

Rob
micromind is offline   Reply With Quote
Old 05-11-2008, 01:04 PM   #4
Newbie
 
Join Date: May 2008
Posts: 2
Rewards Points: 10
Thumbs up

How to determine DC amperage required for small device?


Hi again,
Thank you both for your excellent and quick replies! I'm much more confident now.

I'll grab a 12v 1A power supply today and test it out!

Thanks again!
quexal is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How can I determine service amperage? dawho1 Electrical 13 04-07-2008 10:10 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.