12 volt power source?

On Sat, 22 Dec 2007 14:38:11 +1300, I said, "Pick a card, any card"


Lead-acid batteries require a minimum of 10% over nominal. That's why 13.8 volts is used to charge a 12 volt lead-acid battery. Applying any less will cause a drain after a very short time. When a battery goes way down, say to 10 volts or so from use, a 12 volt power supply will work up to a point and then become a drain on the battery. At 10% over battery rating, that's 12.0 volts plus 1.2 volts or a minimum of 13.2 volts to sustain a charge and then a trickle. Obviously, 13.8 volts fits that requirement. A unique thing about a lead-acid cell is that you really can't overcharge it unless you are dumb enough to use a constant current charger. The battery presents a smaller and smaller load to the charger as it gets more fully charged. Nature of the beast. -- Ray
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Greg Procter wrote:

Sounds about right!!! A "NORMAL" 'Train Power Supply', will charge an attached 'capacitor' to close to 20 volts, because of the peaks in voltage available for a very small amount of time.
Chuck D.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 20 Dec 2007 17:49:49 -0500, David Starr

I found 12 volts too fast for tortoises so I got an el cheapo train set throttle for a song at a train show - use the throttle to set what seems a good speed and forget it.
These are cheap and can be used for lots of things like layout lighting, signals, crossing gates etc. Anything where you don't need a traction-quality supply.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Carter Braxton wrote:

Carter,
Aren't you glad you asked?
Stevert
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yes, I'm glad I asked... if only to read the energetic exchanges between the group's readers... Thanks to all but especially to David Star who cut straight to my actual question and tells me that using a 16 volt power supply shouldn't hurt a Tortoise motor.
Carter

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Man have you asked the wrong group hehehe...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 22 Dec 2007 00:42:35 GMT, I said, "Pick a card, any card"

Clear your mind. That was easy. No thoughts. -- Ray
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Damn,... I'm sure glad I didn't ask about DC vs DCC
Carter

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

hehehe... right you are!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.