Why is the current on a negative power supply rail always so small, and does this matter?
I am working on some simple DC experiments and just generally screwing around with electricity, and I was wondering why the amperage rating on negative power supply rails is always only a few hundred milliamperes. If I want to provide 24VDC for a circuit by using +12v and -12v (is this correct?) am I limited to the current of the -12v rail? How does this work? Thanks.
If you want 24 volts, you use a 24 volt supply, with (usually) – tied to ground and + tied to the load.
But you could bridge between –12 and +12 to get 24v, it depends on what the circuit is. Usually the first is the only solution, but sometimes the ±12 volt approach will work. If you do bridge between the ±12 volts supplies, you are limited to the current in the least capable supply, here the –12 volt one.
Usually the power demands for the –12 volt supply are light (for PCs) so that is why it is a low power supply.
.
Deck Estimates. FREE Estimates From Waterproof Deck Expert
|
|
Dell Optiplex Dimension HDD Rails 21TUG 87VYR w/ Screws $0.95 |
|
|
IBM NetVista Hard Drive Rail Kit w/screws 33L2740 NEW $3.98 |
|
|
Tactical AK Picatinny Rail Side Mount System Screw Sty $34.99 |
|
|
IBM Thinkpad T60 T60p Hard Drive Cover Caddy Rail Screw $10.49 |
|
|
Dell Dimension Floppy Rails 995EM 26PNP with Screws $0.01 |
|
|
REAR FENDER RAIL CAP SCREW KIT Harley Sportster FX $19.75 |
|
|
NEW! POLY BINS RAIL SCREWS NUTS BOLTS PARTS BIN STORAGE $22.47 |
|
|
Hard Drive Caddy (Rails) & Screws f/ 12″ G3 iBook A1005 $9.95 |
|
|
10 Dell Plastic Drive Rails with 20 screws 87VYR 21TUG $10.00 |
|
|
Lot of 5 pairs Dell green hard drive rails with screws $0.99 |
|
|
Stanley Home Designs Handrail Bracket … |
|
|
Home Cabinet and Drawer Template with Drill Bit – Green (16) $7.49 … |
|
|
Home Victorian Glass Knob – 4 Pack $14.99 … |
|
|
Festool 489570 Screw Clamps, 4-11/16 $35.00 Use to secure bench mounted devices. Clamping capacity 4-3/4″(120mm). Comes as a pack of 2…. |
|
|
Chamberlain 7806CB Screw Drive Extension Kit for 8-Feet High Garage Doors $29.62 For 8′ and 10′ high garage doors. Use with Do it Best private label or Chamberlain garage door operators. The 8′ and 10′ chain drive SSR kit works with model No. 4500DID, 4500DI 2D, 6502DBD, CG40D, and PD752D. The 8′ and 10′ belt drive SSR kit works with… |
0 responses so far ↓
There are no comments yet...Kick things off by filling out the form below.