mAh to amps?

[dude8604]

I need an AC adaptor that outputs 800mAh at 12 volts. However, most AC adaptors don't specify mAh. What amps/volts should it say for output on the adaptor? Btw, this is for a mini RC helicopter. Thanks!

 

[Walleye]

Originally posted by: dude8604
I need an AC adaptor that outputs 800mAh at 12 volts. However, most AC adaptors don't specify mAh. What amps/volts should it say for output on the adaptor? Btw, this is for a mini RC helicopter. Thanks!

why did i read m4h to amps?

 

[PrincessGuard]

A mAh rating is pointless for an AC adapter because it essentially has unlimited power.

A 800mAh battery can supply 800mA for 1 hour before it is drained. A 800mA transformer can supply 800mA for as long as it is plugged in.

 

[Harvey]

mAh means milAmp hours, or how much current a battery can deliver (in mA) for how long (in hours). 1 Amp = 1000 mA. A supply that provides up to 800 mA is the same as one that provides up to 0.80 A. Just find an adapter that provides 12 V @ 800 mA.

 

[dude8604]

Originally posted by: PrincessGuard
A mAh rating is pointless for an AC adapter because it essentially has unlimited power.

A 800mAh battery can supply 800mA for 1 hour before it is drained. A 800mA transformer can supply 800mA for as long as it is plugged in.

so an 800mA 12v adapter should work?

 

[Harvey]

Here's one from All Electronics

12 VDC 1.25 AMP SWITCHING SUPPLY
CAT# PS-1215
$ 7.25 each

If you can use one that's unregulated, here's one from Jameco Electronics. Unregulated means the voltage may vary under load.

AC-to-DC Unregulated Wall Transformer (Adapter)

TRANS,WALL,12VDC/1000mA,F2,

Jameco #100870
Mfg Ref # EVERDDU120100
$7.95

One word of caution -- Adapters like these can have connectors with either the center or outside ring as the hot (positive) terminal. Be very sure you know which your RC helicopter requires, or you could damage it.

 

[Analog]

Originally posted by: dude8604

Originally posted by: PrincessGuard
A mAh rating is pointless for an AC adapter because it essentially has unlimited power.

A 800mAh battery can supply 800mA for 1 hour before it is drained. A 800mA transformer can supply 800mA for as long as it is plugged in.

so an 800mA 12v adapter should work?

probably, but not necessarily. The current draw on the batteries may be -much- higher than the adaptor, the batteries just wouldn't last very long. Look at the application, check the power requirements before jumping.

 

[Amorphus]

well, there is a cap at which the AC adapter cannot handle any more current, so basically look for a maximum wattage output and divide by 12.

 

[kt]

Any AC adapter that outputs 12 volts DC and any rating higher than 800mAh. As long as the device doesn't draw more power than the AC adapter are able to supply, it will be fine.