voltage demand vs supply

[ericwalker]

I have a game circuit board that requires 6v 300mA. Can I use a 5.9v 350mA plug in adaptor? Will it blow the board?

 

[alec_t]

Assuming the board's 6V is DC and the adaptor supplies DC it won't blow the board: but 300mA is close to the max the adaptor is rated for, so the adapter might run rather warm.

 

[ericwalker]

Thanks...even though the adaptor is rated for 350mA it will still run warm? The board only calls for 300mA...Going a step further, can I run the 6v adaptor to a 12v 18ahr sealed battery? I would like to be mobile?

 

[KeepItSimpleStupid]

The adapter is likely an AC (wall) to DC adapter. At least this is what we are likely assuming. If so, the answer is no.

Why would you run the adapter to a battery?

You can, however, use a DC to DC converter to drop the 12 V efficiently down to 6V. Lots of these are available on ebay.
I bought a number of these **broken link removed** and they work very well. You can set the current limit and it measures current and is 90% efficient.

It's called a step-down regulator because the source voltage has to be 2 V above the desired voltage.

==

This BIGGER typr of question you asked comes up from time to time. An example is you car battery can possibly supply 400 A and the light bulb does not complain. We just don't run wires rated 400 Amps to a 5 W light bulb, but we "protect" the wiring with a fuse.

Your house is another example. You have maybe 200 A at 120 V available per split phase, yet you plug in a 7W night light.

 

[ericwalker]

Thanks again. I just bought 2. I do interactive events and am going to use these with my skeeball and other table games to be mobile. The games run on adaptors rated for 6 volts yet I have 12vdc sealed batteries. Is there a stepper that goes 12v ac adaptor to 12vdc?

 

[KeepItSimpleStupid]

Is there a stepper that goes 12v ac adaptor to 12vdc?

Is there a typo here? Do you want to charge the batteries from 120V? Are you looking for a 120 VAC to 12 VDC?

or something else?

 

[alec_t]

even though the adaptor is rated for 350mA it will still run warm?

Probably. Some manufacturers are a tad optimistic, or downright misleading, with power ratings. For example, you may find in the small print that 350mA is 'peak current', or 'intermittent use', rather than sustained current. It's always good to allow a healthy safety margin.