Power Supply v Battery Charger

[Hot-Nut]

I have a small telephone amplifier, currently powered by a 9V standard battery. There is the option to use a 7V DC 100mA power supply in place of the battery.

I have a spare mains to DC battery charger with an output of 7.2V = 300mA marked with the same polarity as the amp power socket.

Is the battery charger essentially the same thing as a power supply? Should it do the job?

Many thanks.

[ACtheTROLL]

they are different in that a charger generally has battery holders for the batteries you will charge

a power unit plugs in to a device ...

then there is the device which has it's own batt built in ... and then the powersupply is also the charger

in your case
the potential output current is three times the recommended - this doesn't mean that the pu will force 300mA into the amp ... it just means that the amp COULD take 3x what it needs ...

the key number is the voltage

similar to your home mains
the ring supplies 13A @ 240v
it doesn't matter if it's a 3KW heater, or a 40W bulb
the safety is provided by a fuse appropriate to the device.

[Hot-Nut]

Thanks for reply.

I should perhaps have made clear that the item I have labelled as a battery charger does not itself hold batteries. It is simply a small mains plug-in device (looking exactly like a small power supply) with a fly lead to connect to the DC socket of rechargeable equipment.

[ACtheTROLL]

shouln't be a problem I have a 10A variable voltage power supply it has a range of ends ... and I also introduced a fuse holder which holds a range of appropriate fuses

using an overrated power supply only matters if the device goes faulty.