power supply vs. battery charger?

[dog812]

What is the difference between a simple battery charger
Input: 120VAC / 60Hz
Output :6VDC / 500mA

And a power supply with same specs?

I am buying RC battery chargers and having to replace the tamiya connector , when i can buy a power supply for cheaper with the proper barrel connector i need..
Is it possible? any info would be awesome!!
**broken link removed**
**broken link removed**

 

[dknguyen]

Such a power supply will provide a constant 6V up to 500mA output. That's it. That's all it does.

A battery charger like that though could provide 6V at 500mA if needed, but most of the time does not. Instead, what it does is constantly adjust the voltage (up to a maximum of 6V) in order to control the amount of current that flows into the battery so that it does not charge the battery too fast and damage or explode it.

 

[bokbaard]

I didnt even know that the simple wall wart type charges have current control.
What kind of circuit do they use to control current (by varying voltage I presume) ?

 

[chrisjpitt]

I didnt even know that the simple wall wart type charges have current control.
What kind of circuit do they use to control current (by varying voltage I presume) ?

Nothing very exciting - most cheap "slow" NiCd or NiMH chargers just use a resistor (after the rectifier), to give a constant(ish) current to the battery.

 

[dog812]

That is too bad.. i was hoping that would be a good solution.
Oh well ill just have to keep lookig.. thanks for the info.

 

[audioguru]

You showed the pic of a cheap wall-wart power supply.
Its output voltage is 6V only when its load is 500mA.
Its voltage is not regulated so its output voltage might be 10V with a load of 100mA and its output voltage might be 12V when it has a low load current.

It doesn't regulate the output current. If the load draws more than 500mA (which a battery probably will do when it is charging) then the cheap power supply might get too hot and set your house on fire.

A battery charger has a circuit inside that is made for charging a certain type of battery.

 

[dog812]

Yah taht is what i was afraid of.. i dont want to burn down my house to save a couple bux.