Replacing a battery with DC transformer

[impakt]

I'm using a 9V rechargable battery but after many recharges the efficiency of the battery is getting lower. Also I need the battery as long as possible to power some componenents which have a lot of current compsuntion. So I was thinking instead of using a battery, I could use a 9V DC transformer, and with the right connectors I could power my components directly from the transformer . Is is ok to do that? On the battery it says this: 9V DC 150mAh and on the transformerower: 5W
Output: DC 3-4.5-6-7.5-9-12V(selected through a switch) Current: 300mA :!:.

 

[Miguel Gaspar]

replacing a battery

You must use a filter first, never conect the transformer direct to your circuit, you must put first a resistor in series with the filter and then your circuits (load). The capacitor of the filter must be big enough form 10 to 100uF is a good value.

 

[impakt]

Re: replacing a battery

The component is in fact a small robot. I'm not much of electronist but someone told me I could use the transformer without any filter switching to 9V or I could switch to 12V and use a LM7809. I need a straight answer so I don't break the robot.