Battery Replacement Power Supply

Posted on Feb 5, 2014

Your child`s battery toy has failed and you have to fix it. Once you have managed to get it apart, the battery compartment is not likely to be connected to the works or the batteries might have gone flat anyway. The solution is this switchable supply which is designed to replace from one to six dry cells. It is not intended to replace the batterie

Battery Replacement Power Supply
Click here to download the full size of the above Circuit.

s on a permanent basis, as in most cases this is not practical. The heart of the supply is an LM317T adjustable 3-terminal regulator and six trimpots selected by switch S1b. The other pole of the switch, S1a, is used to select taps on the transformer secondary, to minimize power dissipation in the LM317T. The table shows the trimpot settings for the six voltage outputs. Diode D1 and the 10 µF capacitor and the LED provide power indication. This has the advantage of constant brightness which would not be obtained if the LED was run from the unregulated switchable DC.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Stroboscope with 555 timer
    Locked Loop Synchronous Demodulator
    RF Recieving Amplifier for 40MHZ
    Increasing the power rating of zener diodes
    20W audio amplifier using TDA7240
    Audio Amplifiers
    Loudspeaking crystal radio receivers
    Tachometer circuit diagram of a multiplier