Bipolar power supply for battery instruments


Posted on Apr 1, 2013

To generate regulated ± 5-V supplies from a pair of dry batteries, the circuit of Fig. 1 is commonly used. In order to give protection from inadvertent reverse connection of a battery, a diode in series with each battery would produce an unacceptable voltage drop. The more effective approach is to fit diodes Dl and D2 as shown in Fig. 2, in parallel with each battery. When the supply is switched off, there is the risk of a reverse bias being applied across the regulators, if there is significant inductance or capacitance in the load circuit.


Bipolar power supply for battery instruments
Click here to download the full size of the above Circuit.

Diodes across the regulators prevent damage. When the power supply is switched on, the two switches do not act in unison. There is a probability that one or the other regulators will be latched hard off by the other. To prevent this, D3 and D4 are Zener diodes so that ± 5-V rails are pulled up by the batteries until the regulators establish the correct levels.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Fuzz Guitar Effect circuit
    Increased Feedback-Stabilized Amplifier
    5v regulator circuit using lm105
    Random Musings
    Transistor current limit circuit power handling
    FM Wireless HI-FI circuit
    Night security light
    UPB1008K NECs LOW POWER GPS RF RECEIVER
    Modular Burglar Alarm Project
    Using STK3048 and STK6153 practical circuit
    Irons circuit



    Top