Volt regulators such as the LM708, and LM317 series (and others) sometimes need to provide a little bit more current then they actually can handle. If that is the case, this little circuit can help ...

Solenoids at turn-on draw currentthat is much higher than the currentneeded to keep the armature pulledin. Further, because of the power dissipatedin the coil, the solenoid’s temperaturewill rise, and ...