Please bare in mind that the start-up current or "inrush-current" can be as high as 1.5amps initially,
settling down to a low current of around 800mA, depending on drive manufacturers specifications.
The circuit above can be made using VeroBoard (TM) or on a printed circuit board of the layout as shown below.
The circuit PCB layout (below) can be modified ( if you so wish ) however works fine as it is layed out (below).
It would however, be advisable to spend the time and do it correctly , using a small circuit board and using a
large heat sink to dissipate the heat (as a by-product) of the voltage reduction through the voltage regulators.
Try to keep the secondary Output voltages to , say 5.0 Volts AC at 1.5 amps, 5V x 5V = 10V x 1.414 = 14.14 V DC
thus resulting in less power wasted (dissipated as heat) into a substancial heat sink. Vin must be 2V above Vout.
Current from January 7th 2004
The pictures are on this page are Copyright © 1997 - 2006 Unitech Electronics Pty. Ltd. however, rights to use this page are assigned for use by private individuals only.
Permission ( only in writing ) can be given for links to any graphics to be shown on another web site
EMAIL US at: sales@unitechelectronics.com
Disclaimer: Whilst every effort is made to ensure the accuracy of this circuit, there will be some out there
who will make it and do it wrong, thus destroying their hard drive. We do not make any warranties regarding this
circuit, it is to be used as a "guide only" you alone must determine if it is suitable for "your expertise".
We cannot, nor will not be responsible for any errors or omissions or accidents made in using this circuit.
The circuit was devised here at Unitech, kept as simple and as functionally possible for all folks to use.
using the NE-555 Timer chip.