While designing a fan control into another microcontroller project, I stumpled upon this nice design using only an external diode and capacitor. I used a 1N4148 standard diode and a 560pf capacitor.


I will walk through copying a bootable Windows 7 installation from a VirtualBox VM to real iron.

  • Insert an external hard drive in the USB port and share it with your Windows 7 VM.
  • Ask windows to make a system image "Control Panel -> Back up your computer -> Create system image", and save it to the external hard drive.
  • Boot the Windows 7 install disk, click through, and select "Repair windows installation". The drives that you do not put on the exclude list, will be repartitioned and formatted, so make sure to exclude everything you want to keep.
  • Let it chew on your backup, and when done, boot Windows.

Felt like doing a demo effect, I have done this once before in C and asm. The year was something like 1996, and the processor a Cyrix/IBM 6x86 120+. This is slooow, not only because it is written in Python, but because it isn't optimised.

Source: fdtunnel.tar.bz2

On Gentoo I needed to point the configure script at libbfd.so. On my system it is in /usr/lib/binutils/x86\_64-pc-linux-gnu/2.22/ hence:

./configure --prefix=/usr/local/ --with-bfd=/usr/lib/binutils/x86\_64-pc-linux-gnu/2.22/

It has been brought to my attention here that my instruction for building the Single ended class A headamp is not complete.

The transistors in the current mirror, and differential amplifier will benefit from having thermal contact, to keep the temperature difference as small as possible, thereby minimising the DC output offset. I have taken the best picture I could, of this coupling for one channel, in my amplifier.

I have found this tool indespensible, when finding unforseen errors in complex makefiles.


I have built and tested, the revised version of, both the positive, and the tracking negative regulator. The new version is here:

I have not included Q12, since it was part of the original current limiting circuit. The pass transistors Q5 and Q7, are mounted off-board, on a suitable heat sink. R18 adjusts the maximum output voltage, and R17 adjusts the voltage of the negative tracking regulator.

I will do some more testing of the power supply under different load conditions, and post the results.

LAB power supply Eagle files

Generated on 2017-03-19 22:52:04.501033