Broadcom ACHS-7123

While taking my BOM to Mouser to plan a parts order, I found that one of my preferred board mount current sensors, the Tamura L18P030S05R isn’t currently available in low quantities.  Fortunately, there is an equivalent hall effect type current sensor that comes in a smaller, cheaper smd component, the Broadcom ACHS-7123.  I prefer this technology over shunt type current sensors, as I think that they are, overall, cheaper, more accurate, and smaller, and this “new to me” Broadcom chip is a fine example of that.

Using My Analog Signal Multiplier As a Platform

If you take a close look at my PIC based signal multiplier, it becomes apparent how easily that same design can be used for multiple DC analog (0-5)V signal manipulations, logic, and transforms.  The chip consists of two protected DC analog (0-5)V signal inputs, and one PPTC protected DC analog output (0.4-4.6)V which is determined in the microprocessor programming by the duty cycle of the PWM output.  Because the output is put through a power op-amp follower, the output signal has some decent power behind it.  Thus, by modifying the PIC program, the device has a much wider range of possible uses that would otherwise require complicated and component intensive circuits to implement.

So the next time you’re thinking of building an analog circuit with 3+ opamps, you might consider this little guy, instead.  You can contact me for a custom solution at


Operating System Shuffle

I got some software that I’d figured would be easier to run straight out of a windows operating system, rather than through an emulator, so I decided to try to rig up my debian machine with a windows dual boot. So I get the windows 10 iso and write it to a usb key to act as an install disk, something which I had done to install debian on this laptop in the first place. But now, it’s not working. I can’t get bios to find the usb efi file. I don’t want to go out and buy blank dvds, so I rigged up a virtual machine with VirtualBox in debian. On the first try I used a virtual hard disk (vhd) type of too large a fixed size. I didn’t have the space to have VBoxManage convert the thing to into raw format for dd onto the hard drive, and qemu-nbd doesn’t support vhd. So I gotta delete that image, start over with a vdi format virtual disk of a smaller size. This works alright, but for some reason my windows 10 iso isn’t working anymore, says it can’t find drivers. So I download a fresh windows 10 iso and get installed on the new smaller virtual disk. Hopefully, I’ll be able to dd it onto a spare partition I got, grub-update, and I’ll have a working dual boot machine, but if it won’t work, I’ll still have the VirtualBox in debian which can provide full windows experience at a reduced speed.

Alas, the boot configuration files from the VirtualBox vdi won’t work on the hard drive, and editing them is problematic. It can probably be done with the right grub drive mapping and chainloading, but a promising alternative is to use grub loopback to mount the windows 10 iso straight from a location on the hard drive, which I have this evening found to work very well for linux install disks but getting the windows disk to work with ntldr or chainloader remains illusive. In the meantime, there’s always the option of just burning a dvd, but in the meantime I can still work in the virtual windows machine.