Feb 142015
 

Today I’ve finally started some work on a self build logic comparator. This is almost identical to the HP 10529a comparator, however instead of only supporting 16 pin logic chips, which is the maximum for the HP, this self build unit will support upto 20 pins. Still got a lot of parts to buy and fit to finish it off, but soldered the first 14 sockets on today, so I’m on my way 🙂

It’s going to be a really useful tool with repairing PCB’s because essentially what it does is compares the outputs of a chip in circuit to a known good chip placed in the tester. It’s perfect for someone who wants to learn more about what the chip functions are and for fault finding chips that can be hard to troubleshoot without a logic analyzer such as decoders (74LS138/139) and various flip flops (74LS74)

The other good thing is that this also supports the standard cards used in the HP comparator, so is backwards compatible 🙂

Logic Comparator