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Constant Current Dummy Load Revised

I revised my EEVblog inspired constant current dummy load.  I was able to improve the performance under higher currents by shortening up some of the traces on the pcb and adding a couple of components. Some of these PCBs didn’t get the back silkscreen of the Golden Driller (or “Tulsa Man” as Dave called it.)

ccdl rev2

Revsied Dummy Load

Here is the complete documentation:

Constant Current Dummy Load rev2 Schematic

Constant Current Dummy Load rev2 BOM

Constant Current Dummy Load rev2 Gerbers

I sold all the kits I had… Hopefully I’ll be able to put some more together soon!

EEVBlog Inspired Constant Current Dummy Load

Many months ago, I watched the EEVBlog posting on building a constant current dummy load.  It seemed like a very useful device to have around, and I planned on building my own, but only got around to it recently.

My version is pretty faithful to the original.  I made a few changes, mainly to decrease cost. For instance, in place of the panel meter, I just put a couple holes where you can insert the leads from a cheap multimeter. I also replaced the pricy multiturn potentiometer with a couple cheap single turn versions which provide a coarse and fine adjustment. (I know Dave hates those!) I think the only performance related change I made was to replace the LM324 op amp with a MCP6004, which has better rail to rail performance.

Here’s a little video of the board, and the schematic and BOM. I have a few PCBs and kit of parts available if you want to build your own. The kit includes PCB and all parts except the 9V battery. Shipping is a flat $5.20 using USPS small priority mail box. I can only ship to customers in the USA with this method.

Constant Current Dummy Load Schematic (PDF)
Constant Current Dummy Load Bill of Materials (PDF)