Electronic Dummy Load

Searching the Internet you will find many varieties of Electronics dummy load projects. You will need this device when you want to create a load in your circuit, or to see how your well your battery or solar panel holding up. When you think creating a load that light bulb in your junk box no longer kick it, perhaps its time you need to buy or make your own dummy load device.

Even if you decide to buy, do your own research so that you know what you need.

We made one during last Christmas holidays, it was a fun project and it is a very useful tool.

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Since this project will be a prototype, passing along for internal use, we opt on a quick and dirty method. A project number (p-DRP-043) is assigned and off we go researching:

Here are all the websites we’ve been to while researching:







Now it’s time to search our parts bin to create a prototype.

We watched MJLorton YouTube videos on his dummy load research and build plans, not only he provided great project introduction, he included a variety of setup and testings to showcase why we need what we need. So we simply followed his guidance and picked our parts for the project.

Here are the components we opted for this project.

  • 4 x Mounting posts with Nuts and Bolts
  • 2 x Prototyping PCB PerfBoard 2.8 x 1.8 in (Datak 21-115)
  • 1 x Amplifier Terminal Binding Post Banana Jack
  • 1 x Clear lexan plastic board (Cut to fit the binding post)
  • 1 x Hopesun PM-2 Analog Ammeter
  • 1 x Pololu ACS714 Current Sensor Carrier -5 to +5A
  • 1 x LM324N op-amp
  • 1 x PF2472 (100W 1 ohm power resistor)
  • 1 x IRL520 N-Channel MOSFET (100V 9.2A, TO-220AB package)
  • 10K trim pot
  • Bourns 3540S-1-103 Precision Potentiometer (10 turn)

Our device features a double-deck stacking PCBs, with cables connecting to (i) External heatsink and (ii) Analog Ammeter. The quickest way to get components assembled is to place all control/logic components on the top PCB; power and ground routing on the bottom PCB.

We opted to power this device by separate power source (in this case a 9V battery)

The Pololu was a spare laying around from another research, we decided to hooked it up in case the device will communicate with any micro controller in the future.

Here is the back of both PCBs

We found an old CPU heat sink (Pentium class) with cooling fan. This is where we mounted the MOSFET and Power resistor.

With everything hooked up, we tested this device under 12V@5A for good 30 minutes. The computer heat sink with cooling fan works its magic and it is only warm to touch. We called it a success!


Team BTF

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